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WO2001008369A1 - Emetteur adaptatif ofdm (mrfo) - Google Patents

Emetteur adaptatif ofdm (mrfo) Download PDF

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Publication number
WO2001008369A1
WO2001008369A1 PCT/GB2000/001883 GB0001883W WO0108369A1 WO 2001008369 A1 WO2001008369 A1 WO 2001008369A1 GB 0001883 W GB0001883 W GB 0001883W WO 0108369 A1 WO0108369 A1 WO 0108369A1
Authority
WO
WIPO (PCT)
Prior art keywords
aofdm
channel
modem
video
transmission
Prior art date
Application number
PCT/GB2000/001883
Other languages
English (en)
Inventor
Lajos Hanzo
Peter John Cherriman
Thomas Keller
Original Assignee
University Of Southampton
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 University Of Southampton filed Critical University Of Southampton
Priority to AU47719/00A priority Critical patent/AU4771900A/en
Publication of WO2001008369A1 publication Critical patent/WO2001008369A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0015—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the adaptation strategy
    • H04L1/0019—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the adaptation strategy in which mode-switching is based on a statistical approach
    • H04L1/0021—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the adaptation strategy in which mode-switching is based on a statistical approach in which the algorithm uses adaptive thresholds
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
    • H04L1/0025—Transmission of mode-switching indication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
    • H04L1/0032—Without explicit signalling
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0044—Allocation of payload; Allocation of data channels, e.g. PDSCH or PUSCH
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0002—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate
    • H04L1/0003—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate by switching between different modulation schemes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0014—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the source coding

Definitions

  • the invention relates to adaptive Orthogonal Frequency Division Multiplexing (OFDM) based transmis-
  • statically reconfigurable found in this context in the literature refers to multimedia ⁇ transceivers that cannot be near-instantaneously reconfigured
  • statically reconfigurable video transceivers were reconfigured on a long-term basis under the base sta- ⁇ o tion's control, invoking for example in the central cell region - where benign channel conditions prevail it - a less robust, but high-throughput modulation mode, such as 4 bit/symbol Quadrature Amplitude Mod- i 2 ulation (16QAM), which was capable of transmitting a quadruple number of bits and hence ensured a
  • BPSK Binary Phase Shift Keying
  • the fixed bitrate ot the above propnetary video codecs is in contrast to existing standard video codecs, 0 such as the Motion Pictures Expert Group codecs known as MPEG 1 and MPEG2 or the ITU's H 263 3i codec, where the time-va ⁇ ant v ideo motion activity and the variable-length coding techniques employed 2 result in a time-va ⁇ ant bitrate fluctuation and a near-constant perceptual video quality
  • This time-va ⁇ ant 3 bitrate fluctuation can be mitigated bv employing adaptive feed-back controlled buffering, which po- 4 tentially increases the latency or delay of the codec and hence it is often objectionable for example in 5 interactive videophony
  • the schemes presented by Streit et al in References [1] result in slightly va ⁇ able 6 video quality at a constant bitrate, while refraining from employing buffering, which again, would result in latency in interactive videophony
  • Two specific embodiments are desc ⁇ bed, a fixed bitrate and a time-va ⁇ ant bitrate system
  • the time-va ⁇ ant bitrate system adjusts the number of bits mapped to the OFDM
  • the transceiver achieves always the best possible source-signal representation quality -
  • the middle graph shows the performance of the 3 4Mbps subband-adaptive
  • 1.6 represents the 7 0Mbps subband-adaptive modem, which operated at the same bitrate as
  • the Average channel SNR was 16dB 28 n ⁇ 4 Instanteous Channel SNR for all 512 subcar ⁇ ers versus time, for an average channel ng SNR of 16dB over the channel characte ⁇ sed by the impulse response ot Figure 5 29 i2o 5 Indoor three-path WATM channel impulse responce 29 FER or video packet loss ratio (PLR) versus channel SNR for the BPSK and QPSK fixed modulation mode OFDM transceivers and for the corresponding subband-adaptive ⁇ AOFDM transceiver, operating at identical effective video bitrates, namely at 3.4 and
  • the micro-adapti e nature ot the time-va ⁇ ent target bitrate subband-adaptive TVTBR- AOFDM) modem
  • the top graph is a contour plot of the channel SNR tor all 512 sub- earners versus time
  • the bottom graph shows the modulation mode chosen tor all 16 subbands tor the same penod ot time Each subband is comp ⁇ sed of 32 subcamers
  • the switched modem uses four modes, with target bitrate
  • the soft-decision channel codec met ⁇ cs can be also invoked in las estimating the instantaneous channel quality, irrespective of the type of channel impairments
  • thermore when the mobile is roaming in a hostile outdoor propagation environment, typically low-order
  • 229 AOFDM transmission parameter adaptation is an action of the transmitter in response to time-varying
  • mission parameter adaptation relies on some form ot channel estimation and signalling
  • the transmitter has to select the appropriate 238 modulation schemes tor the subcarners
  • the receiver 42 can attempt to estimate the parameters employed at the transmitter by means ot blind detection
  • the transmitter needs to communicate the transmission parameter set to 2 ⁇ the receiver ( Figure 1 (a)), or the receiver can attempt blind detection of the transmission parameters
  • the channel quality measure or the set of requested transmission parameters is
  • bits may be additionally mapped by the Mapper of Figure 2 to n number of different Forward 25 ⁇ Error Correction (FEC) protection classes These bits are then convenveyed to the optional Time Division
  • the transceiver can modulate 1 , 2 or 2 4 4 bits onto each OFDM sub-earner, or simply disable transmissions for sub-camers which exhibit a high
  • the H 263 video codec exhibits an impressive compression ratio, although this is achieved at the cost ot a
  • the subband-adaptive modem is capable of achieving a low bit
  • Table l shows the system parameters for the fixed BPSK and QPSK transceivers, as well as for the
  • each transmitted packet which is 1 1 and 12 bits/packet for BPSK and QPSK,
  • the effective video bitrates for the BPSK and QPSK modes are then 3 4 and 7 0 Mbps.
  • the fixed mode BPSK and QPSK transceivers are limited to one and two bits per symbol, respectively so? However, the AOFDM transceivers operate at the same bitrate, as their corresponding fixed modem
  • channel is of high quality - like tor example at about frame 1080 - the subband-adaptive modem used 3, the same modulation mode as the equivalent fixed rate modem in all subcarners When the channel is
  • the subband-adaptive transceivers can operate at lower channel SNRs, than the 32 ⁇ fixed modem mode transceivers, while maintaining the same required video packet loss ratio
  • 329 figure labels the subband-adaptive transeivers as ⁇ AOFDM, implying that the adaption is not noticable
  • the subband-adaptive modems employ different modulation modes tor different
  • the adaptive system can invoke less robust, but higher
  • Figure 9 shows the FER or video packet loss ratio (PLR) performance versus channel SNR for the four
  • the video packet loss ratio increases, thereby reducing the throughput bitrate, and hence the associated
  • the lower target bitrate transceivers operate at an inherently lower video quality, but they 83 are more robust to the prevailing channel conditions and hence can operate at lower channel SNRs, while
  • Figure 11(a) shows that for the target bitrate of 1 8Mbps, the system has a high
  • the subband modulation mode selection process has to be more "aggressive", resulting in 02 increased video packet loss Observe in the figure that the transceiver having an effective video bitrate of 03 3 4Mbps, exhibits increased packet loss, and in one frame as much as 5% of the packets transmitted for
  • 424 quality estimator can estimate the expected bit error ratio based on each specific modulation mode chosen
  • the channel estimator can then estimate the expected bit error ratio of
  • Figure 13(a) portrays the contour plot of the channel SNR tor each 44 subcar ⁇ er versus time
  • Figure 13(b) displays the modulation mode chosen tor each 32-subcar ⁇ er sub-
  • TVTBR time-va ⁇ ent target bitrate
  • 447 modem has an instantaneous target bitrate of 7Mbps As the channel used by the 3 4 Mbps QPSK mode 4 ⁇ degrades around frame 1060, the modem has switched to the more robust 1 8Mbps BPSK mode When
  • the channel quality is high around frames 1074- 1081 , the highest bitrate 10Mbps 16QAM mode is used 50
  • This demonstrates that the TVTBR-AOFDM modem, can reduce the number ot lost video packets, by 45i using reduced bitrate but more robust modulation modes, when the channel quality is poor
  • 52 this is at the expense ot a slightly reduced average throughput bitrate
  • througput bitrate 53 results in a higher video quality, however a high bitrate associated with a high packet loss ratio, is usually
  • a low BER switching threshold 57 implies that the switching algonthm is cautious about switching to the higher bitrate modes, and therefore
  • the system performance is charactensed by a low video packet loss ratio, and a low throughput bitrate
  • FIG. 462 Figure 14 portrays the video packet loss ratio or FER performance of the TVTBR-AOFDM modem for
  • TVTBR-AOFDM 465 adaptive (TVTBR-AOFDM) modem has a similar packet loss ratio performance to that of the 1 8Mbps
  • CTBR constant target bitrate
  • Figure 16 portrays the corresponding effective throughput bitrate versus channel SNR for a range ot
  • PSNR peak-signai-to-noise ratio
  • the PSNR curve typically reverts to the error-free PSNR performance curve in the next frame
  • the BER switching threshold was further increased to 3%, which is not shown in the figure, the maximum
  • Figure 17(c) portrays the PSNR and packet loss performance tor a BER switching threshold of 5%
  • the 5o ⁇ PSNR degradation in this case ranges from 1 8 to 13dB and all video frames contain at least one lost
  • S Figure 1 8(a) compares the average PSNR versus channel SNR performance for a range of switched sis (TVTBR) and un-switched (CTBR) AOFDM modems. The figure compares the four un-switched, le.
  • TVTBR switched sis
  • CBR un-switched
  • threshold of about BER 1 %.
  • the subband adaptive modem could invoke BPSK. QPSK. 540 or 16Q AM modulation for each subband or disable transmission for a subband, if the channel conditions
  • Section 4 5 we compared the performance of subband adaptive OFDM modems, operating at different
  • CTBR-AOFDM constant target bitrate subband adaptive OFDM
  • TVTBR-AOFDM modems can provide a balanced video quality performance, across a wider range of
  • a reliable near-instantaneous channel quahtv metric is employed in order to appropnatelv configure the AOFDM modem for maintaining the required target BER and the associated source signal representation quality
  • the perceived channel quality determines the number of bits that can be transmitted in a given OFDM transmission burst which in tum predetermines the number ot bits to be generated by the associated multimedia source codec, such as for example the associated video, audio or speech codec
  • the multimedia source codec has to be capable of adjusting the number of bits generated under the instruction ot the burst-bv-burst adaptive OFDM transceiver
  • the OFDM transmitter mode requested by the receiver in order to achieve the target performance has to be signalled by the receiver to the remote transmitter
  • the uplink and downlink channel quality is sufficiently similar for allowing the receiver to judge what transmission mode the associated transmitter should use, in order for its transmitted signal to man- tain the required transmission integ ⁇ ty
  • the mode of operation used by the transmitter can also be detected using blind detection techniques, for example in conjunction with the associated channel decoder
  • the subband adaptive modems may provide a lower BER, than the corresponding conventional BPSK or QPSK OFDM modems at the same channel SNR This was achieved by transmitting more bits in the higher-quality subbands, and less bits in the lower-quality subbands, thereby reducing the chances of corrupted bits
  • the lower BER of the subband adaptive OFDM modems provided a higher effective video bitrate for the video codec in the studied embodiment of the proposed system which in turn provided a higher video quahtv
  • the subband adaptive modem could operate at lower channel SNRs while maintaining the required video quahtv
  • 604 channel quahtv was high and a lower bitrate when the overall channel quality was poor, in order o05 to maintain the required video quality
  • CTBR-AOFDM constant target bitrate subband adaptive OFDM
  • 6o ⁇ switched TVTBR-AOFDM modems can provide a balanced video quality performance, across a
  • VTC'99 (Spring), (Houston, Texas, USA), IEEE, 16-20 May 1999.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Quality & Reliability (AREA)
  • Artificial Intelligence (AREA)
  • Physics & Mathematics (AREA)
  • Probability & Statistics with Applications (AREA)
  • Detection And Prevention Of Errors In Transmission (AREA)

Abstract

Le système concerne une gamme de systèmes vidéo à multiplex adaptatif par répartition en fréquence orthogonale (AOFDM) destinés aux communications interactives par canaux sans fil. Les modems adaptatifs OFDM à sous-bande avec débit binaire cible constant (CTBR-AOFDM) permettent d'assurer un TEB plus faible qu'un modem traditionnel correspondant à OFDM. Des modems à peine plus complexes du type commutés adaptatifs OFDM avec débit binaire cible variable dans le temps (TVTBR-AOFDM) permettent d'assurer une performance de qualité vidéo équilibrée sur une gamme plus large de SNR de canaux. L'avantage principal de la technique proposée consiste en ce que l'émetteur-récepteur, indépendamment des conditions de canal prépondérantes, assure toujours la meilleure qualité possible de la représentation source-signal (par exemple, de la qualité audio ou vidéo), et ce grâce à l'ajustement automatique du débit binaire réalisable et de la qualité de représentation source-signal multimédia associée, qui vise à s'adapter à la qualité de canal existante. Cela ce fait presque instantanément dans des conditions de propagation données afin de compenser les effets de perte de voie, d'évanouissement rapide, d'évanouissement lent, de dispersion, etc. En outre, lorsque le portable est en itinérance dans un environnement extérieur de propagation hostile, on fait généralement appel à de faibles débits de modem, d'un ordre peu élevé, alors que dans des environnements intérieurs favorables on utilise majoritairement des modes de qualité élevée de représentation source-signal, avec des débits élevés.
PCT/GB2000/001883 1999-07-26 2000-05-16 Emetteur adaptatif ofdm (mrfo) WO2001008369A1 (fr)

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AU47719/00A AU4771900A (en) 1999-07-26 2000-05-16 Adaptive ofdm transmitter

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GBGB9917512.7A GB9917512D0 (en) 1999-07-26 1999-07-26 Data and/or video communications

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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003001761A1 (fr) * 2001-06-22 2003-01-03 Qualcomm Incorporated Procede et appareil de transmission de donnees dans un systeme duplex a repartition dans le temps
WO2003055099A1 (fr) * 2001-12-21 2003-07-03 Nokia Corporation Estimation de parametres pour systeme d'antenne adaptative
EP1355467A1 (fr) * 2002-04-16 2003-10-22 Sony International (Europe) GmbH Système pour le multiplexage par division en fréquences orthogonales (OFDM) avec prédiction du canal
WO2004017554A1 (fr) * 2002-08-14 2004-02-26 Koninklijke Philips Electronics N.V. Selection entre deux schemas de codage differents et schemas de modulation correspondants dependant du temps de transmission des donnees admissible
EP1515469A2 (fr) * 2003-09-10 2005-03-16 Hitachi Communication Technologies, Ltd. Procédé et système de radiocommunication avec modulation/démodulation adaptative
US7327795B2 (en) 2003-03-31 2008-02-05 Vecima Networks Inc. System and method for wireless communication systems
US7327800B2 (en) 2002-05-24 2008-02-05 Vecima Networks Inc. System and method for data detection in wireless communication systems
EP2173049A1 (fr) * 2007-06-25 2010-04-07 Panasonic Corporation Dispositif de communication, circuit intégré, et méthode et programme de régulation de la vitesse de transmission
CN101841392A (zh) * 2003-12-29 2010-09-22 英特尔公司 用于交换信道信息的方法和设备
EP1947884A3 (fr) * 2007-01-22 2011-06-15 Broadcom Corporation Procédé et système pour la sélection de fréquence de contrôle d'accès de support (MAC)
WO2011126808A2 (fr) 2010-03-29 2011-10-13 The Trustees Of The University Of Pennsylvania Système d'ablation de transgène induit pharmacologiquement
US8068547B2 (en) 2008-05-09 2011-11-29 Lantiq Deutschland Gmbh Data communication
CN101133565B (zh) * 2005-01-27 2014-12-24 高通股份有限公司 用于时分双工通信系统的信道校准的方法和装置
US9935705B2 (en) 1999-08-03 2018-04-03 Wi-Lan Inc. Frame structure for an adaptive modulation wireless communication system
US10117234B2 (en) 2000-11-15 2018-10-30 Wi-Lan, Inc. Framing for an adaptive modulation communication system

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5479447A (en) * 1993-05-03 1995-12-26 The Board Of Trustees Of The Leland Stanford, Junior University Method and apparatus for adaptive, variable bandwidth, high-speed data transmission of a multicarrier signal over digital subscriber lines
EP0869647A2 (fr) * 1997-04-01 1998-10-07 Lucent Technologies Inc. Système de modulation multiporteuse à paramètres de fonctionnement dynamiquement réglables
WO1999016224A1 (fr) * 1997-09-23 1999-04-01 Telefonaktiebolaget Lm Ericsson (Publ) Attribution moins complexe de bits aux sous-canaux d'un systeme de transmission tres rapide de donnees a plusieurs porteuses

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5479447A (en) * 1993-05-03 1995-12-26 The Board Of Trustees Of The Leland Stanford, Junior University Method and apparatus for adaptive, variable bandwidth, high-speed data transmission of a multicarrier signal over digital subscriber lines
EP0869647A2 (fr) * 1997-04-01 1998-10-07 Lucent Technologies Inc. Système de modulation multiporteuse à paramètres de fonctionnement dynamiquement réglables
WO1999016224A1 (fr) * 1997-09-23 1999-04-01 Telefonaktiebolaget Lm Ericsson (Publ) Attribution moins complexe de bits aux sous-canaux d'un systeme de transmission tres rapide de donnees a plusieurs porteuses

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
KELLER T ET AL: "Blind-detection assisted sub-band adaptive turbo-coded OFDM schemes", IEEE 49TH VEHICULAR TECHNOLOGY CONFERENCE, vol. 1, 16 May 1999 (1999-05-16) - 20 May 1999 (1999-05-20), Piscataway, NJ, USA, IEEE, USA, pages 489 - 493, XP002144718, ISBN: 0-7803-5565-2 *
KELLER T ET AL: "Sub-band adaptive pre-equalised OFDM transmission", IEEE VTS 50TH VEHICULAR TECHNOLOGY CONFERENCE, vol. 1, 19 September 1999 (1999-09-19) - 22 September 1999 (1999-09-22), Piscataway, NJ, USA, pages 334 - 338, XP002144719, ISBN: 0-7803-5435-4 *
L. HANZO, C.H. WONG, P. CHERRIMAN: "Burst-by-burst Adaptive Wideband Wireless Video Telephony", INTERNET ARTICLE, 13 April 2000 (2000-04-13), XP002144720, Retrieved from the Internet <URL:http://www-mobile.ecs.soton.ac.uk/hanzo/papers/invited-signal-proc-web.html> [retrieved on 20000810] *

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9935705B2 (en) 1999-08-03 2018-04-03 Wi-Lan Inc. Frame structure for an adaptive modulation wireless communication system
US10873930B2 (en) 2000-11-15 2020-12-22 Wi-Lan Inc. Framing for an adaptive modulation communication system
US10117234B2 (en) 2000-11-15 2018-10-30 Wi-Lan, Inc. Framing for an adaptive modulation communication system
US7333560B2 (en) 2001-06-22 2008-02-19 Qualcomm Incorporated Method and apparatus for transmitting data in a time division duplexed (TDD) communication system
US7729444B2 (en) 2001-06-22 2010-06-01 Qualcomm Incorporated Method and apparatus for transmitting data in a time division duplexed (TDD) communication system
US7027523B2 (en) 2001-06-22 2006-04-11 Qualcomm Incorporated Method and apparatus for transmitting data in a time division duplexed (TDD) communication system
CN1309231C (zh) * 2001-06-22 2007-04-04 高通股份有限公司 在时分双工系统内发送数据的方法和装置
WO2003001761A1 (fr) * 2001-06-22 2003-01-03 Qualcomm Incorporated Procede et appareil de transmission de donnees dans un systeme duplex a repartition dans le temps
US8121217B2 (en) 2001-06-22 2012-02-21 Qualcomm Incorporated Method and apparatus for transmitting data in a time division duplexed (TDD) communication system
WO2003055099A1 (fr) * 2001-12-21 2003-07-03 Nokia Corporation Estimation de parametres pour systeme d'antenne adaptative
EP1355467A1 (fr) * 2002-04-16 2003-10-22 Sony International (Europe) GmbH Système pour le multiplexage par division en fréquences orthogonales (OFDM) avec prédiction du canal
US7386072B2 (en) 2002-04-16 2008-06-10 Sony Deutschland Gmbh Orthogonal frequency division multiplexing (OFDM) system with channel transfer function prediction
US7327800B2 (en) 2002-05-24 2008-02-05 Vecima Networks Inc. System and method for data detection in wireless communication systems
WO2004017554A1 (fr) * 2002-08-14 2004-02-26 Koninklijke Philips Electronics N.V. Selection entre deux schemas de codage differents et schemas de modulation correspondants dependant du temps de transmission des donnees admissible
CN100420175C (zh) * 2002-08-14 2008-09-17 皇家飞利浦电子股份有限公司 依照可允许的数据传输延迟来选择不同的编码方案和相应的调制方案
US7327795B2 (en) 2003-03-31 2008-02-05 Vecima Networks Inc. System and method for wireless communication systems
EP1860812A2 (fr) 2003-09-10 2007-11-28 Hitachi Communication Technologies, Ltd. Dispositif de réception dans un système de communication radio
KR101022951B1 (ko) 2003-09-10 2011-03-16 가부시키가이샤 히타치세이사쿠쇼 적응 변복조방식 및 무선통신 시스템
EP1515469A2 (fr) * 2003-09-10 2005-03-16 Hitachi Communication Technologies, Ltd. Procédé et système de radiocommunication avec modulation/démodulation adaptative
EP1515469A3 (fr) * 2003-09-10 2005-05-18 Hitachi Communication Technologies, Ltd. Procédé et système de radiocommunication avec modulation/démodulation adaptative
US7363007B2 (en) 2003-09-10 2008-04-22 Hitachi Communication Technologies, Ltd. Adaptive modulation/demodulation method and radio communications systems
EP1860812A3 (fr) * 2003-09-10 2008-12-17 Hitachi Communication Technologies, Ltd. Dispositif de réception dans un système de communication radio
CN101841392B (zh) * 2003-12-29 2013-11-20 英特尔公司 用于交换信道信息的方法和设备
CN101841392A (zh) * 2003-12-29 2010-09-22 英特尔公司 用于交换信道信息的方法和设备
EP2259468A3 (fr) * 2003-12-29 2011-11-23 Intel Corporation Procédé et appareil pour l'échange d'informations de canal
US8289865B2 (en) 2003-12-29 2012-10-16 Intel Corporation Method and apparatus to exchange channel information
CN101133565B (zh) * 2005-01-27 2014-12-24 高通股份有限公司 用于时分双工通信系统的信道校准的方法和装置
US8144608B2 (en) 2007-01-22 2012-03-27 Broadcom Corporation Method and system for medium access control (MAC) rate selection
EP1947884A3 (fr) * 2007-01-22 2011-06-15 Broadcom Corporation Procédé et système pour la sélection de fréquence de contrôle d'accès de support (MAC)
EP2173049A4 (fr) * 2007-06-25 2014-01-15 Panasonic Corp Dispositif de communication, circuit intégré, et méthode et programme de régulation de la vitesse de transmission
EP2173049A1 (fr) * 2007-06-25 2010-04-07 Panasonic Corporation Dispositif de communication, circuit intégré, et méthode et programme de régulation de la vitesse de transmission
US8068547B2 (en) 2008-05-09 2011-11-29 Lantiq Deutschland Gmbh Data communication
WO2011126808A2 (fr) 2010-03-29 2011-10-13 The Trustees Of The University Of Pennsylvania Système d'ablation de transgène induit pharmacologiquement

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