MIMO-OFDM Precoding Technique for Minimizing BER Upper Bound of MLD


IEICE TRANSACTIONS on Communications   Vol.E91-B    No.7    pp.2287-2298
Publication Date: 2008/07/01
Online ISSN: 1745-1345
DOI: 10.1093/ietcom/e91-b.7.2287
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
mobile communication,  MIMO-OFDM,  ML detection,  precoding,  minimum BER,  pairwise error,  

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This paper proposes a new MIMO-OFDM precoding technique that aims to minimize a bit error rate (BER) upper bound of the maximum likelihood detection (MLD) in mobile radio communications. Using a steepest descent algorithm, the proposed method estimates linear precoding matrices that can minimize the upper bound of BER under power constraints. Since the upper bound is derived from all the pairwise error probabilities, this method can effectively optimize overall Euclidean distances between signals received by multiple antennas and their replicas. Computer simulations evaluate the BER performance and channel capacity of the proposed scheme for 22 and 44 MIMO-OFDM systems with BPSK, QPSK, and 16 QAM. It is demonstrated that the proposed precoding technique is superior in terms of average BER to conventional precoding methods including a precoder which maximizes only the minimum Euclidean distance as the worst case.