IQ Mismatch Compensation Using Adaptive Decorrelation in a Low-IF Receiver in 90

Abstract

We present a single multiplier based adaptive I/Q mismatch compensation circuit for narrowband quadrature receivers. Adaptive decorrelation between I and Q channel data is used for correcting gain and phase mismatches. Adaptation step size is computed from /76/49-norm inverse power measurement and a gear-shifting mechanism is used that allows fast initial convergence and slow adaptation on actual burst data. Image re- jection ratio in excess of 50 dB is reported for GSM receiver after compensati