Digital I/Q imbalance compensation in a quadrature receiver

For use in a wireless communications network, a receiver configured to reduce distortion in a processed signal, the receiver comprising:

• a pair of quadrature receiver paths configured to process a received analog signal into a processed digital signal;
• a conjugate circuit configured to identify a conjugate of the processed digital signal;
• an adaptation module including a filter bank, the adaptation module configured to identify a set of weighting factors for one or more frequencies of the conjugate of the processed digital signal based on frequency dependent distortion identified using the filter bank;
• a weighting module configured to apply the set of weighting factors to the conjugate of the processed digital signal to form a weighted signal and subtract the weighted signal from the processed digital signal to reduce the distortion, wherein the weighting module comprises a finite impulse response (FIR) filter including one or more taps based on a receiving mode of the receiver, and wherein the adaptation module is further configured to identify complex correlation statistics from an input into a decoder and adapt coefficients of the FIR filter using an adaptation algorithm;
• and
• the decoder configured to decode the processed digital signal.

A method for reducing distortion in a processed signal in a receiver in a wireless communications network, the method comprising:

• receiving an analog signal;
• processing the analog signal into a digital signal using a pair of quadrature receiver paths to form a processed digital signal;
• identifying a conjugate of the processed digital signal;
• applying a set of weighting factors to the conjugate of the processed digital signal to form a weighted signal, wherein applying the set of weighting factors to the conjugate of the processed digital signal comprises:
• identifying frequency independent distortion for one or more ranges of frequencies in the processed digital signal using a filter bank including one or more filters based on a receiving mode of the receiver;
• and
• applying the set of weighting factors to the one or more ranges of frequencies of the conjugate of the processed digital signal based on the frequency independent distortion identified to form a frequency dependent weighted signal as the weighted signal to be subtracted from the processed digital signal;
• and
• subtracting the weighted signal from the processed digital signal to reduce the distortion.