一种新的多重回波抵消的自适应算法

New Adaptive Algorithm for Multiple Echo Cancellation

为了抵消时延很大的多重回波信号 ,回波抵消器需要有大量的抽头 ,抽头系数更新的计算量很大 ,降低了收敛速度。为此提出一种新的自适应算法 ,它是一种针对多重回波的特点 ,在 RLS算法基础上的改进算法 ,它并不需要对所有的抽头系数进行更新 ,而是仅选择其中一部分的系数进行更新。此外 ,还提出了选择所需更新系数的系数窗搜索算法。新算法只用更新一少部分的系数 ,因此它的收敛速度加快了 ,计算量大大减小了。

To cancel multiple echos with long delays, the number of tap coefficients of echo canceller must be large, and it has a very high computational effort for the update of tap coefficient as well as a decreased convergence speed. Thus a new adaptive algorithm has been presented. It is a improved version of RLS algorithm according to the characteristics of multi-echo path. It does not update all coefficients and only updates some selected coefficients. In addition, it presents a coefficient-window searching algorithm to determine which coefficients should be updated. Because of fewer coefficients updated in the new algorithm, the convergence speed increases and the computational effort decreases significantly.