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WO2003036835A1 - Procede d'amelioration des performances d'un transfert intercellulaire dans un systeme de communication mobile a acces multiples par repartition en code de synchronisme - Google Patents

Procede d'amelioration des performances d'un transfert intercellulaire dans un systeme de communication mobile a acces multiples par repartition en code de synchronisme Download PDF

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Publication number
WO2003036835A1
WO2003036835A1 PCT/CN2001/001457 CN0101457W WO03036835A1 WO 2003036835 A1 WO2003036835 A1 WO 2003036835A1 CN 0101457 W CN0101457 W CN 0101457W WO 03036835 A1 WO03036835 A1 WO 03036835A1
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WO
WIPO (PCT)
Prior art keywords
base station
cell
signal
delay
base stations
Prior art date
Application number
PCT/CN2001/001457
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English (en)
Chinese (zh)
Inventor
Yanshan Shi
Original Assignee
Linkair Communications, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Linkair Communications, Inc. filed Critical Linkair Communications, Inc.
Priority to PCT/CN2001/001457 priority Critical patent/WO2003036835A1/fr
Priority to CN01819003.0A priority patent/CN1226839C/zh
Publication of WO2003036835A1 publication Critical patent/WO2003036835A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
    • H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
    • H04B7/2628—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/16—Performing reselection for specific purposes
    • H04W36/18—Performing reselection for specific purposes for allowing seamless reselection, e.g. soft reselection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2201/00—Indexing scheme relating to details of transmission systems not covered by a single group of H04B3/00 - H04B13/00
    • H04B2201/69—Orthogonal indexing scheme relating to spread spectrum techniques in general
    • H04B2201/707—Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation
    • H04B2201/70702—Intercell-related aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements

Definitions

  • the invention relates to the technical field of wireless spread spectrum communication and digital mobile communication, and in particular to a method for improving handover performance in a synchronous code division multiple access (CDMA) wireless communication system.
  • CDMA synchronous code division multiple access
  • DS-SS direct sequence 'J rect Sequence Spread Spectrum
  • CDMA code division multiple access
  • CDMA is a modulation and multiple access technology based on spread-spectrum communications.
  • signals used by different users to transmit information are not distinguished by different frequencies or time slots, but by different coding sequences.
  • the receiver correlator can select a signal using a predetermined pattern among a plurality of CDMA signals. Other signals using different code patterns cannot be demodulated because they are different from the code patterns generated locally by the receiver.
  • both a base station transmitter and a mobile station transmitter use a spreading code to spread the digital information to spread the spectrum
  • the receiving device uses a local spreading code to despread the spread spectrum signal to extract useful information.
  • Synchronization is to realize that the local spreading code and the received spreading code are completely consistent in structure, frequency, and phase.
  • a CDMA system has carrier synchronization, bit synchronization, and frame synchronization in addition to general digital communication systems.
  • Spreading code synchronization is unique to it. Therefore, the synchronization problem of a spread spectrum system is more complicated than that of a general digital communication system. Getting system synchronization is not in a CDMA system Missing, and very important.
  • PN pseudo noise
  • An orthogonal code sequence In a code division multiple access (CDMA) type system, users in each communication are uniquely assigned a pseudo noise (PN) code sequence or an orthogonal code sequence. Multiple users share the same frequency band at the same time. Communicate with the system.
  • a method for distinguishing channels by using a unique code sequence is to spread a digital information signal by using a pseudo-noise (PN) code or orthogonal code allocated by the unique code sequence to form a spread-spectrum signal.
  • PN pseudo-noise
  • PN pseudo noise
  • CDMA code division multiple access
  • the communication system specified by the TIA / EIA IS-95 standard uses two pseudo noise (PN) codes, and the transmission of all forward links of each base station is determined by a certain amount.
  • PN pseudo noise
  • the same common system pseudo-noise (PN) code with unique phase in the area is spread; and each channel in the forward link is spread by the unique Walsh pseudo-noise (PN) code.
  • PN code for example, a PN code is 2 15 chips in length, and neighboring base stations will generate PN codes with different phases according to different preset chip phases. This preset chip phase is called offset, and one of its functions is to distinguish the base station.
  • CDMA code division multiple access
  • each base station is assigned a unique LA code
  • each channel is assigned a unique LS code.
  • the LS code spreads the uplink or downlink signals.
  • LA codes and LS codes are disclosed in two patents described below.
  • LA code is composed of polarized basic pulses with a normalized amplitude and width of 1. The number of basic pulses is based on the number of users required, the number of pulse compression codes that can be used, and the number of available pulse compression codes.
  • the actual factors such as the number of orthogonal pulse compression codes, the number of orthogonal frequencies that can be used, the system bandwidth, and the maximum signal transmission rate of the system are determined.
  • the intervals of the basic pulses on the time coordinate are different and different. Equal and different pulse position and pulse polarity arrangement coding. Taking the above design, it provides a concise and fast design method for the spread spectrum address code for the spread spectrum technology and digital multiple access technology.
  • the characteristics of this LA code are: first: the main peaks of the autocorrelation function are equal to the number of basic pulses, and also the number of orthogonal codewords in the code group; second: the subpeaks of the autocorrelation and crosscorrelation functions are only +1 Three possible values, -1 and 0.
  • the LA code can be used to identify different cells.
  • a patent (PCT / CN00 / 00028) entitled "A Spread Spectrum Multiple Address Coding Method with Zero Correlation Window” mentions a CDMA scheme with zero correlation window.
  • a spread-spectrum multi-address code which is abbreviated as LS code.
  • the auto-correlation and cross-correlation functions of the newly generated spread spectrum multi-address code can form a "zero correlation window" near the origin, and the "zero correlation” In the window, the multiple access interference (MAI) and the inter-symbol interference (ISI) are zero. Therefore, the code division channel codes selected within a cell have unique correlation characteristics with each other. Correlation characteristics between channel codes Not only has complete orthogonality, but its offset-related characteristics are also fixed within a certain offset interval (0); therefore, the CDMA scheme is very suitable for wireless communication systems with multipath effects. .
  • LAS-CDMA does not use continuous pilots to assist mobile stations to obtain synchronization.
  • the synchronization auxiliary channels (which may be pilot channels, broadcast channels, or synchronization channels) and service data channels may be time-division structures and synchronized.
  • the spreading code sequence of the auxiliary channel may be a set of LS codes.
  • base stations are distinguished according to the uniqueness of the LA code, and
  • the uniqueness distinguishing channel may distinguish the synchronization auxiliary channel of the base station according to the uniqueness of the synchronization auxiliary channel orthogonal code (such as LS code).
  • the synchronization of the spreading code is divided into two steps.
  • One is capturing, that is, coarsely adjusting the frequency and phase of the local spreading code so that the phase difference between the local spreading code and the receiving spreading code is less than one symbol width Tc.
  • the artificial noise PN code sequence or orthogonal code sequence generated by the transmitting end and the receiving end is roughly aligned in time and accurate to a gap of ch ip.
  • the second is tracking, which automatically adjusts the phase of the local spreading code. It is precisely synchronized with the frequency and phase of the received spreading code.
  • the PN code generator On the receiving side, when the mobile station's power switch is turned on, the PN code generator generates a PN code sequence that moves ch i p phase gradually from zero offset. The receiver will monitor the correlation between these PN code sequences and the PN code in the synchronization assistance signal sent by the base station in order to search for the PN offset used by the base station. Once the PN offset used by a base station is searched, the mobile station will receive the synchronization channel and obtain synchronization information. If communication is required at this time, the mobile station will select the base station with the strongest signal among all the searched base station signals to make an access attempt, and will maintain synchronization with the base station.
  • the following scheme is adopted. After the mobile station power switch is turned on, different orthogonal code sequences (such as LS codes) are generated by the orthogonal code generator, and they are moved within a certain time domain to monitor their relationship with the base station. Correlation between orthogonal codes (such as LS codes) used by the transmitted signal. Once the code sequence used by a base station signal is the same as the code sequence generated locally by the mobile station and aligned in time, the receiver will despread the synchronization information in the signal. If communication with the base station is required thereafter, the mobile station will also select the base station with the strongest signal among all the searched base station signals, and will maintain synchronization with the base station.
  • orthogonal code sequences such as LS codes
  • the length of time to obtain synchronization and the probability of correctly obtaining synchronization are the criteria for determining synchronization performance. Standard. Due to the importance of obtaining synchronization, in this field, many schemes for detecting and determining base station signals have been proposed and applied.
  • the mobile station After the synchronization with a certain base station has been obtained, the mobile station must continue to monitor the signals of other base stations, so as to switch to other base stations when the signal strength of the serving base station is insufficient and the signals of other base stations are strong enough.
  • CDMA code division multiple access
  • TDMA time division multiple access
  • the mobile station knows from the current base station the orthogonal code (such as the LS code) used by the neighboring base station to synchronize the auxiliary channel, but Because the time difference between the time when the base station signal arrives at the mobile station and the current base station signal is uncertain, the mobile station should search for signals from neighboring base stations within a certain time or phase difference range.
  • orthogonal code such as the LS code
  • the system is required to maintain synchronization on both the forward and reverse links, that is, the signals sent by mobile stations in different positions in the cell must reach the base station synchronously, and the signals of each code channel
  • the arrival time difference cannot exceed a certain range (for LAS-CDMA systems, the range is the interference-free window width), otherwise the base station may not be able to correctly despread or be subject to greater interference.
  • the distance between the mobile station and two neighboring base stations is almost equal and the base stations are synchronized (the clocks of the base stations are generally synchronized), the signals sent by the mobile stations will reach the two base stations synchronously. At the same time, it is equivalent to meeting the requirement of reverse synchronization with two base stations at the same time, so that soft handover may be realized.
  • the radius of the cells covered by each base station is not always equal.
  • the distance from the two base stations is different.
  • the possible time difference between the signals of the two base stations arriving at the mobile station is greater than that at the cell boundary with the same radius. The possible time difference between signal arrivals is large; and the more the two cell radii differ, the larger the The greater the time difference range.
  • the mobile station in the handover state wants to receive signals from neighboring base stations in macro diversity, it is bound to increase the delay between each Finger in the RAKE receiver to realize the reception of signals from neighboring base stations.
  • the purpose of the present invention is to provide a new synchronization delay setting method for a synchronous code division multiple access (CDMA) wireless spread spectrum communication system, so as to solve and overcome the defects and shortcomings existing in the prior art solutions.
  • CDMA synchronous code division multiple access
  • the synchronization delay setting method of the present invention in a downlink, by setting the synchronization delay of a transmission signal between adjacent base stations, the boundary of the cell where the adjacent base station is located, regardless of whether the cell radius is Similarly, the handover area coincides with the search area where the mobile station acquires the base station signal. At the same time, when a mobile station in this area receives signals from adjacent base stations at the same time, the delay between each F i nger in the Rake receiver does not depend on the phase. The neighbour cell radius is different.
  • the synchronization delay setting method of the present invention in the uplink, by setting the synchronization delay of despreading a received signal between adjacent base stations, the boundary of the cell where the adjacent base station is located, regardless of whether the cell radius is the same Mobile stations can maintain reverse synchronization with all neighboring base stations under certain conditions, so that the realizable area of soft handover is located exactly at the border of the cell, and in mobile communications that require reverse synchronization In the system, soft handover is implemented.
  • the base station is reached during operation, so that the signals sent by the mobile stations at the cell borders arrive at the respective base stations when they are despread separately.
  • a synchronization delay setting method for a synchronous code division multiple access (CDMA) spread-spectrum communication system In downlink, by setting the synchronization delay of a transmission signal between adjacent base stations, the cell in which the adjacent base station is located is set. At the boundary of the cell, regardless of whether the cell radius is the same, the handover area coincides with the search area where the mobile station acquires the base station signal, and when the mobile station in the area receives the signal from the adjacent base station at the same time, the delay between the receivers is not The radius of neighboring cells is different.
  • the synchronization delay setting method provided by the present invention determines the transmission or despreading delay amount of each adjacent base station according to the difference in cell radius between each adjacent cell. Specifically, in In the downlink, adjust the transmission delay of the signals transmitted by each neighboring base station, the base stations in the large radius cell transmit the signal in advance, and the base stations in the small radius cell lag the transmission; in the uplink, adjust the despread signal of each neighboring base station.
  • the delay amount is extended by the base stations of the large-radius cell, and the base stations of the small-radius cell are despread in advance. That is, the time when all mobile stations in the cell send uplink data is based on the transmission time of the mobile station at the cell boundary.
  • the interval is different and the transmission is delayed accordingly.
  • the base station After the base station completes the deblocking, the base station reversely adjusts the corresponding despreading delay amount and then communicates with the higher-level network to restore the synchronization between the base station and the higher-level network.
  • the mobile station obtains the synchronization search time of the neighboring base stations, and the time or phase delay between each Finger when the Rake receiver receives the signals of the neighboring base stations in diversity, not because of the distance between the mobile station and the neighboring base stations.
  • the mobile station at the boundary is kept in reverse synchronization with multiple base stations under certain conditions, thereby improving the code synchronization performance and possible soft handover in the two-way synchronization wireless system.
  • Figure 1 shows the relationship between the area of the cell with the same radius (take 2 cells as an example), the area of small search range, and the two-way synchronous soft handover implementation area and the cell boundary.
  • Figure 2 shows the relationship between the small search area area and the two-way synchronous soft handover implementation area at the cell boundaries with different radii (take 2 cells as an example) and the cell boundary.
  • Figure 3 shows the relationship between the small search area area, the two-way synchronized soft handover implementation area, and the cell boundary at the cell boundaries with different radii (taking 2 cells as an example) according to the method of the present invention.
  • Figure 4 shows the relationship between the small search area area, the two-way synchronized soft handover implementation area and the cell boundary at the cell boundaries with different radii (taking 3 cells as an example) according to the method of the present invention.
  • FIG. 5 is a schematic diagram of setting a synchronization delay for transmitting or despreading a base station according to the method of the present invention (taking 4 cells as an example).
  • Mode of Carrying Out the Invention It can be known from the prior art that if two neighboring base stations transmit signals at the same time, the signals will reach the area with a smaller time difference from the two base stations with a smaller time difference. At this time, the mobile station can search for signals of adjacent base stations and implement handover within a small uncertainty range. This search range is referred to as a signal search area for handover in the present invention, and corresponds to the handover implementation area. . In the present invention, the search range in which the mobile station can search for signals of adjacent base stations within a small range is referred to as a small search range, and the area corresponding to the range is called a small search range area.
  • the radii are respectively set to 1 2
  • the base stations are set to 8! And B 2 respectively
  • the distance between the two base stations is set to D 12
  • a mobile station M is set somewhere between the two base stations and the distances to the base stations ⁇ and B 2 are ⁇ and r 2 respectively.
  • the clocks of the two base stations are synchronized, that is, the two base stations start to send their respective frame signals at the same time, then near the center line M (that is, the vertical line and the boundary line) that is equal to the two base stations, (the vicinity of this center line M is simultaneously It is also the boundary of the cell.)
  • the time difference between the frame header signals sent by the two base stations near the center line is small.
  • a mobile station located near the center line M can capture signals of neighboring base stations with a small search range.
  • the signals transmitted by the mobile station near the center line M with the same distance from the two base stations will reach the two base stations at almost the same time.
  • the mobile station can achieve Reverse synchronization of two base stations.
  • the small-area search area, the handover implementation area, and the cell boundary overlap.
  • E is a small-area search area, and a central area and a soft handover realizable area in each synchronization system.
  • S is a boundary area and a switching area.
  • the mobile station must increase the search range to capture the signals of neighboring base stations, which is equivalent to expanding the implementation area of the handover and covering the cell boundary.
  • each Finger in the Rake receiver When receiving macro-diversity signals from multiple base stations, each Finger in the Rake receiver The time or phase delay between them is also increased; if the base stations despread at the same time, the signals transmitted by these mobile stations cannot arrive at the same time when the two base stations despread, and it is difficult to achieve reverse synchronization with multiple base stations in a two-way synchronization system.
  • the time when the signal transmitted by the mobile station arrives at the base station B 2 relative to the base station is 2, where c is the speed of light, the unit is meter / second, the unit of rnr 2 is meter, and the unit of t i2 and tu is second.
  • any time difference t 12 or ⁇ will correspond to a set of hyperbola between two base stations.
  • t 12 ⁇ Q or, 2 > it corresponds to a curve near the base station ⁇ ;
  • t 12 ⁇ G or 12 ⁇ 0 it corresponds to a curve near the base station B 2 .
  • each ch ip runs at a speed equivalent to about 244 meters.
  • Each of the above curves corresponds to a zone band of about 244 meters wide. A width will vary depending on the chip rate. Since ⁇ 1 2 , the boundary between the two cells should be close to the base station and because the coverage areas of the two base stations overlap, it is defined on the connection between the two base stations. The distance between the boundary between the two cells and the base station is
  • the purpose of the present invention is to make the frame header signals sent by two base stations reach M at the same time.
  • the method proposed by the present invention is: On the downlink, the distance is long. The frame header signal of the base station is sent first, and the frame header signal of the near base station is sent later; in the uplink, the despread signal timing of the far base station is required to lag, and the despread signal timing of the near base station is advanced.
  • the effect is This is achieved by setting the standard transmission position of the mobile station in the cell by the base station, that is, setting the standard transmission position to the boundary of the cell, so that the mobile station with a small distance from the base station delays the transmission of uplink data accordingly, so that its signal and the movement at the boundary
  • the signals transmitted by the stations arrive at the base station of the cell synchronously. Because the radius of each cell is different, the boundary distance is different from the distance between adjacent base stations, thereby causing a delay between the despreading times of the uplink data by the adjacent base stations.
  • the base station B 2 that is far away should correspond to the base station B with a delay of 2 seconds to despread the signal. Then the despreading delay of B 2 relative to the received signal is
  • FIG. 3 is a schematic diagram adjusted by the foregoing method. After the adjustment, the small-area search area, the cell boundary, and the handover area overlap at the boundary of two cells with different radii.
  • the following manner can be used to specifically calculate the delay amount that each base station should adopt.
  • one of the cells is arbitrarily selected as a standard cell, and the base station is set to B Q and the radius is R.
  • the radius of any cell is taken as the standard radius, and the time when the base station transmits or despreads the signal is the standard transmission and standard despread time, respectively.
  • the standard transmission time delay is the transmission delay calculated by dividing the difference between the cell radius and the standard radius by the inverse of the quotient of the speed of light; and the despread time of the base station is delayed by the difference between the cell radius and the standard radius divided by the standard despread time
  • the despreading delay calculated by the quotient of the speed of light, the handover realization area, the small-area search area, and the cell boundary can coincide at the cell boundary at all cell boundaries, that is, the result that all cell boundaries are exactly the area where the handover is performed .
  • CDMA Code division multiple access
  • each base station transmits signals and despread signals at different times according to the coverage radius of the corresponding cell, when each base station communicates with its superior network equipment, such as a switch, the delay amount must be adjusted back accordingly to meet the base station location. Requirements for synchronization in communication network systems.
  • the base station In order to synchronize with the switch, the base station should adjust the communication delay with the switch according to the inverse of the despread delay. Let the despreading delay of the base station Bi be relative to the standard base station 8. Yes. While B. The moment when the despread data is formed is e. Send to the switch at time e D + T, where T is the delay between sending data and forming data. Then the data formation time of the base station B ; is e. +. In order to send data to the switch at time e Q + T to synchronize with the base station B Q , the data transmission and formation delay of the base station should be 4), that is, the delay amount equivalent to B Q is ⁇ . .
  • each mobile station in the cell is required to transmit signals to the base station synchronously regardless of the distance from the base station, that is, reverse synchronization is required.
  • the base station simultaneously performs despreading of the received signal, it is also possible that only signals sent by mobile stations in areas with a small distance difference from neighboring base stations can reach these simultaneously when despreading is performed by multiple base stations.
  • the base station implements reverse synchronization with multiple base stations, and when adjacent base stations use the same LA code, soft handover can be achieved.
  • the mobile station cannot meet the requirement of reverse synchronization with multiple base stations simultaneously.
  • the time of despreading of the base station of the large radius cell should be delayed, while that of the base station of the small radius cell
  • the timing of despreading is advanced, so that when the signals of the mobile station are despread separately at each base station, they just reach the base station, which is equivalent to setting the standard transmission position of the cell mobile station to the boundary of the cell, and the The implementation area just covers the cell boundary. In this way, it becomes possible for the two-way synchronization system to implement soft handover at cell boundaries with different radii.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne un procédé de retard temporel par synchronisme d'un signal de station de base émettant ou désétalant un système de communication mobile numérique et de communication à spectres étalés radiaux à accès multiples par répartition en code. L'invention peut assurer un retard temporel relatif à un signal transmis, rendant possible à des signaux provenant d'une station de base voisine d'atteindre la limite de leur cellule voisine dans une différence temporelle très courte, indépendamment du rayon des deux cellules. Elle peut également assurer un retard temporel relatif à un signal de désétalement rendant possible aux signaux dans des systèmes synchrones bidirectionnels, transmis à partir d'une station mobile dans une cellule limite, la synchronisation inverse avec des signaux provenant de multiples stations de base voisines dans certaines conditions. Le procédé permet aux systèmes synchrones bidirectionnels de réaliser un transfert intercellulaire sans ambages et facile, sans pour autant augmenter la fourchette de recherche de la station mobile de synchronisation de code comme résultat de la différence de rayon des deux cellules voisines.
PCT/CN2001/001457 2001-09-27 2001-09-27 Procede d'amelioration des performances d'un transfert intercellulaire dans un systeme de communication mobile a acces multiples par repartition en code de synchronisme WO2003036835A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/CN2001/001457 WO2003036835A1 (fr) 2001-09-27 2001-09-27 Procede d'amelioration des performances d'un transfert intercellulaire dans un systeme de communication mobile a acces multiples par repartition en code de synchronisme
CN01819003.0A CN1226839C (zh) 2001-09-27 2001-09-27 一种在同步码分多址移动通信系统中提高切换性能的方法

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PCT/CN2001/001457 WO2003036835A1 (fr) 2001-09-27 2001-09-27 Procede d'amelioration des performances d'un transfert intercellulaire dans un systeme de communication mobile a acces multiples par repartition en code de synchronisme

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WO2006111075A1 (fr) * 2005-04-21 2006-10-26 Huawei Technologies Co., Ltd. Procede de limitation de l'utilisation du service d'itinerance
CN102124776A (zh) * 2009-11-03 2011-07-13 高通股份有限公司 Td-scdma系统中在接力切换期间继续进行hspa的方法和装置
US9425517B2 (en) 2011-07-04 2016-08-23 Saint-Gobain Glass France Method for producing a pane having an electrical connection element

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CN100376089C (zh) * 2005-06-03 2008-03-19 上海原动力通信科技有限公司 时隙码分多址系统多小区联合检测方法
CN100409588C (zh) * 2005-06-03 2008-08-06 上海原动力通信科技有限公司 时隙码分多址系统多小区联合检测方法
JP4569768B2 (ja) * 2005-06-17 2010-10-27 日本電気株式会社 移動通信システム、移動端末及び移動端末送信スケジューリング方法
CN105356995B (zh) * 2015-11-24 2018-06-26 山东胜开电子科技有限公司 一种同步码双向恢复方法及电路

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WO2000064091A2 (fr) * 1999-04-16 2000-10-26 Siemens Information And Communication Networks S.P.A. Procede et systeme servant a synchroniser des stations de base dans des reseaux de telecommunication numeriques

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WO2006111075A1 (fr) * 2005-04-21 2006-10-26 Huawei Technologies Co., Ltd. Procede de limitation de l'utilisation du service d'itinerance
CN102124776A (zh) * 2009-11-03 2011-07-13 高通股份有限公司 Td-scdma系统中在接力切换期间继续进行hspa的方法和装置
US9425517B2 (en) 2011-07-04 2016-08-23 Saint-Gobain Glass France Method for producing a pane having an electrical connection element

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