WO2018174981A1

WO2018174981A1 - Enhanced pilot tone sequences for wireless transmissions

Info

Publication number: WO2018174981A1
Application number: PCT/US2017/068445
Authority: WO
Inventors: Artyom LOMAYEV; Alexander Maltsev; Michael Genossar; Claudio Da Silva; Carlos Cordeiro
Original assignee: Intel IP Corporation
Priority date: 2017-03-23
Filing date: 2017-12-26
Publication date: 2018-09-27

Abstract

This disclosure describes systems, methods, and devices related to pilot sequence for wireless transmissions. A device may determine a space-time stream to send a signal on one or more channels. The device may determine one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-5 time stream. The device may send a signal a signal including the one or more OFDM pilot tone sequences.

Description

ENHANCED PILOT TONE SEQUENCES FOR WIRELESS TRANSMISSIONS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 62/541,508 filed August 4, 2017, entitled "Pilot Sequence Definition for Orthogonal Frequency-Division Multiplexing Physical Layer," the disclosure of which is incorporated by reference as if set forth in full.

TECHNICAL FIELD

[0002] This disclosure generally relates to systems and methods for wireless communications and, more particularly, to enhanced pilot tone sequences for wireless transmissions.

BACKGROUND

[0003] Wireless devices are becoming widely prevalent and are increasingly requesting access to wireless channels. The growing density of wireless deployments requires increased network and spectrum availability. Wireless devices may communicate with each other using directional transmission techniques, including but not limited to beamforming techniques. Wireless devices may communicate over a next generation 60 GHz (NG60) network, an enhanced directional multi-gigabit (EDMG) network, and/or any other network.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 depicts a network diagram illustrating an example network, in accordance with one or more example embodiments of the present disclosure.

[0005] FIG. 2 depicts an illustrative orthogonal frequency-division multiplexing (OFDM) physical layer (PHY) sequence, in accordance with one or more example embodiments of the present disclosure.

[0006] FIG. 3A illustrates a flow diagram of an illustrative process for using an enhanced pilot tone sequence, in accordance with one or more example embodiments of the present disclosure.

[0007] FIG. 3B illustrates a flow diagram of an illustrative process for using an enhanced pilot tone sequence, in accordance with one or more example embodiments of the present disclosure. [0008] FIG. 4 illustrates a functional diagram of an example communication station that may be suitable for use as a user device, in accordance with one or more example embodiments of the present disclosure.

[0009] FIG. 5 is a block diagram of an example machine upon which any of one or more techniques (e.g., methods) may be performed, in accordance with one or more example embodiments of the present disclosure.

DETAILED DESCRIPTION

[0010] Example embodiments described herein provide certain systems, methods, and devices for enhanced pilot sequences defined for an orthogonal frequency-division multiplexing (OFDM) physical layer (PHY). The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0011] Devices may communicate over a next generation 60 GHz (NG60) network, an enhanced directional multi-gigabit (EDMG) network, and/or any other network. Devices operating in EDMG may be referred to herein as EDMG devices. This may include user devices, and/or access points (APs) or other devices capable of communicating in accordance with a communication standard.

[0012] The IEEE 802.11 family of standards defines operations and parameters for wireless communications. A new IEEE 802.11 standard may define communications in a millimeter wave (mmWave, e.g., 60GHz) band, which represents an evolution of the IEEE 802. Had standard also known as WiGig. The IEEE 802.11 ay standard and other IEEE 802.11 standards may increase a transmission data rate applying Multiple Input Multiple Output (MIMO) and channel bonding techniques, for example.

[0013] A subcarrier (or tone) is a band of one or more frequencies that may be higher or lower than a carrier frequency. OFDM represents a multicarrier modulation scheme that allows for modulation of multiple subcarrier signals on multiple streams or channels. A resource unit (RU) may include a group of subcarriers as an allocation unit. There may be several types of subcarriers. One subcarrier type may be a data subcarrier (e.g., data tone), which may be used for data transmission. Data subcarriers may be frequency channel dependent. One subcarrier type may be a pilot subcarrier (e.g., pilot tone), which may be used for channel estimation and parameter tracking, such as carrier frequency offset and sampling frequency offset calculations. These calculations may be useful in making corrections at a device receiving the signal. Respective pilot subcarriers may be spaced by a constant step value, and therefore may have indexes referring to their location on a frequency spectrum. The frequency of a pilot tone may be used for determining a phase that may be used in demodulation of a signal, for example. Channel estimation using pilot subcarriers may allow for increased capacity of OFDM systems. One subcarrier type may be an unused subcarrier that is not used for either data or pilot transmission. Unused subcarriers may include a direct current (DC) subcarrier (e.g., a DC = 0 value), a Guard band subcarrier at band edges, and null subcarriers. Null subcarriers may be located near a DC or edge tone to protect those tones near the DC or edge tones from interference of a neighboring resource unit (RU). Null subcarriers may have zero energy.

[0014] An RU having a number of tones (e.g., signal sounds) may consist of a number of data and pilot subcarriers. For example, a 26-tone RU may consist of 24 data subcarriers and two pilot subcarriers. A 52-tone RU may consist of 48 data subcarriers and 4 pilot subcarriers. Other sizes of RUs may have different numbers of data and pilot subcarriers as defined by the IEEE 802.11 family of standards. The pilot subcarrier positions (e.g., indexes) of the RU may be fixed (e.g., as set in the IEEE 802.1 lad standard), or may vary as described herein (e.g., may be frequency channel dependent).

[0015] The location of OFDM signal tones may be defined by a grid or structure in a frequency domain. In particular, pilot subcarriers (e.g., tones) may be set in fixed locations for a given frequency channel. However, the grids defined by the IEEE 802.11 ad standard may not apply to a multi-channel or bonded channel environment such as those defined in the IEEE 802.1 lay standard and/or other IEEE 802.11 standards.

[0016] It may be desirable to define pilot tones and sequences in the IEEE 802. Hay standard and/or other IEEE 802.11 standards to account for a wider spectrum and to mitigate interference risks due to a MIMO environment with channel bonding availability, for example.

[0017] Example embodiments of the present disclosure relate to systems, methods, and devices for enhanced pilot sequences for wireless communications.

[0018] In one or more embodiments, pilot tones and pilot tone sequences may be defined for OFDM PHY in the IEEE 802. Hay standard. Pilot tones and sequences may be defined based on a channel bonding factor (NCB), which may be 1, 2, 3, or 4, for example. Pilot tone and sequence definitions also may depend on MIMO transmissions with one or more space- time streams (NSTS). The number of space-time streams may be any number up to eight (e.g., NSTS may be any number 1-8). [0019] In one or more embodiments, pilot tones and sequences may allow for both single input, single output (SISO) and MIMO channel estimation and tracking, common phase error estimation, sampling frequency estimation, and phase noise realization estimations.

[0020] In one or more embodiments, a pilot sequence including pilot tones may be created by inserting a sequence of zeros corresponding to tones occurring in a spectrum having a number of subcarriers (NSR), where the range of subcarriers in a bonded channel spans from - NSR to NSR. Pilots may be placed at tone indexes (e.g., frequency locations representing where tones are located on a spectrum), which may be frequency channel dependent, and also may be independent of a space-time stream or OFDM symbol number (e.g., the nth symbol including a sequence of pilot tones). Because tone indexes may be the same for different OFDM symbols sent in a same space-time stream, the pilot tones sequences of the respective OFDM symbols may be orthogonal to one another.

[0021] A pilot sequence for an OFDM PHY system may be defined. For example, pilot sequences may be defined in case of channel bonding transmission with NCB = 1, 2, 3, and 4 and MIMO transmission with the number of space-time streams up to NSTS = 8. This may allow SISO and MIMO channel estimation and tracking, common phase error estimation, sampling frequency estimation, and phase noise realization estimation.

[0022] MIMO may refer to a radio being divided into multiple chains that are able to transmit and receive data individually and/or simultaneously. Channel bonding may combine multiple communication links, which may allow for increased redundancy and/or increased throughput. In a MIMO environment with channel bonding, it may be important to avoid interference between multiple signals. For example, two signals with pilot tones may interfere with each other, thus undermining the ability of a receiving device to identify the pilot tones and facilitate channel estimations and other operational procedures. Therefore, it may be beneficial for all pilot tone sequences to be mutually orthogonal to one another (e.g., respective pilot tone sequences are at right angles to one another, meaning the dot product of two pilot tone sequences is zero). Orthogonality of tones/subcarriers may avoid interference between multiple signals. In addition, pilot tone sequences may have a low Peak-to- Average Power Ratio (PAPR) in a time domain.

[0023] In one or more embodiments, a pilot tone sequence may be defined as (e.g., PNSP(ISTS, .")), where NSP may correspond to the pilot tones based on the number of pilot tones in a sequence, isrs may represent the i-th spatial stream of the total number of spatial streams, and ":" may represent the range of subcarrier indexes. For example, when NSP = 16, the number of pilot tones is 16. [0024] In one or more embodiments, pilot tone sequences (e.g., PNSP(ISTS, :)) in a spatial stream may be orthogonal to one another, and in a bonded channel, a guard interval (e.g., guard band) may separate the pilot sequences. Not only may the pilot tone sequences be orthogonal to one another, but pilot tones sequences in guard intervals (e.g., NCB = 3, where two guard intervals may be present; NCB = 4, where three guard intervals may be present) may also be orthogonal to each other to avoid interference. Guard pilot tone sequences (e.g., PRISTS, ·")) may be mutually orthogonal in groups Z^'STS = 1, 2, 3, 4 and Z^'STS = 5, 6, 7, 8, where Z^'STS may be the ith spatial stream, and guard pilot tone sequences may have low PAPR in a time domain.

[0025] The above descriptions are for purposes of illustration and are not meant to be limiting. Numerous other examples, configurations, processes, etc., may exist, some of which are described in greater detail below. Example embodiments will now be described with reference to the accompanying figures.

[0026] FIG. 1 is a network diagram illustrating an example network, in accordance with one or more example embodiments of the present disclosure. Wireless network 100 may include one or more user device(s) 120 and one or more access point(s) (AP) 102, which may communicate in accordance with IEEE 802.11 communication standards, such as the IEEE 802.1 lad and/or IEEE 802. Hay specifications. The user device(s) 120 may be referred to as stations (STAs). The user device(s) 120 may be mobile devices that are non-stationary and do not have fixed locations. Although the AP 102 is shown to be communicating on multiple antennas with user devices 120, it should be understood that this is only for illustrative purposes and that any user device 120 may also communicate using multiple antennas with other user devices 120 and/or AP 102.

[0027] In some embodiments, the user device(s) 120 and the AP 102 may include one or more computer systems similar to that of the functional diagram of FIG. 4 and/or the example machine/system of FIG. 5.

[0028] One or more illustrative user device(s) 120 and/or AP 102 may be operable by one or more user(s) 110. The user device(s) 120 (e.g., 124, 126, or 128) and/or AP 102 may include any suitable processor-driven device including, but not limited to, a mobile device or a non- mobile, e.g., a static, device. For example, user device(s) 120 and/or AP 102 may include, a user equipment (UE), a station (STA), an access point (AP), a personal computer (PC), a wearable wireless device (e.g., bracelet, watch, glasses, ring, etc.), a desktop computer, a mobile computer, a laptop computer, an ultrabook^tm computer, a notebook computer, a tablet computer, a server computer, a handheld computer, a handheld device, an internet of things (IoT) device, a sensor device, a PDA device, a handheld PDA device, an on-board device, an off-board device, a hybrid device (e.g., combining cellular phone functionalities with PDA device functionalities), a consumer device, a vehicular device, a non-vehicular device, a mobile or portable device, a non-mobile or non-portable device, a mobile phone, a cellular telephone, a PCS device, a PDA device which incorporates a wireless communication device, a mobile or portable GPS device, a DVB device, a relatively small computing device, a non-desktop computer, a "carry small live large" (CSLL) device, an ultra mobile device (UMD), an ultra mobile PC (UMPC), a mobile internet device (MID), an "origami" device or computing device, a device that supports dynamically composable computing (DCC), a context-aware device, a video device, an audio device, an A/V device, a set-top-box (STB), a blu-ray disc (BD) player, a BD recorder, a digital video disc (DVD) player, a high definition (HD) DVD player, a DVD recorder, a HD DVD recorder, a personal video recorder (PVR), a broadcast HD receiver, a video source, an audio source, a video sink, an audio sink, a stereo tuner, a broadcast radio receiver, a flat panel display, a personal media player (PMP), a digital video camera (DVC), a digital audio player, a speaker, an audio receiver, an audio amplifier, a gaming device, a data source, a data sink, a digital still camera (DSC), a media player, a smartphone, a television, a music player, or the like. It is understood that the above is a list of devices. However, other devices, including smart devices, Internet of Things (IoT), such as lamps, climate control, car components, household components, appliances, etc. may also be included in this list.

[0029] Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to communicate with each other via one or more communications networks 130 and/or 135 wirelessly or wired. Any of the communications networks 130 and/or 135 may include, but not limited to, any one of a combination of different types of suitable communications networks such as, for example, broadcasting networks, cable networks, public networks (e.g., the Internet), private networks, wireless networks, cellular networks, or any other suitable private and/or public networks. Further, any of the communications networks 130 and/or 135 may have any suitable communication range associated therewith and may include, for example, global networks (e.g., the Internet), metropolitan area networks (MANs), wide area networks (WANs), local area networks (LANs), or personal area networks (PANs). In addition, any of the communications networks 130 and/or 135 may include any type of medium over which network traffic may be carried including, but not limited to, coaxial cable, twisted-pair wire, optical fiber, a hybrid fiber coaxial (HFC) medium, microwave terrestrial transceivers, radio frequency communication mediums, white space communication mediums, ultra-high frequency communication mediums, satellite communication mediums, or any combination thereof. [0030] Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may include one or more communications antennas. The one or more communications antennas may be any suitable type of antennas corresponding to the communications protocols used by the user device(s) 120 (e.g., user devices 124, 126 and 128), and AP 102. Some non-limiting examples of suitable communications antennas include Wi-Fi antennas, Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards compatible antennas, directional antennas, non-directional antennas, dipole antennas, folded dipole antennas, patch antennas, multiple-input multiple-output (MIMO) antennas, or the like. The one or more communications antennas may be communicatively coupled to a radio component to transmit and/or receive signals, such as communications signals to and/or from the user devices 120 and/or AP 102.

[0031] Any of the user devices 120 (e.g., user devices 124, 126, 128), and AP 102 may include multiple antennas that may include one or more directional antennas. The one or more directional antennas may be steered to a plurality of beam directions. For example, at least one antenna of a user device 120 (or an AP 102) may be steered to a plurality of beam directions. For example, a user device 120 (or an AP 102) may transmit a directional transmission to another user device 120 (or another AP 102).

[0032] Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform directional transmission and/or directional reception in conjunction with wirelessly communicating in a wireless network. Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform such directional transmission and/or reception using a set of multiple antenna arrays (e.g., DMG antenna arrays or the like). Each of the multiple antenna arrays may be used for transmission and/or reception in a particular respective direction or range of directions. Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform any given directional transmission towards one or more defined transmit sectors. Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform any given directional reception from one or more defined receive sectors.

[0033] MIMO beamforming in a wireless network may be accomplished using RF beamforming and/or digital beamforming. In some embodiments, in performing a given MIMO transmission, user devices 120 and/or AP 102 may be configured to use all or a subset of its one or more communications antennas to perform MIMO beamforming.

[0034] Any of the user devices 120 (e.g., user devices 124, 126, 128), and AP 102 may include any suitable radio and/or transceiver for transmitting and/or receiving radio frequency (RF) signals in the bandwidth and/or channels corresponding to the communications protocols utilized by any of the user device(s) 120 and AP 102 to communicate with each other. The radio components may include hardware and/or software to modulate and/or demodulate communications signals according to pre-established transmission protocols. The radio components may further have hardware and/or software instructions to communicate via one or more Wi-Fi and/or Wi-Fi direct protocols, as standardized by the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards. In certain example embodiments, the radio component, in cooperation with the communications antennas, may be configured to communicate via 2.4 GHz channels (e.g. 802.11b, 802. llg, 802.11η, 802.1 lax), 5 GHz channels (e.g. 802.11η, 802.11ac, 802.11ax), or 60 GHZ channels (e.g. 802.11ad, 802.11ay). In some embodiments, non- Wi-Fi protocols may be used for communications between devices, such as Bluetooth, dedicated short-range communication (DSRC), Ultra-High Frequency (UHF) (e.g. IEEE 802.1 laf, IEEE 802.22), white band frequency (e.g., white spaces), or other packetized radio communications. The radio component may include any known receiver and baseband suitable for communicating via the communications protocols. The radio component may further include a low noise amplifier (LNA), additional signal amplifiers, an analog-to- digital (A/D) converter, one or more buffers, and digital baseband.

[0035] Some demonstrative embodiments may be used in conjunction with a wireless communication network communicating over a frequency band of 60 GHz. However, other embodiments may be implemented utilizing any other suitable wireless communication frequency bands, for example, an extremely high frequency (EHF) band (the millimeter wave (mmWave) frequency band), a frequency band within the frequency band of between 20 GHz and 300 GHz, a WLAN frequency band, a WPAN frequency band, a frequency band according to the WGA specification, and the like.

[0036] The phrases "directional multi-gigabit (DMG)" and "directional band (DBand)", as used herein, may relate to a frequency band wherein the channel starting frequency is above 45 GHz. In one example, DMG communications may involve one or more directional links to communicate at a rate of multiple gigabits per second, for example, at least 1 gigabit per second, 7 gigabits per second, or any other rate.

[0037] In some demonstrative embodiments, the user device(s) 120 and/or the AP 102 may be configured to operate in accordance with one or more specifications, including one or more IEEE 802.11 specifications, (e.g., an IEEE 802.1 lad specification, an IEEE 802.1 lay specification, and/or any other specification and/or protocol). For example, an amendment to a DMG operation in the 60 GHz band, according to an IEEE 802.1 lad standard, may be defined, for example, by an IEEE 802. Hay project.

[0038] It is understood that a basic service set (BSS) provides the basic building block of an 802.11 wireless LAN. For example, in infrastructure mode, a single access point (AP) together with all associated stations (STAs) is called a BSS.

[0039] In one embodiment, and with reference to FIG. 1, when an AP (e.g., AP 102) establishes communication with one or more user devices 120 (e.g., user devices 124, 126, and/or 128), the AP 102 may communicate in a downlink direction and the user devices 120 may communicate with the AP 102 in an uplink direction by sending signals/frames (e.g., signal 140) in either direction. A device (e.g., user devices 120 and/or AP 102) may respond to receiving a frame by sending a response frame 142. The user devices 120 may also communicate peer-to-peer or directly with each other with or without the AP 102. The data frames may be preceded by one or more preambles that may be part of one or more headers. These preambles may be used to allow a device (e.g., AP 102 and/or user devices 120) to detect a new incoming data frame from another device. A preamble may be a signal used in network communications to synchronize transmission timing between two or more devices (e.g., between the APs and user devices).

[0040] In one or more embodiments, AP 102 and user device(s) 120 may send one or more signals (e.g., signal 140) having one or more tones (e.g., pilot tones, data tones, etc.) to each other over one or more channels.

[0041] In one or more embodiments, a single unbonded channel (e.g., 2.16 GHz) may be used to send a signal, and a sequence of sixteen pilot tones may be defined and uniformly distributed for an OFDM symbol sent over an OFDM signal spectrum with an equidistant step (e.g., twenty subcarriers).

[0042] A pilot sequence may depend on a k-th subcarrier index and an n-th OFDM symbol number.

[0043] For example, the pilot sequence may be defined as P(k, n) =

* W(n); where p₁₆ = [-1, +1, -1, +1, +1, -1, -1, -1, -1, -1, +1, +1, +1, -1, +1, +1]; where W(n) = 2*p(n)-l, where p(n) may define a bit coming from the scrambler (e.g., a 0 or 1 bit), initialized to all ones at a first OFDM symbol.

[0044] The +1 and -1 values of Pie may be values at respective subcarriers at a given spatial stream, and k may be a kth subcarrier index. Thus, the sequence of Is and -Is of Pie may be multiplied by (e.g., applied to) the bit from the scrambler. [0045] For example, if the p(n) bit from a scrambler is a 0, then W(n) = 2*p(n)-l = 2*0-1= -1 , so P(k, n) = Pie(k) * W(n) = -1* Pie(k) (e.g., each pilot tone value of Pie(k) is inverted, representing a phase shift). If the p(n) bit from a scrambler is a 1, then W(n) = 2*p(n)- l = 2* 1- 1= +1, so P(k, n) = Pie(k) * W(n) = 1 * Pie(k) (e.g., the sequence Pie(k) is unchanged).

[0046] In one or more embodiments, W(n) may be defined equal to an exponent:

[0047] W(n) = -exp(-j *ji*p(ft)); where p(n) may define a bit coming from the scrambler (e.g., a 0 or 1 bit).

[0048] In one or more embodiments, pilot tones may have fixed locations with indexes p_idx = [-150:20: 150] ; where 20 may be a step value, which may vary, and where the range of -150 to 150 may be an index location range according to a spectrum. Therefore, a pilot sequence may be unchanged over OFDM symbols except for the common phase defined by a W(n) multiplier, which may change from 0 to π. Because the range of pilot indexes is between -150 and 150 with a step of 20, there may be sixteen pilot indexes (e.g., - 150, - 130, - 110, -90, -70, -50, -30, - 10, 10, 30, 50, 70, 90, 110, 130, and 150), hence Pie may have sixteen values of +1 and/or -1.

[0049] In one or more embodiments, the +1 and/or -1 pilot tone values of Pie may represent a phase shift based on binary phase shift keying (BPSK) modulation, and the values may always end up as a plus or minus one value. Thus, the values of P may always be one, but the phase may be positive or negative, resulting in values of +1 and - 1 for Pie.

[0050] In one or more embodiments, additional definitions of pilot tones and sequences may depend on spatial streams and a number of bonded channels used to send a signal with the pilot tones. For example, pilot indexes may be different in an environment which allows channel bonding and MIMO transmissions.

[0051] It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0052] FIG. 2 depicts an illustrative OFDM PHY sequence 200, in accordance with one or more example embodiments of the present disclosure.

[0053] In one or more embodiments, an IEEE 802.11 standard (e.g., the IEEE 802.1 lay standard) may define pilot tones (e.g., pilot tones 202, pilot tones 206, pilot tones 212) and guard pilot tones (e.g., guard tones 204, guard tones 208, guard tones 210) for OFDM PHY sequence 200 sent in a channel 214. A pilot sequence tone sequence may include one or more pilot tones, and may be created by inserting a sequence of zeros corresponding to tones according to a range of subcarriers -NSR to NSR in a spectrum. The pilot tones may be inserted at tone indexes that may be frequency channel dependent, but independent of a space-time stream or OFDM symbol number.

[0054] Guard intervals including guard pilot tones (e.g., guard tones 204, guard tones 208, guard tones 210) may improve the tone coverage of a spectrum using a bonded channel. For example, bonded channels may result in a wider spectrum. Without guard intervals, signals sent over bonded channels (e.g., channel 214) may experience interference. Using guard intervals lacking pilot tones may result in areas of a spectrum where pilot tones may not be used for channel estimation and other operational determinations, which may impair communications. By using guard pilot tones in guard intervals, more pilot tones may be included in a signal, resulting in better reliability and increased spectrum coverage. As such, the number of pilot tones may remain proportional to the bandwidth (e.g., as related to NCB).

[0055] For example, channel 214 may be a bonded (e.g., NCB>1) or an unbonded channel (e.g., NCB=1). OFDM PHY sequence 200 may be sent using a spatial stream of the one or more channels represented by channel 214. For example, one spatial stream may be part of a single unbonded channel, and another spatial stream may be part of a bonded channel including two or more sub-channels.

[0056] The number of pilot tones and pilot tone sequences may depend on NCB. For example, when NCB=1 (e.g., a 2.16 GHz channel), one sequence of pilot tones (e.g., pilot tones 202) may be used for a given spatial stream. In an environment with multiple channels, however, pilot indexes may be channel dependent to avoid interference. This means, for example, that applying p_idx = [-150:20:150] across multiple channels may not be desirable in all cases, especially in MIMO and channel bonding situations.

[0057] When NCB is greater than one, a bonded channel may form, and additional pilot tones may be used. For example, to separate pilot sequences applied in the channels used to create a bonded channel, guard tones (e.g., guard tones 204, guard tones 208, and guard tones 210) may be used in between pilot tones (e.g., in between pilot tones 202 and pilot tones 206). Guard tones may include guard pilot tones. For example, in a guard interval having the guard tones, four guard pilot tones may occur, thus allowing for pilots to occur during guard intervals used in bonded channels.

[0058] In one or more embodiments, when a bonded channel is used, pilot tone sequences may need to account for pilot tones and guard pilot tones in the bonded channel. For example, when NCB=2 (e.g., a 4.32 GHz channel), two pilot tone sequences may be used (e.g., pilot tones 202, pilot tones 206), and may include guard pilot tones (e.g., guard tones 204) in between them. Pilot tone sequences may include sixteen pilot tones, and the sequences may be orthogonal to each other. To separate the orthogonal pilot tone sequences sent in an OFDM signal in a bonded channel, guard intervals with guard pilot tones may be inserted in between the pilot tone sequences. When NCB=3 or 4, multiple guard intervals with guard pilot tones may be used. For example, when NCB=3 (e.g., a 6.48 GHz channel), three pilot tone sequences may be used, and two guard intervals may be inserted in between them (e.g., between first and second pilot tone sequences, and between second and third pilot tone sequences). When NCB=4 (e.g., an 8.64 GHz channel), four pilot tone sequences may be used, and two guard intervals may be inserted in between them (e.g., between first and second pilot tone sequences, between second and third pilot tone sequences, and between third and fourth pilot tone sequences). The relationship between pilot tone sequences and NCB is shown in Table 1 below.

[0059] Table 1: Pilot Sequence PNSP(ISTS, :) Definition.

[0060] In one or more embodiments, the pilot value PNSP(ISTS, n, k) may depend on isrs-th space-time stream number, an n-th OFDM symbol number, a k-th subcarrier index, and may be defined as PNSP(ISTS, n, k) = W(isrs, mod(n - 1, NSTS) + 1) * (2*p(n) - 1) * PNSP(ISTS, k), where PNSp(isrs, k) may define a pilot for an isrs-th space-time stream and a k-th subcarrier index, WO^'sra, n) * {2* p{n) - 1) may define a common phase shift (e.g., over subcarriers) for an isrs- th space-time stream and an n-th OFDM symbol (e.g., n = 1, 2,..., NSYMB, where NsYMB may be the total number of symbols in a frame), pin) may define a bit coming from the scrambler with a shift register xi, x₂₎..., x₇ initialized to all ones at a first OFDM symbol, Nsrs may define a total number of space-time streams, and mod(x, N) may define a modulo N operation. For example, if Nsrs is 2, then W = [+1, +1, +1, -1]. For the first stream, PNSpiisrs = 1, :) = W * (2* pin) - 1), resulting in a value dependent on the OFDM symbol number n. The first OFDM symbol n may then be multiplied by 1, the second OFDM symbol n may be multiplied by 1, and then repeat values from the first row of matrix W (e.g., 1, 1,..., NSYMB). For the second stream, PNSpiisrs= 2, :) = W * (2* pin) - 1), resulting in a value dependent on the OFDM symbol number n. The first OFDM symbol n may then be multiplied by 1, the second OFDM symbol n may be multiplied by -1, and then repeat values from the second row of matrix W (e.g., 1, - 1 , . . . , NSYMB). Therefore, W values may be an exponent with unit power and some phase depending on isrs and n.

[0061 ] In one or more embodiments, common phase shift W(isrs, ri) * (2*p(n) - 1) may be composed as a product of a deterministic shift W(isrs, n) repeated with a period NsTs over a time and a random shift defined by (2*p(n) - 1), which may be scrambler output dependent (e.g., a 0 bit or a 1 bit). The random component (2*p(n) - 1), may depend on an n-th OFDM symbol number and may not depend on a particular z^'sTs-th space-time stream number.

[0062] In one or more embodiments, when NCB= 1 , a single Pieiisrs, ·") sequence may be used for a signal. The Pieiisrs, ·") sequence may include sixteen pilot tone indexes (e.g., Pie).

[0063] In one or more embodiments, when NCB=2, two Pieiisrs, ·") sequences may be used for a signal. To separate the two Pieiisrs, ·") sequences, a PRISTS, ·") guard pilot tone sequence may be included in between the two Pieiisrs, ·") sequences, resulting in a total of 36 pilot tone indexes (e.g., 2* 16 + 4 = 36, thus ¾).

[0064] In one or more embodiments, when NCB =3, three Pieiisrs, ·") sequences may be used for a signal. To separate the three Pi6(isrs, :) sequences, a first PRISTS, :) guard pilot tone sequence may be included in between a first of the Pieiisrs, ·") sequences and a second of the PieiisTS, ·") sequences, and a second PRISTS, ·") guard pilot tone sequence may be included in between a second of the Pi6(isrs, :) sequences and a third of the Pi6(isrs, :) sequences, resulting in a total of 56 pilot tone indexes (e.g., 3 * 16 + 4 + 4 = 56, thus

[0065] In one or more embodiments, when NCB =4, four Pieiisrs, ·") sequences may be used for a signal. To separate the four Pieiisrs, ·") sequences, a first PRISTS, ·") guard pilot tone sequence may be included in between a first of the Pieiisrs, ·") sequences and a second of the PieiisTS, ·") sequences, a second PRISTS, ·") guard pilot tone sequence may be included in between a second of the Pieiisrs, ·") sequences and a third of the Pieiisrs, ·") sequences, and a third PRISTS, :) guard pilot tone sequence may be included in between a third of the Pieiisrs, ·") sequences and a fourth of the Pieiisrs, ·") sequences resulting in a total of 76 pilot tone indexes (e.g., 4* 16 + 4 + 4 + 4 = 76, thus P₇₆).

[0066] In one or more embodiments, pilot sequences Pieiisrs, ·") and PRISTS, ·") may be defined as sequences of pilot values for pilot tones and guard pilot tones. The pilot sequences Pie(isTS, :) and PRISTS, .") are defined in Table below. [0067] Table 2: Pilot sequences Pie(iSTS, :) and P₄(iSTS, :) definition.

[0068] In one or more embodiments, sequences Pieiisrs, ·") may be mutually orthogonal from one another, and may have low PAPR in a time domain. For example,

·") may be orthogonal from the other Pieiisrs, :) sequences, and so on. Guard pilot tone sequences PRISTS, ·") may be mutually orthogonal in groups of Z^'STS = 1, 2, 3, 4 and Z^'STS = 5, 6, 7, 8, and may have low PAPR in time domain. For example, P4(isrs=l, :) may be orthogonal from other P4(isTS, :) guard pilot tone sequences, and so on. The +1 and -1 values may be pilot tone values corresponding to pilot tone indexes, so orthogonality among sequences may allow for pilot tones at respective indexes in one or more channels to be sent with reduced interference.

[0069] In one or more embodiments, the deterministic component of the common phase shift W(isTS, n) may be defined as w(i_STS , n) -- exp - (i_STS - l)- (n - l) , i_STS = 1,2,..., N_STS ; n = l,2,..., N_STS , where j may be

an imaginary number, N_STS may be the number of spatial streams, i_STS may be the ith spatial stream from 1- N_STS , and n may be an nth OFDM symbol number from 1- N_STS . Thus, W(isrs, n) may be a square matrix having the same number of rows as number of columns, N_STS . The space -time, matrix W may be defined as any orthogonal matrix, for example, as Hadamard matrix, discrete Fourier transform (DFT) matrix, or another orthogonal matrix.

[0070] In one or more embodiments, the mod(x, N) operation may be used to accommodate the number of OFDM symbols n being larger than the number of space-time streams NSTS. For simplicity, W(isrs, n) may limit n to a range of 1- NSTS- However, the number of OFDM symbols may be larger than NSTS- AS such, for values of W(isrs, n) when n is greater than NSTS, n restarts at n=l (e.g., n = NSTS+1=1). This way, W(isrs, n) may provide simplicity in the PNSP(ISTS, n, k) = W(isrs, mod(n - 1, NSTS) + 1) * (2*p(n) - 1) * PNSP(ISTS, k) calculation. Because (2*p(n) - 1) * PNSp(isTS, k) should produce values of +1 and -1, and because pilot tone values of PNSP(ISTS, n, k) should be +1 and - 1, the values of W(isrs, mod(n - 1, NSTS) + 1) should also be +1 or - 1. The modulo operation may allow for application of W(isrs, ri) in determining PNSP(ISTS, n, k) by facilitating the output of W(isrs, ri) as values +1 or -1. For example, W(isrs, ri) may result in values of +1 or - 1 because exp may result in exp(0)

= 1 or exp( - j 7Γ ) = -1 when n is limited to a range from 1 to NSTS which is repeated when n >

NSTS (e.g., n = NSTS + 1 = 1), and because n is represented in W(ISTS, ri) by mod(« - 1, NSTS) + 1.

[0071] It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0072] FIG. 3A illustrates a flow diagram of illustrative process 300 for using an enhanced pilot sequence, in accordance with one or more example embodiments of the present disclosure.

[0073] At block 302, one or more processors of a device (e.g., the user device(s) 120 and/or the AP 102 of FIG. 1) may determine a space-time stream to send a signal on one or more channels. The one or more channels may be associated with a channel bonding factor NCB, which may be 1, 2, 3, 4. If NCB is 1, then the channel may be unbonded. When NCB is greater than 1, a bonded channel may be formed using multiple sub-channels. Bonded channels may provide a wider spectrum than unbonded channels, and may use guard intervals to separate signals/sequences sent in the channels.

[0074] At block 304, the one or more processors of the device may determine one or more OFDM pilot tone sequences associated with the space-time stream. The one or more OFDM pilot tone sequences may be based on the channel bonding factor. For example, an unbonded channel may use a single pilot tone sequence, and a bonded channel may use multiple pilot tone sequences. When multiple pilot tone sequences are used, a guard band with guard pilot tones may be used to separate the respective pilot tone sequences and to account for a wider spectrum. The pilot tone sequences may have pilot tones according to pilot tone index locations that may be dependent on the channel, but independent of a space-time stream used to send the signal. A pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences is based on a deterministic component of a phase shift represented by an orthogonal space-time matrix, and wherein the orthogonal space-time matrix is a square matrix with a dimension of a total number of streams.

[0075] At block 306, the one or more processors of the device may cause the device to send a signal including the one or more OFDM pilot tone sequences. The signal may be sent over the one or more channels, which may be a bonded or unbonded channel. When sending multiple symbols in a signal, it may be beneficial to provide orthogonality between pilot tone sequences to avoid interference.

[0076] It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0077] FIG. 3B illustrates a flow diagram of illustrative process 350 for using an enhanced pilot sequence, in accordance with one or more example embodiments of the present disclosure.

[0078] At block 352, one or more processors of a device (e.g., the user device(s) 120 and/or the AP 102 of FIG. 1) may identify a signal received on a space-time stream associated with one or more channels. The one or more channels may be associated with a channel bonding factor, which may be 1, 2, 3, 4. If NCB is 1, then the channel may be unbonded. When NCB is greater than 1, a bonded channel may be formed using multiple sub-channels. Bonded channels may provide a wider spectrum than unbonded channels, and may use guard intervals to separate signals/sequences sent in the channels. The guard intervals may have one or more guard pilot tones.

[0079] At block 354, the one or more processors of the device may determine one or more OFDM pilot tone sequences associated with the space-time stream. The one or more OFDM pilot tone sequences may be based on a channel bonding factor. For example, an unbonded channel may use a single pilot tone sequence, and a bonded channel may use multiple pilot tone sequences. When multiple pilot tone sequences are used, a guard band with guard pilot tones may be used to separate the respective pilot tone sequences and to account for a wider spectrum. The pilot tone sequences may have pilot tones according to pilot tone index locations that may be dependent on the channel, but independent of a space-time stream used to send the signal. A pilot value of an OFDM pilot tone of the OFDM pilot tones is based on a deterministic component of a phase shift represented by an orthogonal space-time matrix w(i _STS , n) , wherein

, , n) = expl - j-^— (i_STS - 1) - (n 1,2,..., N_m ;n = 1,2,..., N_m , wherein j^" is the 1^th spatial stream of the one or more space-time streams, wherein N_STS is a total number of the one or more space-time streams, wherein j is an imaginary number, wherein the pilot value is represented by PNSP(ISTS, n, k), wherein n is an n* OFDM symbol number, wherein k is a k* subcarrier index, wherein PNSP(ISTS, n, k) = W(isrs, mod(« - 1, NSTS) + 1) * (2*p(n) - 1) * PNSP(ISTS, k), and wherein mod defines a modulo operation.

[0080] At block 356, the one or more processors of the device may determine a frequency offset based on the one or more OFDM pilot tone sequences. Other channel estimation and adjustments may be performed based on pilot tones.

[0081] It is understood that the above descriptions are for purposes of illustration and are not meant to be limiting.

[0082] FIG. 4 shows a functional diagram of an exemplary communication station 400 in accordance with some embodiments. In one embodiment, FIG. 4 illustrates a functional block diagram of a communication station that may be suitable for use as an AP 102 (FIG. 1) or user device 120 (FIG. 1) in accordance with some embodiments. The communication station 400 may also be suitable for use as a handheld device, a mobile device, a cellular telephone, a smartphone, a tablet, a netbook, a wireless terminal, a laptop computer, a wearable computer device, a femtocell, a high data rate (HDR) subscriber station, an access point, an access terminal, or other personal communication system (PCS) device.

[0083] The communication station 400 may include communications circuitry 402 and a transceiver 410 for transmitting and receiving signals to and from other communication stations using one or more antennas 401. The transceiver 410 may be a device comprising both a transmitter and a receiver that are combined and share common circuitry (e.g., communication circuitry 402). The communication circuitry 402 may include amplifiers, filters, mixers, analog to digital and/or digital to analog converters. The transceiver 410 may transmit and receive analog or digital signals. The transceiver 410 may allow reception of signals during transmission periods. This mode is known as full-duplex, and may require the transmitter and receiver to operate on different frequencies to minimize interference between the transmitted signal and the received signal. The transceiver 410 may operate in a half-duplex mode, where the transceiver 410 may transmit or receive signals in one direction at a time.

[0084] The communications circuitry 402 may include circuitry that can operate the physical layer (PHY) communications and/or media access control (MAC) communications for controlling access to the wireless medium, and/or any other communications layers for transmitting and receiving signals. The communication station 400 may also include processing circuitry 406 and memory 408 arranged to perform the operations described herein. In some embodiments, the communications circuitry 402 and the processing circuitry 406 may be configured to perform operations detailed in detailed in FIGs. 2, 3A, and 3B.

[0085] In accordance with some embodiments, the communications circuitry 402 may be arranged to contend for a wireless medium and configure frames or packets for communicating over the wireless medium. The communications circuitry 402 may be arranged to transmit and receive signals. The communications circuitry 402 may also include circuitry for modulation/demodulation, upconversion/downconversion, filtering, amplification, etc. In some embodiments, the processing circuitry 406 of the communication station 400 may include one or more processors. In other embodiments, two or more antennas 401 may be coupled to the communications circuitry 402 arranged for sending and receiving signals. The memory 408 may store information for configuring the processing circuitry 406 to perform operations for configuring and transmitting message frames and performing the various operations described herein. The memory 408 may include any type of memory, including non-transitory memory, for storing information in a form readable by a machine (e.g., a computer). For example, the memory 408 may include a computer-readable storage device , read-only memory (ROM), random- access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices and other storage devices and media.

[0086] In some embodiments, the communication station 400 may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), a wearable computer device, or another device that may receive and/or transmit information wirelessly.

[0087] In some embodiments, the communication station 400 may include one or more antennas 401. The antennas 401 may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some embodiments, instead of two or more antennas, a single antenna with multiple apertures may be used. In these embodiments, each aperture may be considered a separate antenna. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be effectively separated for spatial diversity and the different channel characteristics that may result between each of the antennas and the antennas of a transmitting station.

[0088] In some embodiments, the communication station 400 may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0089] Although the communication station 400 is illustrated as having several separate functional elements, two or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio- frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements of the communication station 400 may refer to one or more processes operating on one or more processing elements.

[0090] Certain embodiments may be implemented in one or a combination of hardware, firmware, and software. Other embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory memory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. In some embodiments, the communication station 400 may include one or more processors and may be configured with instructions stored on a computer-readable storage device memory.

[0091] FIG. 5 illustrates a block diagram of an example of a machine 500 or system upon which any one or more of the techniques (e.g., methodologies) discussed herein may be performed. In other embodiments, the machine 500 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 500 may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, the machine 500 may act as a peer machine in peer-to- peer (P2P) (or other distributed) network environments. The machine 500 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a wearable computer device, a web appliance, a network router, a switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine, such as a base station. Further, while only a single machine is illustrated, the term "machine" shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), or other computer cluster configurations. [0092] Examples, as described herein, may include or may operate on logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations when operating. A module includes hardware. In an example, the hardware may be specifically configured to carry out a specific operation (e.g., hardwired). In another example, the hardware may include configurable execution units (e.g., transistors, circuits, etc.) and a computer readable medium containing instructions where the instructions configure the execution units to carry out a specific operation when in operation. The configuring may occur under the direction of the executions units or a loading mechanism. Accordingly, the execution units are communicatively coupled to the computer-readable medium when the device is operating. In this example, the execution units may be a member of more than one module. For example, under operation, the execution units may be configured by a first set of instructions to implement a first module at one point in time and reconfigured by a second set of instructions to implement a second module at a second point in time.

[0093] The machine (e.g., computer system) 500 may include a hardware processor 502 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 504 and a static memory 506, some or all of which may communicate with each other via an interlink (e.g., bus) 508. The machine 500 may further include a power management device 532, a graphics display device 510, an alphanumeric input device 512 (e.g., a keyboard), and a user interface (UI) navigation device 514 (e.g., a mouse). In an example, the graphics display device 510, alphanumeric input device 512, and UI navigation device 514 may be a touch screen display. The machine 500 may additionally include a storage device (i.e., drive unit) 516, a signal generation device 518 (e.g., a speaker), an enhanced pilot tone device 519, a network interface device/transceiver 520 coupled to antenna(s) 530, and one or more sensors 528, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or other sensor. The machine 500 may include an output controller 534, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate with or control one or more peripheral devices (e.g., a printer, a card reader, etc.)).

[0094] The storage device 516 may include a machine readable medium 522 on which is stored one or more sets of data structures or instructions 524 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 524 may also reside, completely or at least partially, within the main memory 504, within the static memory 506, or within the hardware processor 502 during execution thereof by the machine 500. In an example, one or any combination of the hardware processor 502, the main memory 504, the static memory 506, or the storage device 516 may constitute machine- readable media.

[0095] The enhanced pilot tone device 519 may carry out or perform any of the operations and processes (e.g., process 300 of FIG. 3A, process 350 of FIG. 3B) described and shown above.

[0096] In one or more embodiments, enhanced pilot tone device 519 may determine a space-time stream to send a signal on one or more channels, wherein the one or more channels are associated with a channel bonding factor.

[0097] In one or more embodiments, enhanced pilot tone device 519 may determine one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on the channel bonding factor.

[0098] In one or more embodiments, enhanced pilot tone device 519 may cause to send, over the one or more channels, a signal comprising the one or more OFDM pilot tone sequences.

[0099] In one or more embodiments, enhanced pilot tone device 519 may identify a signal received on a space-time stream associated with one or more channels, wherein the one or more channels are associated with a channel bonding factor.

[00100] In one or more embodiments, enhanced pilot tone device 519 may determine one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on a channel bonding factor.

[00101] In one or more embodiments, enhanced pilot tone device 519 may determine a frequency offset based on the one or more OFDM pilot tone sequences.

[00102] It is understood that the above are only a subset of what the enhanced pilot tone device 519 may be configured to perform and that other functions included throughout this disclosure may also be performed by the enhanced pilot tone device 519.

[00103] While the machine-readable medium 522 is illustrated as a single medium, the term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 524.

[00104] Various embodiments may be implemented fully or partially in software and/or firmware. This software and/or firmware may take the form of instructions contained in or on a non-transitory computer-readable storage medium. Those instructions may then be read and executed by one or more processors to enable performance of the operations described herein. The instructions may be in any suitable form, such as but not limited to source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. Such a computer-readable medium may include any tangible non-transitory medium for storing information in a form readable by one or more computers, such as but not limited to read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; a flash memory, etc.

[00105] The term "machine-readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine 500 and that cause the machine 500 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding, or carrying data structures used by or associated with such instructions. Non-limiting machine-readable medium examples may include solid-state memories and optical and magnetic media. In an example, a massed machine -readable medium includes a machine-readable medium with a plurality of particles having resting mass. Specific examples of massed machine -readable media may include non-volatile memory, such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), or electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD- ROM disks.

[00106] The instructions 524 may further be transmitted or received over a communications network 526 using a transmission medium via the network interface device/transceiver 520 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communications networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), plain old telephone (POTS) networks, wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi®, IEEE 802.16 family of standards known as WiMax®), IEEE 802.15.4 family of standards, and peer-to-peer (P2P) networks, among others. In an example, the network interface device/transceiver 520 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 526. In an example, the network interface device/transceiver 520 may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple- output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the machine 500 and includes digital or analog communications signals or other intangible media to facilitate communication of such software. The operations and processes described and shown above may be carried out or performed in any suitable order as desired in various implementations. Additionally, in certain implementations, at least a portion of the operations may be carried out in parallel. Furthermore, in certain implementations, less than or more than the operations described may be performed.

[00107] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The terms "computing device," "user device," "communication station," "station," "handheld device," "mobile device," "wireless device" and "user equipment" (UE) as used herein refers to a wireless communication device such as a cellular telephone, a smartphone, a tablet, a netbook, a wireless terminal, a laptop computer, a femtocell, a high data rate (HDR) subscriber station, an access point, a printer, a point of sale device, an access terminal, or other personal communication system (PCS) device. The device may be either mobile or stationary.

[00108] As used within this document, the term "communicate" is intended to include transmitting, or receiving, or both transmitting and receiving. This may be particularly useful in claims when describing the organization of data that is being transmitted by one device and received by another, but only the functionality of one of those devices is required to infringe the claim. Similarly, the bidirectional exchange of data between two devices (both devices transmit and receive during the exchange) may be described as "communicating," when only the functionality of one of those devices is being claimed. The term "communicating" as used herein with respect to a wireless communication signal includes transmitting the wireless communication signal and/or receiving the wireless communication signal. For example, a wireless communication unit, which is capable of communicating a wireless communication signal, may include a wireless transmitter to transmit the wireless communication signal to at least one other wireless communication unit, and/or a wireless communication receiver to receive the wireless communication signal from at least one other wireless communication unit.

[00109] As used herein, unless otherwise specified, the use of the ordinal adjectives "first," "second," "third," etc., to describe a common object, merely indicates that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[00110] The term "access point" (AP) as used herein may be a fixed station. An access point may also be referred to as an access node, a base station, an evolved node B (eNodeB), or some other similar terminology known in the art. An access terminal may also be called a mobile station, user equipment (UE), a wireless communication device, or some other similar terminology known in the art. Embodiments disclosed herein generally pertain to wireless networks. Some embodiments may relate to wireless networks that operate in accordance with one of the IEEE 802.11 standards.

[00111] Some embodiments may be used in conjunction with various devices and systems, for example, a personal computer (PC), a desktop computer, a mobile computer, a laptop computer, a notebook computer, a tablet computer, a server computer, a handheld computer, a handheld device, a personal digital assistant (PDA) device, a handheld PDA device, an onboard device, an off-board device, a hybrid device, a vehicular device, a non- vehicular device, a mobile or portable device, a consumer device, a non- mobile or non-portable device, a wireless communication station, a wireless communication device, a wireless access point (AP), a wired or wireless router, a wired or wireless modem, a video device, an audio device, an audio- video (A/V) device, a wired or wireless network, a wireless area network, a wireless video area network (WVAN), a local area network (LAN), a wireless LAN (WLAN), a personal area network (PAN), a wireless PAN (WPAN), and the like.

[00112] Some embodiments may be used in conj unction with one way and/or two-way radio communication systems, cellular radio-telephone communication systems, a mobile phone, a cellular telephone, a wireless telephone, a personal communication system (PCS) device, a PDA device which incorporates a wireless communication device, a mobile or portable global positioning system (GPS) device, a device which incorporates a GPS receiver or transceiver or chip, a device which incorporates an RFID element or chip, a multiple input multiple output (MIMO) transceiver or device, a single input multiple output (SIMO) transceiver or device, a multiple input single output (MISO) transceiver or device, a single input single output (SISO) transceiver or device, a device having one or more internal antennas and/or external antennas, digital video broadcast (DVB) devices or systems, multi- standard radio devices or systems, a wired or wireless handheld device, e.g., a smartphone, a wireless application protocol (WAP) device, or the like.

[00113] Some embodiments may be used in conjunction with one or more types of wireless communication signals and/or systems following one or more wireless communication protocols, for example, radio frequency (RF), infrared (IR), frequency-division multiplexing (FDM), orthogonal FDM (OFDM), time-division multiplexing (TDM), time-division multiple access (TDM A), extended TDMA (E-TDMA), general packet radio service (GPRS), extended GPRS, code-division multiple access (CDMA), wideband CDMA (WCDMA), CDMA 2000, single-carrier CDMA, multi-carrier CDMA, multi-carrier modulation (MDM), discrete multi- tone (DMT), Bluetooth®, global positioning system (GPS), Wi-Fi, Wi-Max, ZigBee, ultra- wideband (UWB), global system for mobile communications (GSM), 2G, 2.5G, 3G, 3.5G, 4G, fifth generation (5G) mobile networks, 3 GPP, long term evolution (LTE), LTE advanced, enhanced data rates for GSM Evolution (EDGE), or the like. Other embodiments may be used in various other devices, systems, and/or networks.

[00114] Example 1 may include a device comprising memory and processing circuitry configured to: determine a space-time stream to send a signal on one or more channels, wherein the one or more channels are associated with a channel bonding factor; determine one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on the channel bonding factor; and cause to send, over the one or more channels, a signal comprising the one or more OFDM pilot tone sequences.

[00115] Example 2 may include the device of example 1 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

[00116] Example 3 may include the device of example 1 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

[00117] Example 4 may include the device of example 1 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

[00118] Example 5 may include the device of example 1 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

[00119] Example 6 may include the device of example 1 and/or some other example herein, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences may be associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

[00120] Example 7 may include the device of example 1 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix, and wherein the orthogonal space-time matrix may be a square matrix with a dimension of a total number of streams.

[00121] Example 8 may include the device of example 1 and/or some other example herein, further comprising a transceiver configured to transmit and receive wireless signals.

[00122] Example 9 may include the device of example 8 and/or some other example herein, further comprising one or more antennas coupled to the transceiver.

[00123] Example 10 may include a non-transitory computer-readable medium storing computer-executable instructions which when executed by one or more processors result in performing operations comprising: identifying, at a device, a signal received on a space-time stream associated with one or more channels, wherein the one or more channels are associated with a channel bonding factor; determining one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on a channel bonding factor; and determining a frequency offset based on the one or more OFDM pilot tone sequences.

[00124] Example 11 may include the non-transitory computer-readable medium of example 10 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

[00125] Example 12 may include the non-transitory computer-readable medium of example 10 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

[00126] Example 13 may include the non-transitory computer-readable medium of example 10 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

[00127] Example 14 may include the non-transitory computer-readable medium of example 10 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

[00128] Example 15 may include the non-transitory computer-readable medium of example 10 and/or some other example herein, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences may be associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

[00129] Example 16 may include the non-transitory computer-readable medium of example 10 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the OFDM pilot tones may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix w(i_STS , n , wherein w{i_STS , n) = = 1,2,..., N_m n = 1,2,..., N_m , wherein i_STS may

be an 1^th spatial stream of the one or more space-time streams, wherein N_STS may be a total number of the one or more space-time streams, wherein j may be an imaginary number, wherein the pilot value may be represented by PNSP(ISTS, n, k), wherein n may be an n* OFDM symbol number, wherein k may be a k^th subcarrier index, wherein PNSP(ISTS, n, k) = W(isrs, mod(« - 1, NSTS) + 1) * (2*p(n) - 1) * PNSP(ISTS, k), and wherein mod defines a modulo operation.

[00130] Example 17 may include a method comprising: determining, by one or more processors of a device, a space-time stream to send a signal on one or more channels, wherein the one or more channels are associated with a channel bonding factor; determining, by the one or more processors, one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on the channel bonding factor; and causing to send, by the one or more processors, over the one or more channels, a signal comprising the one or more OFDM pilot tone sequences.

[00131] Example 18 may include the method of example 17 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

[00132] Example 19 may include the method of example 17 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

[00133] Example 20 may include the method of example 17 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

[00134] Example 21 may include the method of example 17 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

[00135] Example 22 may include the method of example 17 and/or some other example herein, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences may be associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

[00136] Example 23 may include the method of example 17 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix, and wherein the orthogonal space-time matrix may be a square matrix with a dimension of a total number of streams. [00137] Example 24 may include the method of example 17 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix w i_STS , n , wherein

1,2,...,N _STS ; n = 1,2,..., N_STS , wherein i_STS may

[00138] Example 25 may include an apparatus comprising means for performing a method as claimed in any one of examples 17-24.

[00139] Example 26 may include a system comprising at least one memory device having programmed instruction that, in response to execution cause at least one processor to perform the method of any one of examples 17-24.

[00140] Example 27 may include a machine readable medium including code, when executed, to cause a machine to perform the method of any one of examples 17-24.

[00141] Example 28 may include the device of example 1 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix w i_STS , n) , wherein w(i_STS , n) = (ⁿ ~ ^l) \,2,...,N _STS ; n = 1,2,..., N_STS , wherein i_STS may

[00142] Example 29 may include a non-transitory computer-readable medium storing computer-executable instructions which when executed by one or more processors result in performing operations comprising: determining, by one or more processors of a device, a space-time stream to send a signal on one or more channels, wherein the one or more channels are associated with a channel bonding factor; determining, by the one or more processors, one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on the channel bonding factor; and causing to send, by the one or more processors, over the one or more channels, a signal comprising the one or more OFDM pilot tone sequences.

[00143] Example 30 may include the non-transitory computer-readable medium of example 29 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

[00144] Example 31 may include the non-transitory computer-readable medium of example 29 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

[00145] Example 32 may include the non-transitory computer-readable medium of example 29 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

[00146] Example 33 may include the non-transitory computer-readable medium of example 29 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

[00147] Example 34 may include the non-transitory computer-readable medium of example 29 and/or some other example herein, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences may be associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones. [00148] Example 35 may include the non-transitory computer-readable medium of example 29 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix, and wherein the orthogonal space-time matrix may be a square matrix with a dimension of a total number of streams.

[00149] Example 36 may include the non-transitory computer-readable medium of example 29 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix w(i_STS , n) , wherein w(i_STS , n) = 1,2,..., N_m ; n = 1,2,..., N_m , wherein i_STS may

[00150] Example 37 may include an apparatus comprising means for determining, by one or more processors of a device, a space-time stream to send a signal on one or more channels, wherein the one or more channels are associated with a channel bonding factor; means for determining, by the one or more processors, one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on the channel bonding factor; and means for causing to send, by the one or more processors, over the one or more channels, a signal comprising the one or more OFDM pilot tone sequences.

[00151] Example 38 may include the apparatus of example 37 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

[00152] Example 39 may include the apparatus of example 37 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same. [00153] Example 40 may include the apparatus of example 37 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

[00154] Example 41 may include the apparatus of example 37 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

[00155] Example 42 may include the apparatus of example 37 and/or some other example herein, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences may be associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

[00156] Example 43 may include the apparatus of example 37 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix, and wherein the orthogonal space-time matrix may be a square matrix with a dimension of a total number of streams.

[00157] Example 44 may include the apparatus of example 37 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix W (i_STS , n) , wherein e^xP - j-^- - {i_STs 1,2,..., N_m ; n = 1,2,..., N_m , wherein i_STS may be an 1^th spatial stream of the one or more space-time streams, wherein N_STS may be a total number of the one or more space-time streams, wherein j may be an imaginary number, wherein the pilot value may be represented by PNSP(ISTS, n, k), wherein n may be an n* OFDM symbol number, wherein k may be a k^th subcarrier index, wherein PNSP(ISTS, n, k) = W(isrs, mod(« - 1, NSTS) + 1) * (2*p(n) - 1) * PNSP(ISTS, k), and wherein mod defines a modulo operation. [00158] Example 45 may include a device comprising memory and processing circuitry configured to: identify, at a device, a signal received on a space-time stream associated with one or more channels, wherein the one or more channels are associated with a channel bonding factor; determine one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on a channel bonding factor; and determine a frequency offset based on the one or more OFDM pilot tone sequences.

[00159] Example 46 may include the device of example 45 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

[00160] Example 47 may include the device of example 45 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

[00161] Example 48 may include the device of example 45 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

[00162] Example 49 may include the device of example 45 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

[00163] Example 50 may include the device of example 45 and/or some other example herein, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences may be associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

[00164] Example 51 may include the device of example 45 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the OFDM pilot tones may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix w(i_STS , n) , wherein w(i_STS , n) = 1,2,..., N_m ; n = 1,2,..., N_m , wherein i_STS may

[00165] Example 52 may include the device of example 45 and/or some other example herein, further comprising a transceiver configured to transmit and receive wireless signals.

[00166] Example 53 may include the device of example 52 and/or some other example herein, further comprising one or more antennas coupled to the transceiver.

[00167] Example 54 may include a method comprising: identifying, at a device, a signal received on a space-time stream associated with one or more channels, wherein the one or more channels are associated with a channel bonding factor; determining one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on a channel bonding factor; and determining a frequency offset based on the one or more OFDM pilot tone sequences.

[00168] Example 55 may include the method of example 54 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

[00169] Example 56 may include the method of example 54 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

[00170] Example 57 may include the method of example 54 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

[00171] Example 58 may include the method of example 54 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

[00172] Example 59 may include the method of example 54 and/or some other example herein, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences may be associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

[00173] Example 60 may include the method of example 54 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the OFDM pilot tones may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix w i_STS , n) , wherein

1,2,..., N _STS ; n = 1,2,..., N_STS , wherein i_STS may

[00174] Example 61 may include an apparatus comprising means for performing a method as claimed in any one of examples 54-60.

[00175] Example 62 may include a system comprising at least one memory device having programmed instruction that, in response to execution cause at least one processor to perform the method of any one of examples 54-60.

[00176] Example 63 may include a machine readable medium including code, when executed, to cause a machine to perform the method of any one of examples 54-60.

[00177] Example 64 may include an apparatus comprising means for identifying, at a device, a signal received on a space-time stream associated with one or more channels, wherein the one or more channels are associated with a channel bonding factor; means for determining one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on a channel bonding factor; and means for determining a frequency offset based on the one or more OFDM pilot tone sequences.

[00178] Example 65 may include the apparatus of example 64 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

[00179] Example 66 may include the apparatus of example 64 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

[00180] Example 67 may include the apparatus of example 64 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

[00181] Example 68 may include the apparatus of example 64 and/or some other example herein, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

[00182] Example 69 may include the apparatus of example 64 and/or some other example herein, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences may be associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

[00183] Example 70 may include the apparatus of example 64 and/or some other example herein, wherein a pilot value of an OFDM pilot tone of the OFDM pilot tones may be based on a deterministic component of a phase shift represented by an orthogonal space-time matrix wherein

1,2,...,N _STS ; n = 1,2,..., N_STS , wherein i_STS may

[00184] Example 71 may include an apparatus comprising means for performing a method as claimed in any of the preceding examples.

[00185] Example 72 may include a machine-readable storage including machine -readable instructions, when executed, to implement a method as claimed in any preceding example.

[00186] Example 73 may include a machine-readable storage including machine -readable instructions, when executed, to implement a method or realize an apparatus as claimed in any preceding example.

[00187] Example 74 may include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of examples 1-73, or any other method or process described herein.

[00188] Example 75 may include an apparatus comprising logic, modules, and/or circuitry to perform one or more elements of a method described in or related to any of examples 1-73, or any other method or process described herein.

[00189] Example 76 may include a method, technique, or process as described in or related to any of examples 1-73, or portions or parts thereof.

[00190] Example 77 may include an apparatus comprising: one or more processors and one or more computer readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform the method, techniques, or process as described in or related to any of examples 1-73, or portions thereof.

[00191] Example 78 may include a method of communicating in a wireless network as shown and described herein.

[00192] Example 79 may include a system for providing wireless communication as shown and described herein. [00193] Example 80 may include a device for providing wireless communication as shown and described herein.

[00194] Embodiments according to the disclosure are in particular disclosed in the attached claims directed to a method, a storage medium, a device and a computer program product, wherein any feature mentioned in one claim category, e.g., method, can be claimed in another claim category, e.g., system, as well. The dependencies or references back in the attached claims are chosen for formal reasons only. However, any subject matter resulting from a deliberate reference back to any previous claims (in particular multiple dependencies) can be claimed as well, so that any combination of claims and the features thereof are disclosed and can be claimed regardless of the dependencies chosen in the attached claims. The subject- matter which can be claimed comprises not only the combinations of features as set out in the attached claims but also any other combination of features in the claims, wherein each feature mentioned in the claims can be combined with any other feature or combination of other features in the claims. Furthermore, any of the embodiments and features described or depicted herein can be claimed in a separate claim and/or in any combination with any embodiment or feature described or depicted herein or with any of the features of the attached claims.

[00195] The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[00196] Certain aspects of the disclosure are described above with reference to block and flow diagrams of systems, methods, apparatuses, and/or computer program products according to various implementations. It will be understood that one or more blocks of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and the flow diagrams, respectively, may be implemented by computer-executable program instructions. Likewise, some blocks of the block diagrams and flow diagrams may not necessarily need to be performed in the order presented, or may not necessarily need to be performed at all, according to some implementations.

[00197] These computer-executable program instructions may be loaded onto a special- purpose computer or other particular machine, a processor, or other programmable data processing apparatus to produce a particular machine, such that the instructions that execute on the computer, processor, or other programmable data processing apparatus create means for implementing one or more functions specified in the flow diagram block or blocks. These computer program instructions may also be stored in a computer-readable storage media or memory that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage media produce an article of manufacture including instruction means that implement one or more functions specified in the flow diagram block or blocks. As an example, certain implementations may provide for a computer program product, comprising a computer- readable storage medium having a computer-readable program code or program instructions implemented therein, said computer-readable program code adapted to be executed to implement one or more functions specified in the flow diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational elements or steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions that execute on the computer or other programmable apparatus provide elements or steps for implementing the functions specified in the flow diagram block or blocks.

[00198] Accordingly, blocks of the block diagrams and flow diagrams support combinations of means for performing the specified functions, combinations of elements or steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that each block of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow diagrams, may be implemented by special-purpose, hardware-based computer systems that perform the specified functions, elements or steps, or combinations of special-purpose hardware and computer instructions.

[00199] Conditional language, such as, among others, "can," "could," "might," or "may," unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations could include, while other implementations do not include, certain features, elements, and/or operations. Thus, such conditional language is not generally intended to imply that features, elements, and/or operations are in any way required for one or more implementations or that one or more implementations necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or operations are included or are to be performed in any particular implementation.

[00200] Many modifications and other implementations of the disclosure set forth herein will be apparent having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

CLAIMS What is claimed is:

1. A device, the device comprising memory and processing circuitry configured to: determine a space-time stream to send a signal on one or more channels, wherein the one or more channels are associated with a channel bonding factor;

determine one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on the channel bonding factor; and

cause to send, over the one or more channels, a signal comprising the one or more OFDM pilot tone sequences.

2. The device of claim 1, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

3. The device of claim 1, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

4. The device of claim 1, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

5. The device of claim 1, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

6. The device of claim 1 , wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences is associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

7. The device of claim 1, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences is based on a deterministic component of a phase shift represented by an orthogonal space-time matrix, and wherein the orthogonal space-time matrix is a square matrix with a dimension of a total number of streams.

8. The device of claim 1, further comprising a transceiver configured to transmit and receive wireless signals.

9. The device of claim 8, further comprising one or more antennas coupled to the transceiver.

10. A non-transitory computer-readable medium storing computer-executable instructions which when executed by one or more processors result in performing operations comprising: identifying, at a device, a signal received on a space-time stream associated with one or more channels, wherein the one or more channels are associated with a channel bonding factor;

determining one or more orthogonal frequency-division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on a channel bonding factor; and

determining a frequency offset based on the one or more OFDM pilot tone sequences.

11. The non- transitory computer-readable medium of claim 10, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

12. The non-transitory computer-readable medium of claim 10, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

13. The non- transitory computer-readable medium of claim 10, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

14. The non- transitory computer-readable medium of claim 10, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

15. The non- transitory computer-readable medium of claim 10, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences is associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

16. The non-transitory computer-readable medium of claim 10, wherein a pilot value of an OFDM pilot tone of the OFDM pilot tones is based on a deterministic component of a phase shift represented by an orthogonal space-time matrix w(i_STS , n) , wherein

2π

_; , n) -- exp - J - ^' (^'sis - !)· (" 1,2,..., N_™ - n = 1,2,..., N_™, , wherein j^" is an 1^th spatial stream of the one or more space-time streams, wherein N_STS is a total number of the one or more space-time streams, wherein j is an imaginary number, wherein the pilot value is represented by PNSP(ISTS, n, k), wherein n is an n* OFDM symbol number, wherein k is a k* subcarrier index, wherein PNSP(ISTS, n, k) = W(isrs, mod(« - 1, NSTS) + 1) * (2*p(n) - 1) * PNSP(ISTS, k), and wherein mod defines a modulo operation.

17. A method comprising:

determining, by one or more processors of a device, a space-time stream to send a signal on one or more channels, wherein the one or more channels are associated with a channel bonding factor;

determining, by the one or more processors, one or more orthogonal frequency- division multiplexing (OFDM) pilot tone sequences associated with the space-time stream, wherein the one or more OFDM pilot tone sequences are based on the channel bonding factor; and

causing to send, by the one or more processors, over the one or more channels, a signal comprising the one or more OFDM pilot tone sequences.

18. The method of claim 17, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are orthogonal to one another.

19. The method of claim 17, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein first OFDM pilot tones of the first OFDM pilot tone sequence and second OFDM pilot tones of the second OFDM pilot tone sequence have pilot tone index locations that are the same.

20. The method of claim 17, wherein the one or more OFDM pilot tone sequences comprise an OFDM pilot tone sequence, wherein OFDM pilot tones of the OFDM pilot tone sequence have pilot tone index locations that are dependent on the one or more channels and are independent of the space-time stream.

21. The method of claim 17, wherein the one or more OFDM pilot tone sequences comprise a first OFDM pilot tone sequence and a second OFDM pilot tone sequence, and wherein the first OFDM pilot tone sequence and the second OFDM pilot tone sequence are separated by a guard pilot tone sequence.

22. The method of claim 17, wherein an OFDM pilot tone sequence of the one or more OFDM pilot tone sequences is associated with a guard interval, wherein the guard interval separates a first OFDM pilot tone sequence of the one or more OFDM pilot tone sequences from a second OFDM pilot tone sequence of the one or more OFDM pilot tone sequences, and wherein the guard interval comprises four guard pilot tones.

23. The method of claim 17, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences is based on a deterministic component of a phase shift represented by an orthogonal space-time matrix, and wherein the orthogonal space-time matrix is a square matrix with a dimension of a total number of streams.

24. The method of claim 17, wherein a pilot value of an OFDM pilot tone of the one or more OFDM pilot tone sequences is based on a deterministic component of a phase shift represented by an orthogonal space-time matrix w(i_STS , n) , wherein w(i_STS , n) = = 1,2,..., N_™ - n = 1,2,..., N_™, , wherein j^" is

an 1^th spatial stream of the one or more space-time streams, wherein N_STS is a total number of the one or more space-time streams, wherein j is an imaginary number, wherein the pilot value is represented by PNSP(ISTS, n, k), wherein n is an n* OFDM symbol number, wherein k is a k* subcarrier index, wherein PNSP(ISTS, n, k) = W(isrs, mod(« - 1, NSTS) + 1) * (2*p(n) - 1) * PNSP(ISTS, k), and wherein mod defines a modulo operation.