Patent ID: 7623595

Claim:
A method for filtering an input signal, the method comprising: receiving, at an apparatus, a first demodulated signal produced by multiplying a first generated signal with a received input signal, the first generated signal being of a form cos(w c t) with w c being a carrier frequency; receiving, at the apparatus, a second demodulated signal produced by multiplying a second generated signal with the received input signal, the second generated signal being of a form α sin(w c t−φ), wherein α represents an amplitude mismatch and φ represents a phase mismatch between the first and second generated signals; obtaining one or more groups generated from one or more previously received input signals, respectively, wherein each group comprises a first demodulated signal and a second demodulated signal, wherein each previously received input signal comprises two signals that differ in phase; generating a filtering coefficient for each obtained group, wherein each generated filtering coefficient comprises a matrix comprising one or more non-symmetrical terms; and producing first and second filtered output signals by applying a first filtering coefficient to the first and second demodulated signals, wherein the first filtering coefficient comprises a matrix comprising one or more non-symmetrical terms, wherein producing first and second filtered output signals further comprises applying the one or more generated filtering coefficients to the one or more obtained groups.