A New Space-Time Multiple Trellis Coded Modulation Scheme for Flat Fading Channels

Susu JIANG  Ryuji KOHNO  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E87-A   No.3   pp.640-648
Publication Date: 2004/03/01
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Applications and Implementations of Digital Signal Processing)
Category: Communication Theory and Systems
space-time multiple trellis coded modulation,  diversity,  convolutional code,  Viterbi decoding,  intra-distance,  

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Recently, space-time multiple trellis coded modulation (ST-MTCM) has been introduced in order to achieve maximum transmit diversity gain and larger coding gain with the existance of parallel paths, which can not be achieved with STTCM system. In order to achieve good performance, it is crucial to maximize the intra-distance, which is defined by parallel paths and determine the performance. Conventional ST-MTCM uses a generator matrix G for coded modulation; however, we find that no matrix can be designed which can maximize the intra-distance by computer search. In this paper, we focus on maximizing the intra-distance and the diversity gain, and hence design a new coded modulation scheme. We use trellis codes in this paper which cannot be described by a matrix G. The proposed codes can achieve the maximum intra-distance and thus good coding gain, which may not be achieved by conventional codes. We also show that the proposed code can achieve good performance both in quasi-static and fast flat fading channels without the need for changing the codes as is necessary in the conventional ST-MTCM scheme.