EKKO-OPPHEVELSESSYSTEM OMFATTENDE EN EKKO-OPPHEVELSESINNRETNING

• Main Authors: VERDIERE, JEAN-MARC MARIE COLIN DE, LANGLOIS, PATRICE RENE
• Format: Patent
• Language: Norwegian
• Published: 21.10.1987
• Edition: 4
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

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.