结合数字锁相环空间分集判决反馈盲均衡算法

为了克服常数模算法(Constant Modulus Algorithm,CMA)收敛速度慢、稳态误差大及复信道引起相位旋转的缺点,提出了结合数字锁相环的等增益合并空间分集判决反馈盲均衡算法。该算法利用空间分集技术来提高信噪比,利用判决反馈盲均衡器来克服码间干扰,利用二阶锁相环来跟踪信道的时变特性,具有纠正相位旋转、收敛速度较快、稳态误差小的优点。时变多普勒频移水声信道的仿真结果,验证了该算法的有效性。

Spatial Diversity Decision Feedback Blind Equalization Algorithm with Digital Phase-Locked Loop Structure

In order to overcome the disadvantages of low convergent rate of Constant Modulus Algorithm(CMA),big steady-state error and carrier phase rotation caused by complex communication channel,spatial diversity decision feedback blind equalization algorithm with digital phase-locked loop structure was proposed.The proposed algorithm can improve signal-to-noise by spatial diversity technique,overcame intersymbol interference by decision feed-back blind equalizer,and trace time-varying characteristic by two-order phase-locked loop,which has ability to compensate carrier phase rotation,to improve the convergence rate,and to reduce steady-state error.The validity of the proposed algorithm was proved by computer simulation of underwater acoustics channel with time-varying Dopple frequency-shift.