Patent ID: 8503926

Claim:
A method in an interference cancellation repeater implemented using a zero-IF receiver and a zero-IF transmitter, the method comprising: receiving an input signal at a first antenna of the interference cancellation repeater, the input signal being a sum of a remote signal to be repeated and a feedback signal resulting from a feedback channel between the first antenna and a second antenna; cancelling a feedback signal estimate from the input signal to generate an echo-cancelled signal; delaying the echo-cancelled signal to generate a reference signal; generating a numerator value from the echo-cancelled signal; generating a denominator value from the input signal or the reference signal or both; generating a metric being a ratio of the numerator value to the denominator value, the metric being indicative of an IQ imbalance in the interference cancellation repeater's receiver and/or transmitter; and compensating for the IQ imbalance in the interference cancellation repeater's receiver and/or transmitter by applying an adaptive algorithm using the metric.