System for enhancing an analog signal

摘要

PCT No. PCT/US91/00044 Sec. 371 Date Jul. 9, 1993 Sec. 102(e) Date Jul. 9, 1993 PCT Filed Jan. 11, 1991.A system for enhancing an analog signal by eliminating undesired portions of a detected signal, such as incoherent, background noise is disclosed. A detected input signal is divided into two paths (P1 and P2), each path having a high pass filter (50, 52) for removing low frequency noise components beneath the frequency band of the desired portion of the input signal. One signal path (P2) is delayed by a predetermined time delay (54) and summed in a summer (56) with the other signal path (P1). By shifting and summing the two path signals, the desired signal is enhanced in a number of ways. First, the incoherent, undesired portions of the detected signal within the frequency band may be significantly attenuated or cancelled. Second, the gain of the desired portion of the detected signal is increased. Third, the quality of the desired signal is improved with the addition of a reverberation component. A low pass filter (58) is used to remove any residual signals above the voice band.