基于迭代原理的低复杂度均衡算法

研究了均衡和信道译码的联合迭代译码，在此基础上提出了一种基于迭代原理的低复杂度均衡算法。算法通过将指数运算近似为乘累加运算，然后在不同时机分别利用最小均方误差符号估计值或信道译码器反馈的先验信息来计算迭代均衡中的软信息，避免了在信号空间中的穷尽搜索计算，从而降低了复杂度。仿真和分析表明，在多径信道下，该算法以些微性能损失为代价有效的降低了均衡计算复杂度，尤其适用于高阶调制方式。当采用8PSK调制方式时，本文算法对于均衡过程中复杂度较高的ρ_n,i的计算次数仅为原来的1/4。 

A Low Complexity Equalization Algorithm Based on Iteration

Abstract: In this paper, the iteration of joint equalization and decoding is studied. And it presents a low complexity equalization algorithm based on iteration. The algorithm approximates the exponential operation to the Accumulation operation, and then computes the soft information of the iteration equalization through the minimum mean square error estimated symbol or the priori information feedback from the decoding respectively in the different situations. So it avoids the exhaustive search among the constellation, and reduces the complexity accordingly. The simulation and the analyses show that it reduces the complexity effectively at the cost of negligible deterioration on the performance suffering the ISI channel. And it is effectively especially for the high order modulation. The computing times of ρ_n,i which is more complicated in equalization in my algorithm is only one fourth of the original algorithm.