An automatic H-register clear system for the prevention of erroneous convolution in adaptive digital echo cancellers is disclosed. Incoming signals from the H-register are accumulated and compared to a predetermined threshold value and when the value is exceeded, the H-register is cleared with the occurrence...http://www.google.com.tw/patents/US4021623?utm_source=gb-gplus-share專利 US4021623 - Automatic H-register clear for prevention of erroneous convolution in digital adaptive echo canceller
