+

WO2001091322A1 - Procede d'adaptation de liaisons et evaluation de la qualite dans un systeme radio cellulaire - Google Patents

Procede d'adaptation de liaisons et evaluation de la qualite dans un systeme radio cellulaire Download PDF

Info

Publication number
WO2001091322A1
WO2001091322A1 PCT/SE2001/000812 SE0100812W WO0191322A1 WO 2001091322 A1 WO2001091322 A1 WO 2001091322A1 SE 0100812 W SE0100812 W SE 0100812W WO 0191322 A1 WO0191322 A1 WO 0191322A1
Authority
WO
WIPO (PCT)
Prior art keywords
transmission
channel quality
pilot
time period
future time
Prior art date
Application number
PCT/SE2001/000812
Other languages
English (en)
Inventor
Erik Dahlman
Stefan Parkvall
Original Assignee
Telefonaktiebolaget Lm Ericsson
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 Telefonaktiebolaget Lm Ericsson filed Critical Telefonaktiebolaget Lm Ericsson
Priority to AU2001247037A priority Critical patent/AU2001247037A1/en
Publication of WO2001091322A1 publication Critical patent/WO2001091322A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
    • H04W52/04—Transmission power control [TPC]
    • H04W52/18—TPC being performed according to specific parameters
    • H04W52/22—TPC being performed according to specific parameters taking into account previous information or commands
    • H04W52/223—TPC being performed according to specific parameters taking into account previous information or commands predicting future states of the transmission
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
    • H04W52/04—Transmission power control [TPC]
    • H04W52/30—Transmission power control [TPC] using constraints in the total amount of available transmission power
    • H04W52/32—TPC of broadcast or control channels
    • H04W52/325—Power control of control or pilot channels

Definitions

  • the present invention generally concerns a cellular radio system, and more specifically link adaptation, channel quality estimation as well as transmission of pilots in such a system.
  • link adaptation the transmission parameters used for communication on the link are adapted to the channel conditions of the link in order to provide as high a data rate as possible.
  • the modulation and coding scheme used by the access point for communication with the user equipment can be varied and is typically selected in dependence on the downlink channel quality.
  • the modulation and coding scheme can be optimized to the channel conditions, leading to a considerable improvement of the downlink channel throughput (normally expressed in terms of bits/s). This is also known as an Adaptive
  • AMCS Modulation and Coding Scheme
  • MCS modulation and coding scheme
  • the downlink channel quality is typically expressed as the downlink signal-to-interference ratio or some other related measure.
  • the channel-quality estimate is typically derived by the user equipment some frames in advance, and reported to the network using uplink signaling.
  • the network selects a suitable MCS to be used for downlink transmission to this user equipment in a given future frame.
  • the user equipment itself decides on a suitable MCS and reports the selected MCS to the network for subsequent use in the downlink transmission to the user equipment.
  • a common way of providing the user equipment with a means to estimate the channel quality is to have each access point periodically transmit a predetermined chip sequence, also known as a pilot, for reception by the user equipment. During pilot transmission, there is no other transmission from the access point. Neighboring access points generally use different chip sequences for the pilot or different shifts of the same chip sequence, and the pilot can either be transmitted once per frame or several times per frame.
  • HDR High Data Rate
  • Fig. 1 is a schematic timing diagram illustrating an example of the transmissions of time-multiplexed pilots and possible data from a plurality of access points in a cellular system during a number of consecutive frames.
  • Each transmitted frame comprises a pilot, indicated in black, followed by possible payload data.
  • the example of Fig. 1 is representative of a cellular system with tight inter-cell synchronization, and therefore all access points AP-1 to AP-N are able to transmit the frames including the pilots so that they are substantially time aligned to each other. Ignoring propagation delays, it can be assumed that the overall signal received by a given user equipment will be the sum of the pilot signals from all the access points AP-1 to AP-N attenuated by the respective propagation losses.
  • the user equipment can estimate the signal-to- interference ratio (SIR) during the pilot part of frame n for the link between the user equipment and the access point under consideration. This estimate can then be used for selecting the modulation and coding scheme (MCS) for the transmission of data by the access point in a future frame such as frame n+1 or frame n+2.
  • SIR signal-to- interference ratio
  • a problem with the prior art technique outlined above is that the estimated interference will be the worst-case interference corresponding to the case when all access points are actively transmitting at full power. This may lead to the selection of a non-optimal MCS, and hence inefficient link adaptation.
  • the present invention overcomes these and other drawbacks of the prior art arrangements.
  • the present invention is based on the recognition that conventional pilot-based channel quality estimation does not take into account the future transmission activity of neighboring access points or transmitters, and that this may lead to inaccurate channel quality estimation as well as inefficient link adaptation.
  • Channel quality estimation is based both on what is transmitted on the channel for subsequent measurement as well as the actual measurement, and the present invention focuses on the transmission part of the overall channel-quality estimation mechanism.
  • the transmission conditions during the pilot-based estimation or prediction of channel quality can be correlated to the transmission conditions of the future frame, or other time period, in which the corresponding modulation and coding scheme is to be used.
  • more accurate predictions of the channel quality can be made so that optimal or near-optimal modulation and coding schemes can be selected during link adaptation. This in turn results in increased data rates and higher data throughput.
  • the pilot transmission power is based on the amount of data to be transmitted in the future frame. The transmission power is normally zero when the data queues are empty and no data is to be transmitted, and non-zero only when data is to be transmitted.
  • the channel quality is conveniently represented by the signal-to-interference ratio of the link, or some other related measure.
  • the channel quality is typically estimated by the user equipment a predetermined number of frames in advance based on the received pilots, and a representation of the channel quality estimate is reported by uplink signaling so that the access point transmitter can select a suitable modulation and coding scheme for downlink transmission in a given future frame.
  • the invention offers at least the following advantages: More accurate prediction of channel quality; Efficient link adaptation; and Increased data rates.
  • Fig. 1 is a schematic timing diagram illustrating an example of the transmissions of time-multiplexed pilots and possible data from a plurality of access points in a conventional cellular system during a number of consecutive frames;
  • Fig. 2 is a schematic overview of an exemplary communication system in which the present invention may be used;
  • Fig. 3 is a schematic timing diagram illustrating an example of the transmissions of time-multiplexed pilots and data from a plurality of access points in a conventional cellular system
  • Fig. 4 is a schematic timing diagram illustrating an example of the transmissions of time-multiplexed pilots and data from a plurality of access points according to a first embodiment of the invention
  • Fig. 5 is a schematic timing diagram illustrating an example of the transmission of time-multiplexed pilots and data from a given access point according to a second preferred embodiment of the invention
  • Fig. 6 is a schematic block diagram of a receiver which can be used by the present invention.
  • Fig. 7 is a schematic block diagram of a transmitter according to a preferred embodiment of the invention.
  • FIG. 2 is a schematic overview of an exemplary communication system in which the present invention may be used.
  • the communication system 10 comprises a number of remote mobile terminals 1-1 to 1-3 which are connected by radio links to a number of access points 2-1 to 2-3.
  • the access points 2-1 to 2-3 are normally representative of sectors or cells served by base stations or equivalents.
  • the access points of these base stations are connected to a communication network 3, which connects different access points to each other, and connects access points to the core network for communication with other parts of the communication network.
  • Fig. 3 is a schematic timing diagram illustrating an example of the transmissions of time-multiplexed pilots and data from a plurality of access points in a conventional cellular system during a number of consecutive frames.
  • the user equipment can estimate the channel quality of a link between the user equipment and a specific access point as the signal-to-interference ratio (SIR) of the link during the pilot part of a given frame n by measuring the signal strength of the pilot from the access point as well as the total interference from all the other access points during the pilot part of frame n. This estimate is then used for selecting the modulation and/or coding scheme (MCS) for the transmission of payload data by the access point in a future frame; for example frame n+1, assuming a one-frame delay between the SIR estimation and the use of the selected MCS. This is indicated in Fig. 3 for access point AP-N by the line extending from the pilot part of frame n to the data part of frame n+1.
  • SIR signal-to-interference ratio
  • the estimated interference will always be the worst- case interference corresponding to the case when all access points are actively transmitting at full power, and no account is taken to the possible inactivity (no transmission of data) of neighboring access points during the future frame in which the selected MCS is to be used.
  • the interference measurement takes the interference from all pilots, including also the pilot of access point AP-2, into account.
  • the access point AP-2 will not transmit any data, e.g. due to empty data queues. This means that AP-2 will not contribute to the interference during the payload data part of frame n+1, which is the frame in which the MCS that is selected based on the interference measurements in frame n will actually be used.
  • Fig. 4 is a schematic timing diagram illustrating an example of the transmissions of time-multiplexed pilots and data from a plurality of access points according to a first embodiment of the invention.
  • measurements during the pilot part of a frame such as frame n, are used for estimating the SIR or some other measure representative of the channel quality of a link, and for subsequently selecting a suitable MCS for frame n+1, assuming a one-frame delay between SIR estimation to MCS selection.
  • the invention proposes an active correlation of the transmission conditions during the pilot-based estimation of channel quality to the transmission conditions during the future frame in which the corresponding modulation and coding scheme is to be used. This is achieved by controlling the transmission of pilots based on the future transmission activity of the access points so that the pilots, indicated by black in Fig. 4, are transmitted in a given frame n only when there will actually be transmission of data by the corresponding access points in the future frame n+1. This means that the user equipment measuring interference during the pilot part of frame n, will only receive interference from those access points that will be actively transmitting data during frame n+1. An efficient way of determining whether or not there will be any transmission of data in frame n+1 is to investigate the corresponding data queue.
  • interference measurements during frame n+1 will not include any pilots from access points AP-3 and AP-N since these access points will not be active during the data part of frame n+2 and thus not cause any interference in that frame.
  • interference measurements during frame n+2 will not include any pilots from access point AP-2, since that access point will not transmit any data in frame n+ 3.
  • the transmission power of a pilot is controlled based on the expected transmission activity of the corresponding access point AP-K during a given future frame. This means that a pilot need not be transmitted with the maximum output power of the corresponding access point, but rather with a power equal to the expected power for transmission of data in the given future frame.
  • An efficient way of determining the expected power for transmission of payload data during a future frame is to investigate the data queue of the corresponding access point, as will be explained later on.
  • the pilots can be regarded as activity-indicating pilots since the pilot transmission power is based on the future transmission activity of the corresponding access point.
  • Fig. 6 is a schematic block diagram of a receiver which can be used by the present invention.
  • the receiver 20 is normally provided in user equipment such as a mobile terminal or equivalent, and comprises a signal receiver element 21, a switch element 22, an interference measuring unit 23, a pilot signal strength measuring unit 24, a channel quality estimator 25 and a MCS selector 26.
  • the receiver also comprises a demodulator 27 and a decoder 28 for demodulating and decoding a data signal modulated and coded according to a previously selected MCS and transmitted to the receiver by a base station access point.
  • the switch element 22 is closed during the pilot periods, and based on the pilots received by the signal receiver element 21 from the different access points, the user equipment determines an estimate of the channel quality of the link between the user equipment and a given access point.
  • the channel quality is typically estimated as the signal-to-interference ratio (SIR) of the link.
  • SIR signal-to-interference ratio
  • a promising way of measuring the interference is to reserve a channelization code as an "interference-measurement code", which is never used for information transfer.
  • the user equipment can then obtain an interference estimate by means of a de-spreading process using the reserved channelization code.
  • the reserved code used in the de-spreading process can be considered as a virtual code that is orthogonal to the pilot transmitted by the given downlink access point.
  • the signal strength estimate "S” from the pilot signal strength measuring unit 24 and the interference estimate “I” from the interference measuring unit 23 are combined in the channel quality estimator 25 to generate a SIR estimate, which is transferred to the MCS selector 26.
  • the MCS selector 26 decides on a suitable MCS based on the generated SIR estimate, and transmits the selected MCS to the relevant access point on the uplink.
  • the SIR estimate itself or any suitable representation thereof it is equally possible to transmit the SIR estimate itself or any suitable representation thereof to the access point, and have the network decide which MCS to use for downlink transmission. For example, it is possible to map the estimated SIR into one of a number of data rate modes, and feed this channel state information back to the access point via the uplink.
  • the user equipment itself decides on a suitable MCS and transmits the selected MCS to the relevant access point on the uplink.
  • the present example generally corresponds to the existing HDR system.
  • a possible set of modulations schemes to choose from could for example be ⁇ QPSK, 8PSK, 16QAM ⁇ , and a possible set of coding schemes could for example be turbo codes with coding rates ⁇ 1/4, 3/8, 1/2 ⁇ .
  • a specific modulation and/or coding scheme is selected depending on estimated channel quality, typically the estimated signal-to- interference ratio (SIR). If the channel quality is poor, a lower order modulation, such as QPSK, may be selected together with a coding scheme of relatively low coding rate. With improved channel quality comes the possibility to use a higher order modulation, such as 8PSK or even 16QAM, and higher coding rates. In general, higher order modulation and higher coding rates give higher data transfer rates than lower order modulation and lower coding rates.
  • SIR estimated signal-to- interference ratio
  • the data rate of link employing a modulation and coding scheme based on 16QAM and a coding rate of 1/2 is normally 4 times higher than that of a link employing a modulation and coding scheme based on QPSK and a coding rate of 1/4, provided all other relevant link parameters are the same for the two cases.
  • modulation and coding schemes are only illustrative examples of schemes that can be used by the invention.
  • any suitable MCS known in the art can be selected for transmission of data.
  • Fig. 7 is a schematic block diagram of a transmitter according to a preferred embodiment of the invention.
  • the transmitter 30 is normally provided in a base station or equivalent, and comprises a data buffer 31, a channel coder 32, a modulator 33, a pilot generator 34, a pilot output power amplifier 35, a multiplexor 36, a transmission element 37 as well as a control unit 38.
  • the control unit 38 determines the output power of the pilot in a current frame by controlling the gain of the pilot output power amplifier 35.
  • the gain factor is preferably normalized to the interval of 0-1 so that the pilot can be transmitted at any power between zero power and full power.
  • control unit 38 is responsive to the MCS selection made by user equipment communicating with the access point, and controls the modulation and coding scheme used by the channel coder 32 and the modulator 33 accordingly.
  • the control unit 38 also controls the multiplexor 36 that switches between the pilot input and the data input.
  • the multiplexor 36 forwards the pilot sequence, which is appropriately amplified by the amplifier 35, to the transmission element 37 for transmission to the user equipment.
  • the multiplexor 36 forwards channel coded and modulated pay load data as input to the transmission element 37 for transmission to the user equipment.
  • each and every access point in the radio system is configured so that it is capable of controlling the pilot transmission power based on the transmission activity expected in a predetermined future time period.
  • the prediction of channel quality is generally improved compared to the prior art even though the inventive pilot transmission power control is exercised in only a single access point.
  • pilot measurements made during frame n could be used to select the MCS in frame n+2, corresponding to a delay of two frames between SIR estimation and MCS selection.
  • the examples shown may have indicated that the activity-indicating pilot has replaced the conventional pilot, it is equally feasible to have a system in which the activity-indicating pilot co-exists with a second pilot.
  • the second pilot may be used for other purposes such as cell search and phase estimation.

Landscapes

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

Abstract

L'invention concerne la reconnaissance du fait qu'une évaluation pilote traditionnelle de la qualité d'un canal ne tient pas compte de l'activité de transmission future des points d'accès voisins, et que cela peut déboucher sur une évaluation erronée de la qualité du canal ainsi que sur une adaptation de liaison inefficace. La régulation de la puissance de transmission des pilotes en fonction de l'activité future de transmission de données permet de corréler les conditions de transmission pendant l'évaluation pilote de la qualité du canal (par exemple trame n) aux conditions de transmission de la trame future (par exemple trame n+1), dans laquelle la modulation correspondante et le schéma de codage doivent être utilisés. Ainsi, des prédictions plus précises de la qualité du canal peuvent être effectuées, de telle manière que la modulation optimale ou quasi-optimale et les schémas de codage peuvent être sélectionnés pendant l'adaptation de liaison. Ceci débouche alors sur une augmentation des taux de données de liaison.
PCT/SE2001/000812 2000-05-23 2001-04-11 Procede d'adaptation de liaisons et evaluation de la qualite dans un systeme radio cellulaire WO2001091322A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2001247037A AU2001247037A1 (en) 2000-05-23 2001-04-11 Link adaptation method and quality estimation in a cellular radio system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE0001918-2 2000-05-23
SE0001918A SE0001918L (sv) 2000-05-23 2000-05-23 Aktivitetsindikerande pilot

Publications (1)

Publication Number Publication Date
WO2001091322A1 true WO2001091322A1 (fr) 2001-11-29

Family

ID=20279799

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE2001/000812 WO2001091322A1 (fr) 2000-05-23 2001-04-11 Procede d'adaptation de liaisons et evaluation de la qualite dans un systeme radio cellulaire

Country Status (3)

Country Link
AU (1) AU2001247037A1 (fr)
SE (1) SE0001918L (fr)
WO (1) WO2001091322A1 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004066520A1 (fr) * 2003-01-16 2004-08-05 Qualcomm Incorporated Commande de la marge de puissance dans un systeme de communication de donnees
EP1513356A2 (fr) 2003-09-02 2005-03-09 Sony Ericsson Mobile Communications Japan, Inc. Procédé et dispositif de radiocommunication
WO2005109673A1 (fr) * 2004-05-11 2005-11-17 Koninklijke Philips Electronics N.V. Procede et dispositif de reglage de puissance avec prevision des perturbations d'interconnexion pour reseaux de communication amcr sans fil
WO2006051481A2 (fr) 2004-11-10 2006-05-18 Koninklijke Philips Electronics N.V. Procede de fonctionnement d'un systeme de communication, station radio et systeme de radiocommunication
WO2007073248A1 (fr) * 2005-12-20 2007-06-28 Telefonaktiebolaget Lm Ericsson (Publ) Planification des ressources dans un systeme cellulaire
WO2008108698A1 (fr) 2007-03-02 2008-09-12 Telefonaktiebolaget Lm Ericsson (Publ) Procédé et appareil pour une réutilisation de ressources dans un système de communication
EP2022180A1 (fr) * 2006-05-29 2009-02-11 Telefonaktiebolaget LM Ericsson (PUBL) Prévision de qualité de canal dans des systèmes hsdpa
EP2260668A1 (fr) * 2008-04-04 2010-12-15 Telefonaktiebolaget L M Ericsson (PUBL) Réduction de brouillage dans un réseau de communication par planification et adaptation de liaison
US8369793B2 (en) 2009-10-02 2013-02-05 Telefonaktiebolaget L M Ericsson (Publ) Channel-dependent scheduling and link adaptation
WO2023132763A1 (fr) * 2022-01-05 2023-07-13 Telefonaktiebolaget Lm Ericsson (Publ) Premier nœud de réseau, deuxième nœud de réseau, équipement utilisateur et procédés dans réseau de communication sans fil

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998000928A1 (fr) * 1996-06-28 1998-01-08 Motorola Inc. Procede et appareil de commande de puissance dans un systeme de communication
WO1999067899A1 (fr) * 1998-06-25 1999-12-29 Conexant Systems, Inc. Gestion de puissance d'un systeme telephonique par reglage dynamique de la puissance d'emission
WO2000021235A1 (fr) * 1998-10-06 2000-04-13 Telefonaktiebolaget Lm Ericsson (Publ) Modulation et codage de canal adaptatifs au niveau de la cellule
WO2000022865A2 (fr) * 1998-10-12 2000-04-20 Telefonaktiebolaget Lm Ericsson Adaptation de liaison et de cellule radio dans des systemes tdd

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998000928A1 (fr) * 1996-06-28 1998-01-08 Motorola Inc. Procede et appareil de commande de puissance dans un systeme de communication
WO1999067899A1 (fr) * 1998-06-25 1999-12-29 Conexant Systems, Inc. Gestion de puissance d'un systeme telephonique par reglage dynamique de la puissance d'emission
WO2000021235A1 (fr) * 1998-10-06 2000-04-13 Telefonaktiebolaget Lm Ericsson (Publ) Modulation et codage de canal adaptatifs au niveau de la cellule
WO2000022865A2 (fr) * 1998-10-12 2000-04-20 Telefonaktiebolaget Lm Ericsson Adaptation de liaison et de cellule radio dans des systemes tdd

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7346018B2 (en) 2003-01-16 2008-03-18 Qualcomm, Incorporated Margin control in a data communication system
WO2004066520A1 (fr) * 2003-01-16 2004-08-05 Qualcomm Incorporated Commande de la marge de puissance dans un systeme de communication de donnees
EP1830484A1 (fr) * 2003-01-16 2007-09-05 QUALCOMM Incorporated Contrôle de marge de puissance dans un système de communication de données
EP1513356A2 (fr) 2003-09-02 2005-03-09 Sony Ericsson Mobile Communications Japan, Inc. Procédé et dispositif de radiocommunication
KR101064828B1 (ko) * 2003-09-02 2011-09-14 소니 에릭슨 모빌 커뮤니케이션즈 재팬, 아이엔씨. 무선 통신 시스템 및 무선 통신 장치
EP1513356A3 (fr) * 2003-09-02 2007-06-06 Sony Ericsson Mobile Communications Japan, Inc. Procédé et dispositif de radiocommunication
US7460878B2 (en) 2003-09-02 2008-12-02 Sony Ericsson Mobile Communications Japan, Inc. Radio communication system and radio communication device that periodically compares transmission power with a maximum value to determine a transmission mode
WO2005109673A1 (fr) * 2004-05-11 2005-11-17 Koninklijke Philips Electronics N.V. Procede et dispositif de reglage de puissance avec prevision des perturbations d'interconnexion pour reseaux de communication amcr sans fil
WO2006051481A3 (fr) * 2004-11-10 2006-07-27 Koninkl Philips Electronics Nv Procede de fonctionnement d'un systeme de communication, station radio et systeme de radiocommunication
JP2008520151A (ja) * 2004-11-10 2008-06-12 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ 通信システムを動作する方法、無線局及び無線通信システム
TWI394382B (zh) * 2004-11-10 2013-04-21 Koninkl Philips Electronics Nv 用以操作一通信系統之方法、一無線電台及一無線通信系統
US8014730B2 (en) 2004-11-10 2011-09-06 Koninklijke Philips Electronics N.V. Method of operating a communication system, a radio station, and a radio communication system
CN101057415B (zh) * 2004-11-10 2012-06-20 皇家飞利浦电子股份有限公司 用于操作通信系统的方法、无线电台和无线通信系统
WO2006051481A2 (fr) 2004-11-10 2006-05-18 Koninklijke Philips Electronics N.V. Procede de fonctionnement d'un systeme de communication, station radio et systeme de radiocommunication
WO2007073248A1 (fr) * 2005-12-20 2007-06-28 Telefonaktiebolaget Lm Ericsson (Publ) Planification des ressources dans un systeme cellulaire
EP2022180A1 (fr) * 2006-05-29 2009-02-11 Telefonaktiebolaget LM Ericsson (PUBL) Prévision de qualité de canal dans des systèmes hsdpa
EP2022180A4 (fr) * 2006-05-29 2013-01-09 Ericsson Telefon Ab L M Prévision de qualité de canal dans des systèmes hsdpa
JP2010520659A (ja) * 2007-03-02 2010-06-10 テレフオンアクチーボラゲット エル エム エリクソン（パブル） 通信システムにおけるリソースの再利用のための方法及び装置
US7899015B2 (en) 2007-03-02 2011-03-01 Telefonaktiebolaget Lm Ericsson (Publ) Method and apparatus for resource reuse in a communication system
EP2119079A1 (fr) * 2007-03-02 2009-11-18 Telefonaktiebolaget LM Ericsson (PUBL) Procédé et appareil pour une réutilisation de ressources dans un système de communication
EP2119079A4 (fr) * 2007-03-02 2013-01-16 Ericsson Telefon Ab L M Procédé et appareil pour une réutilisation de ressources dans un système de communication
WO2008108698A1 (fr) 2007-03-02 2008-09-12 Telefonaktiebolaget Lm Ericsson (Publ) Procédé et appareil pour une réutilisation de ressources dans un système de communication
EP3142394A1 (fr) * 2007-03-02 2017-03-15 Telefonaktiebolaget LM Ericsson (publ) Procédé et appareil pour la réutilisation de ressources dans un système de communication
EP2260668A1 (fr) * 2008-04-04 2010-12-15 Telefonaktiebolaget L M Ericsson (PUBL) Réduction de brouillage dans un réseau de communication par planification et adaptation de liaison
EP2260668A4 (fr) * 2008-04-04 2014-07-02 Ericsson Telefon Ab L M Réduction de brouillage dans un réseau de communication par planification et adaptation de liaison
US8977311B2 (en) 2008-04-04 2015-03-10 Telefonaktiebolaget Lm Ericsson (Publ) Method and arrangement for reducing interference in a wireless communication network
EP2945451A1 (fr) * 2008-04-04 2015-11-18 Telefonaktiebolaget L M Ericsson (publ) Réduction de brouillage dans un réseau de communication par planification et adaptation de liaison
US8369793B2 (en) 2009-10-02 2013-02-05 Telefonaktiebolaget L M Ericsson (Publ) Channel-dependent scheduling and link adaptation
WO2023132763A1 (fr) * 2022-01-05 2023-07-13 Telefonaktiebolaget Lm Ericsson (Publ) Premier nœud de réseau, deuxième nœud de réseau, équipement utilisateur et procédés dans réseau de communication sans fil

Also Published As

Publication number Publication date
AU2001247037A1 (en) 2001-12-03
SE0001918L (sv) 2001-11-24
SE0001918D0 (sv) 2000-05-23

Similar Documents

Publication Publication Date Title
JP4167485B2 (ja) 無線通信システム、通信端末装置、および基地局装置
CN100362768C (zh) 时分双工通信系统中的外环/加权开环功率控制
EP2204922B1 (fr) Appareil de traitement d'informations et procédé de traitement d'informations
KR100459564B1 (ko) 이동통신시스템에서 서비스 부하를 단말기에 보고하기위한 장치 및 방법
US7386321B2 (en) Base station apparatus and radio communication method
EP0847147B1 (fr) Procédé de contrôle de la puissance d'émission pour un système de communication à AMDC
US8411615B2 (en) Power controlled adaptive modulation and coding scheme in satellite communications system
EP1322051A1 (fr) Commande de puissance et débit d'un transmission sur une fréquence porteuse
US7672685B2 (en) Transmitter and transmission control method, and receiver and reception control method
US20090291642A1 (en) Systems and Methods for SIR Estimation for Power Control
KR100322024B1 (ko) 부호분할다중접속통신시스템의전력제어장치및방법
WO2001091322A1 (fr) Procede d'adaptation de liaisons et evaluation de la qualite dans un systeme radio cellulaire
JP3662543B2 (ja) 基地局装置及びパケット伝送方法
JP4409793B2 (ja) 基地局装置および無線通信方法
EP2015476B1 (fr) Dispositif de communication mobile et procédé de création des informations concernant la qualité de réception
US8126404B2 (en) Method and device for evaluating the energy level of a radio signal
JP3357653B2 (ja) 無線受信装置
CN101390329A (zh) 发送定时控制系统和其方法以及使用其的基站和移动台站
CN101635946A (zh) 用户设备

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载