用户下线时抑制串音的自更新算法

摘要

串音是影响VDSL2系统传输性能的主要因素.已有的串音抑制算法大都局限于串音用户不变的环境.在实际系统中,用户随时可能下线和上线,导致串音环境发生改变.本文重点研究了有用户下线时的情形,利用矩阵初等变换和矩阵分块,提出了一种抑制串音干扰的自更新置零算法.新算法不仅减少了计算复杂度,同时能保持置零算法的性能.基于实测数据的仿真结果验证了新算法的有效性.%Crosstalk is the major factor affecting the transmission performance of the VDSL2 system. Most of the existing crosstalk cancellation algorithms are used when the number of the users remains unchanged. In actual access environment, the old users often are offline or the new users are on-line, causing changes of crosstalk environment. In this paper, by using matrix elementary transformations and matrix partition, we propose a novel method to update the Zero-forcing cancellation method as the old users get offline. The new algorithm dramatically reduces the computational complexity of the original Zero-forcing algorithm while maintaining the same performance. Simulation results based on measured data demonstrate the effectiveness of the algorithm.