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Adaptive thu phát không dây P14

In [515] the encoding and decoding processes as well as the various design trade-offs of space-time block codes [7,2 18,5 were reviewed. More explicitly, various previously pro161 posed space-time block codes [218,5 161 have been discussed and their performance was investigated over perfectly interleaved, non-dispersive Rayleigh fading channels. A range of systems consisting of space-time block codes and different channel codecs were investigated. The performance versus estimated complexity trade-off of the different systems was investigated and compared | Adaptive Wireless Tranceivers L. Hanzo C.H. Wong M.S. Yee Copyright 2002 John Wiley Sons Ltd ISBNs 0-470-84689-5 Hardback 0-470-84776-X Electronic Chapter 14 Space-Time Trellis Coding versus Adaptive Modulation T.H. Liew and L. Hanzo1 14.1 Introduction In 515 the encoding and decoding processes as well as the various design trade-offs of space-time block codes 7 218 516 were reviewed. More explicitly various previously proposed space-time block codes 218 516 have been discussed and their performance was investigated over perfectly interleaved non-dispersive Rayleigh fading channels. A range of systems consisting of space-time block codes and different channel codecs were investigated. The performance versus estimated complexity trade-off of the different systems was investigated and compared. In an effort to provide as comprehensive a technology road-map as possible and to identify the most promising schemes in the light of their performance versus estimated complexity in this chapter we shall explore the family of space-time trellis codes 217 517-521 which were proposed by Tarokh et al. Space-time trellis codes incorporate jointly designed channel coding modulation transmit diversity and optional receiver diversity. The performance criteria for designing space-time trellis codes were outlined in 217 under the assumption that the channel is fading slowly and that the fading is frequency non-selective. It was shown in 217 that the system s performance is determined by matrices constructed from pairs of distinct code sequences. Both the diversity gain and coding gain of the codes are determined by the minimum rank and the minimum determinant 217 522 of the matrices respectively. The results were then also extended to fast fading channels. The space-time trellis codes proposed in 217 provide the best tradeoff between data rate diversity advantage and trellis 1 Space-Time Trellis Coding and Space-Time Block Coding versus Adaptive Modulation An Overview and Comparative