| 摘要 |
The present invention relates to echo cancelling techniques and more particularly to an initialization device for an echo cancelling system. The invention comprises means for converting a pseudo-random sequence (uk) of length N into a sequence of emitted samples (ek) such that each sample ek is derived from uk by ek=2 uk-1, multiplying each sample u(N-M+1+k)mod N with each received sample sN+k and adding the results k varying between 0 and N-1. The result at instant kT, to within a multiplicative constant, of said additions is then HM(k), one of the N coefficients at the initial conditions of said echo cancelling device, M being between 0 and N, and k varying from 0 to N-1, with HM (k)=HM (k-1)+sN+k. u(N+k+1-M)mod N. The invention is applicable to the pulse response of any signal. |
