新的混合型盲均衡算法

针对恒模算法(CMA)仅适用于模值为常数的信号,对高阶QAM信号的均衡效果差这一问题,结合CMA与判决引导(DD)算法各自的优点,提出一种CMA与DD算法相结合的改进混合型算法。在算法初期,利用CMA+DD并行算法使系统眼图睁开;然后,再转换到DD算法来进一步减小剩余误差。仿真结果表明,采用新算法对高阶信号均衡有较快的收敛速度和较小的剩余误差,星座图恢复很紧凑,并且改进算法能修正相位和跟踪信道。

New mixed blind equalization algorithm

Constant Modulus Algorithm(CMA) is only suited to balance the signals with modulus of the same value,but not suited to balance the high-order Quadrature Amplitude Modulation(QAM) signals.Combined with the virtues of CMA and Decision-Directed(DD) algorithm,an improved mixed blind equalization algorithm had been presented.First,the improved algorithm would make the system eye open using the CMA+DD parallel algorithm,and then switch to the DD algorithm to further reduce the residual error.The simulation results indicate that the improved algorithm has a very fast convergence speed,as well as a very small residual error for high-order QAM signals,and constellation recovery plan is very tight.Meanwhile,the improved algorithm can correct phase,and trace channel.