The algorithm USES an adaptive filter to track the echo path, and an auxiliary filter to cancel the echo together with the adaptive filter.
该算法使用自适应滤波器跟踪回声信道，使用一个辅助滤波器和自适应滤波器一起完成回声消除。
2
The excavation technique consists of main operations including breaking, loading, haulage and support, and auxiliary work including ventilation, laying the track, digging ditches and laying pipes etc.