基于T/4分数间隔的盲均衡算法研究

为了克服波特间隔常数模算法和T/2（T为字符间隔）分数间隔常数模算法收敛速度慢、稳态误差大的缺点,提出了基于T/4分数间隔的常数模盲均衡新算法,推导了4倍过采样多速率系统和1输入4输出多信道系统模型的公式。该算法采用T/4分数间隔均衡器采样,其采样频率大于奈奎斯特频率,从而避免了因欠采样引起的频谱混叠,均衡器可以更有效地对失真信道进行补偿。与波特间隔、T/2分数间隔均衡器相比,该算法收敛速度快、稳态误差小。多径水声信道盲均衡的仿真实验,验证了该算法的性能。

Study on Blind Equalization Algorithm Based on T/4 Fractionally Spaced Equalizer

A new blind equalization algorithm of T/4 Fractionally Spaced Equalizer based on Constant Modulus Algorithm(T/4-FSE-CMA) is proposed to improve the convergence rate and reduce mean square error of the Baud Spaced Equalizer based on Constant Modulus Algorithm(BSE-CMA) and T/2 Fractionally Spaced Equalizer based on Constant Modulus Algorithm(T/2-FSE-CMA) .The formulas of multi-speed system model of four times oversampled received signals and multi-channel system model of single-input-four-output are derived. The sample frequency of T/4-FSE-CMA is bigger than the frequency of Nyquist,so the frequency chaos are avoided and the input signals to equalizer contain more channel information that is of great benefit to tracking the time-varying channel. Comparing with BSE-CMA and T/2-FSE-CMA,the proposed algorithm has the characteristic of faster convergence and smaller mean square error. The efficiency of the proposed algorithm is proved by computer simulation in multi-path water channels.