Soft-output equalization and TCM for wireless personal communication systems

Yue Chen, Khaled Ben Letaief, Justin C.I. Chuang

Research output: Contribution to journalArticle

24 Citations (Scopus)


This paper investigates the use of a maximum a posteriori probability (MAP) algorithm to realize soft-output equalization in a concatenated equalization and trellis-coded modulation (TCM) decoding-based wireless communication system. Specifically, we first begin with a general MAP algorithm and then focus on studying Bahl's MAP and Lee's MAP algorithms. We then propose a modified version of Lee's MAP algorithm which is much simpler than the original, in terms of complexity, and is more practical. In particular, a very simple channel estimation method which employs orthogonal training sequences is proposed. In order to improve the system performance, equal-gain combining and selection diversity will be also considered. Finally, we compare the performance of the MAP algorithm-based equalization with our previously proposed equalization scheme, which combines decision feedback equalization and TCM.

Original languageEnglish
Pages (from-to)1679-1689
Number of pages11
JournalIEEE Journal on Selected Areas in Communications
Issue number9
Publication statusPublished - 1 Dec 1998



  • Equalization
  • Frequency-selective fading
  • MAP algorithm
  • Trellis-coded modulation (TCM)
  • Wireless personal communications

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Electrical and Electronic Engineering

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