Abnormal signal detection and cancellation by using adaptive digital filter

Recently, the detection of a noise component added in a transmission line and a signal component buried in a noise have become important problems. an adaptive predictor using an adaptive digital filter (ADF) is effective in cancelling the noise component in the input signal, especially when the statistical property of the noise is unknown. In addition, it can operate at high speed because of its simplicity. the conventional adaptive predictor using ADF can detect the existence of an abnormal signal. However, it cannot detect its accurate waveform because of an occurrence of echo caused by the abnormal signal. Therefore, the conventional system cannot cancel the abnormal signal. In this paper, a novel system is proposed to cancel an abnormal signal in an input signal by using an adaptive predictor with a decision feedback. First, the cause of the occurrence of echo in the conventional predictor is shown. Next, the behavior of the new system is explained. Then a more accurate canceller of the abnormal signal with the two cascade‐connected ADFs is shown.