The effect of decision delay on MMSE-TH precoding systems

Minimum mean square error Tomlinson-Harashima (MMSE-TH) precoding is an important nonlinear precoding method. In this paper, the effect of decision delay on the performance of MMSE-TH precoding systems is investigated over time invariant and Rayleigh fading channels, respectively. Based on the observation on the expression of the interference signal power, we propose a method of searching for the optimum decision delay to minimize the interference signal power. Moreover, the complexity of the proposed method has also been analyzed. Computer simulation shows that the system bit error ratio (BER) varies with different decision delay, and less interference signal power renders smaller BER. The results imply that we can find the optimal decision delay by the proposed method and configure it in MMSE-TH system in advance, so that the BER can achieve the minimum.