Space-Time Decision-Directed Equalizer for SIMO Systems based on Affine Projection Algorithm

Abstract

This paper introduces a space-time decision feedback equalizer whose coefficients are recursively renewed on the basis of the modified affine projection algorithm (APA). Despite its effectiveness against the rank deficiency problem, the complexity of the conventional APA utilizing the sample matrix inversion (SMI) is considerable. Furthermore, the shift invariance property could not be exploited in the case of the space-time decision directed equalizer (STDE) application. To overcome such challenges, this paper introduces an APA employing hyperplane projection scheme reducing the computational complexity without any degradation of convergence characteristic and tracking capability. The performance of the proposed equalization methodology is verified by showing its superior bit error rate (BER) behaviors via performing adaptive STDE under single-input-multiple-output (SIMO) wireless multipath fading channel.