Iterative joint optimization of minimal transmit redundancy FIR zero-forcing precoder-equalizer system for MIMO-ISI channel

An iterative joint FIR precoder-equalizer optimization algorithm for MIMO ISI channel is proposed. This algorithm provides a suboptimal solution of the FIR zero-forcing precoder (ZFP) and equalizer (ZFE) for the space-time modulated code (STMC) system. Although serval joint precoder-equalizer design methods for MIMO ISI were proposed, existing design methods require a long guard period, which is larger than or equal to the channel order, to be inserted in the transmitted signal for avoiding the inter-block interference (IBI). This reduces the spectral efficiency of those systems. In this paper, we adopted the STMC structure, which does not require a long guard period. Using the FIR LS ZFE designing techniques previously proposed by us, we proposed a FIR LS ZFP design method. By combining the proposed ZFP design method with the ZFE design method, we propose an iterative joint FIR precoder-equalizer optimization algorithm. Although the iterative algorithm can only provide the suboptimal precoder-equalizer design, simulation results showed that substantial performance gain can be obtained when comparing with those cases without the joint precoder-equalizer design.