Digital time signal filtering method and device for transmission channel echo correction

摘要

PCT No. PCT/FR94/00259 Sec. 371 Date Sep. 8, 1995 Sec. 102(e) Date Sep. 8, 1995 PCT Filed Mar. 9, 1994 PCT Pub. No. WO94/21041 PCT Pub. Date Sep. 15, 1994A method for filtering a time signal (e(t)) sampled in blocks of N samples (e(n),e(k)) uses a transfer function defined in the frequency domain by LN samples (H(K)). The transfer function is filtered by a time window (g1) of width N, and a frequency subsampling of ratio N is performed to give a partial transfer function defined over N samples (H1(k)). The method enables the complexity of circuits operating in real time to be optimized. The technique is particularly suitable for correcting long echoes in television picture receivers.