Patent ID: 7463733

Claim:
An interference cancellation method for use in a fixed communications system in which a plurality of communication paths are arranged to transmit and receive respective analogue signals, the communication paths being such that signals transmitted on one path interfere with signals received on another path, the method comprising: effecting an initialization phase, during which test signals are transmitted, to calculate, for each path, interference effects of the signals transmitted on that path on the signals received on each of the other paths, and storing for each path a plurality of weighting factors (ω 0 −ω n−1 ) representing the interference on each of the other paths respectively, wherein in the initialization phase a timing value (τ 0 −τ n−1 ) is stored with each weighting factor representing the effective relative delay of the interference signal on each path; and during transmission of communication signals, using said weighting factors and respective timing values to generate from the transmitted signal on one of said paths, a cancellation signal for each of the other paths and applying said cancellation signal to signals received on said other paths thereby to cancel the interference effect of said transmitted signal.