A wireless repeater includes a receiver circuit implemented as an intermediate frequency (IF) subsampling receiver and a transmitter circuit implemented as a direct conversion (zero-IF) transmitter. The repeater further includes a reference receiver implemented as an IF subsampling receiver to sample a portion of the transmit signal prior to over-the-air transmission for use as the reference signal for channel estimation. Highly accurate channel estimation is obtained by using the reference signal from the reference receiver as the reference signal accounts for distortions in the transmitter circuit of the repeater. The repeater may include an echo canceller to cancel an estimated feedback amount from an input signal based on the channel estimation.