Patent ID: 6891948

Claim:
An echo canceller which forms pseudo-echo signals from reception signals using an adaptive filter, and which subtracts pseudo-echo signals from transmission signals using a subtractor to eliminate the echo component in the transmission signals, and comprising: a holding portion which holds at least one communication frame length's worth of reception signals; a power calculation portion which calculates a power once only for each communication frame, based on the reception signals held in the holding portion; a divider which divides, by the power calculated once only for each communication frame, an echo elimination residue signal for each sample of the communication frame output from said subtractor; and an update portion which updates tap coefficients of said adaptive filter according to output signals from the divider, wherein said power calculation portion calculates, for each communication frame, the reception signal power for the communication frame from samples of reception signals of the communication frame, wherein under prescribed conditions, said power calculation portion uses, in addition to the reception signals of the communication frame for power calculation, the reception signals of the communication frame preceding and/or following the communication frame for power calculation, to calculate the power, and wherein said power calculation portion calculates the power, either from the reception signals of the second half of the communication frame for power calculation and the reception signals of the first half of the communication frame following the communication frame for power calculation, totaling one communication frame length's worth of reception signals, or from the reception signals of the first half of the communication frame for power calculation and the reception signals of the second half of the communication frame preceding the communication frame for power calculation, totaling one communication frame length's worth of reception signals.