半盲OFDM频域联合均衡算法

摘要

Traditional frequency domain constant modulus algorithm used to be combined with hard decision-directed method. But the hard decision would induce decision fault which led to slower convergence and bigger stable MSE. In order to solve this problerm,this paper cooperated with soft decision-directed (SDD) and proposed a joint semi-blind equalization scheme of OFDM frequency domain based on CMA. According to simulation results, this algorithm has better error bit ration performance than single CMA scheme, even to reach 10-5 in environment of 25 dB SNR. It could track and equalize fast time-varying channel.%传统的频域恒模盲均衡算法通常与星座图硬判决相结合,而硬判决方法会引起判决符号错误,导致收敛慢、稳态误差大.为解决这一问题,将软判决引导与恒模算法相结合,提出了一种半盲联合频域均衡算法.仿真表明,与采用单一恒模算法相比,该算法的误码率性能明显提高,在信噪比为25 dB时就可达到10-5,有效地实现了对时变信道的跟踪和均衡.