用于ADSL中的变步长LMS算法

本文给出了一种改进的LMS算法，该算法可应用于非对称数字用户线中实现回波抵消功能，从而在低频段的子通道内同时传输上行和下行的数据。新算法利用误差信号的相关值调节算法步长，具有较好的抗干扰性能，解决了算法收敛时间和稳态误差间的矛盾，为实际应用提供了更大的控制灵活性。仿真结果表明，在低信噪比的环境中，改进算法的收敛速度和稳态误差等性能指标都有较大的提高。并对随机出现的脉冲干扰表现出较好的鲁棒性。

A modified LMS algorithm for ADSL

A modified LMS algorithm was introduced in this paper. The proposed algorithm is suitable for echo cancellation in ADSL, achieving both upstream and downstream data transmissions in the same sub-channels. Utilizing the correlation characteristic of output error signal with previous iteration error signal, the algorithm can effectively adjust the step-size while maintaining the immunity against noise disturbance. The proposed algorithm allows more flexible control of misadjustment and convergence time without the compromise one for the other. The simulation results demonstrate that the given algorithm has significant improvement in convergence rate and misadjustment than other algorithms in low SNR environment. Simulations also show that the algorithm is robust to an abrupt impulse interference. And the modified algorithm increases less computation complexity in implementation.