WLC26-1: Soft Decision Equalization of Multiple Antenna Systems over Dispersive Channels via Max-log-MAP Sphere Decoder

In this paper, we propose a multistage soft decision equalization (SDE) technique using max-log-MAP sphere decoder (MLMSD) for block transmission over frequency selective multi-input multi-output (MIMO) channels. Using the Toeplitz structure of the channel matrix, we convert the general signal model into a series of small-sized sub-signal models. We propose to use MLMSDs based on these sub-models to iteratively cancel interferences and get the estimations of the transmitted symbols. Simulation shows that when the block size is large, the proposed algorithm outperforms the Schnorr-Euchner sphere decoder and the probability data association SDE with a reasonable computational complexity in full-rank MIMO channels.

[1]  Mong-Suan Yee Max-log-MAP sphere decoder , 2005, Proceedings. (ICASSP '05). IEEE International Conference on Acoustics, Speech, and Signal Processing, 2005..

[2]  Babak Hassibi,et al.  Maximum-Likelihood Sequence Detection of Multiple Antenna Systems over Dispersive Channels via Sphere Decoding , 2002, EURASIP J. Adv. Signal Process..

[3]  Inkyu Lee,et al.  A new reduced-complexity sphere decoder for multiple antenna systems , 2002, 2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333).

[4]  C. Tellambura,et al.  An efficient generalized sphere decoder for rank-deficient MIMO systems , 2004 .

[5]  Giuseppe Caire,et al.  On maximum-likelihood detection and the search for the closest lattice point , 2003, IEEE Trans. Inf. Theory.

[6]  Zhi Tian,et al.  Near-optimum soft decision equalization for frequency selective MIMO channels , 2004, IEEE Trans. Signal Process..

[7]  James K. Cavers,et al.  Symbol by symbol soft-input soft-output multiuser detection for frequency selective MIMO channels , 2005, IEEE Wireless Communications and Networking Conference, 2005.

[8]  Björn E. Ottersten,et al.  On the complexity of sphere decoding in digital communications , 2005, IEEE Transactions on Signal Processing.