A wireless repeater has a receiving antenna for receiving an input signal and a transmitting antenna for transmitting an amplified signal where the input signal is a sum of a remote signal and a feedback signal. The repeater includes an echo canceller receiving the input signal and generating an echo cancelled signal by estimating a feedback channel between the transmitting antenna and the receiving antenna and cancelling a feedback signal estimate from the input signal, an amplifier for amplifying the echo cancelled signal and providing the amplified signal to the transmitting antenna, and a variable delay element receiving the echo cancelled signal and introducing a first delay to the echo cancelled signal. The first delay is selected to optimize the estimation of the feedback channel, thereby optimizing the cancellation of the feedback signal. The delayed echo cancelled signal is coupled to the echo canceller as a reference signal for estimating the feedback channel.