20130121388 | LOW COMPLEXITY FREQUENCY SELECTIVE IQ MISMATCH DIGITAL RX BALANCER AND TX INVERSE BALANCER FOR NON-IDEAL RF FRONT-END - A system for reducing a mismatch between an in-phase (I) signal and a quadrature phase (Q) signal is disclosed. The system includes a phase compensation block comprising an infinite impulse response (IIR) filter configured to reduce a first portion of a mismatch between an I signal and a Q signal, wherein the first portion includes frequency selective phase mismatch. The system further includes a gain compensation block comprising a finite impulse response (FIR) filter configured to reduce a second portion of the mismatch, wherein the second portion includes frequency selective gain mismatch. The phase compensation block and the gain compensation block are calibrated at least in part based on a loopback signal, wherein the loopback signal is routed from a transmitting portion of a radio frequency (RF) circuitry back to a receiving portion of the RF circuitry. | 05-16-2013 |