Joint multiuser equalization and Group decoding for asynchronous trellis-coded multiple-access channels

GRACIELA CORRAL BRIONES; MARIO R. HUEDA; CARMEN E. RODRIGUEZ

IEEE TRANSACTIONS ON COMMUNICATIONS

IEEE

Año: 2006 p. 445 - 445

0090-6778

educed-complexity multiuser interference equalization and group decoding (ME-GD) is an attractive way to improve performance of multiuser transmissions for narrowband additive white Gaussian noise channels. ME-GD receivers have been investigated in the past for convolutionally coded synchronous multiple-access channels (MACs). In this paper, we propose a new ME-GD for trellis-coded asynchronous MACs. The coding information of a subset of users and the multiuser interference are jointly taken into account in the branch metric computation using per-survivor processing. The novel approach leads to a family of Viterbi decoders which offers a good tradeoff between performance and complexity. As a second contribution of this paper, we derive theoretical bounds for the performance of ME-GD considering the effect of error propagation, which is critical for asynchronous MACs. Numerical results show the excellent accuracy of the proposed bounds. Finally, based on the novel theoret