BER Performance Improvement of Alamouti MIMO-STBC Decoder Using Mutual Information Method

Abstract

Bit error rate (BER) performance of multiple input multiple output (MIMO) space time block code (STBC) decoder depends on the channel estimator quality, where the quality of classical least square (LS) estimator depends mainly on the number of pilot symbols. The aims of this paper are to implement a new STBC decoder, measure the BER performance and make comparison with conventional one, without increasing the number of pilot symbols. Although the new strategy is more complex than a conventional decoder, it gives the opportunity to join estimation and decoding at the same time. Minimum mutual information (MMI)- independent component analysis (ICA) algorithm has been used for extracting source signals. MIMO-STBC systems were taken as a cases study with two transmitters. The simulation results show that MMI-ICA algorithm provides superior BER performance as compared with conventional maximum ratio combiner (MRC). The important point, which denoted during simulation, the performance of ICA algorithm with high frame length provides better BER performance than the conventional one.