针对线性群时延畸变的加权多模盲均衡算法

群时延失真是影响卫星通信系统误码性能的重要因素之一。本文分析了高速卫星信道的线性群时延模型，依此模型提出了改进的加权多模盲均衡算法(MWMMA)。该算法引入Sigmoid函数的变形形式，构造了加权幂指数随迭代误差自适应变化的函数关系，在不需要通过大量仿真实验预先确定模式转变门限值的前提下，利用迭代误差的递减实现算法从MCMA模式通过多模自适应切换为DD模式。通过对多种算法的仿真比较，得到该算法不仅能使通过群时延信道的16QAM信号收敛集中，而且具有更小的稳态剩余码间干扰；同时，基于该算法对64QAM和256QAM传输信号的均衡仿真结果，验证了该算法对高阶QAM信号的均衡具有一定的适用性。 

Weighted Multimodulus Blind Equalization Algorithm for The Linear Group Delay Distortion

Group delay distortion is one of the important factors influencing satellite communication system BER performance.This paper analyzed the linear group delay model for the high speed data transmission satellite channel,and proposed an modified weighted multimodulus blind equalization algorithm(MWMMA).The algorithm constructs a function between the weighted exponent and the iterative error based on the deformation form of Sigmoid function,which does not need the predetermined threshold value from extensive simulation experiments,making the algorithm from MCMA mode through a multimode adaptive switching to DD mode by the iterative error decreasing.Through matlab simulations of various algorithms,the new algorithm can not only make 16QAM signal passed the group delay channel convergence focus,but has least steady residual inter symbol interference;at the same time,based on the simulation result of equalizing 64QAM and 256QAM transmission signal with the new algorithm,verifies that the algorithm has certain applicability for high order QAM signal equalization.