Autoregressive signal processing for repeater echo cancellation

An apparatus, comprising:

• an adjustable filter;
• and
• processing circuitry coupled to the adjustable filter, the processing circuitry configured to:
• measure an error signal in a signal path of the apparatus, wherein the error signal contains desired communication signals, noise signals, and multipath coupling interference signals;
• compute a power spectrum of the measured error signal;
• estimate a response of the multipath coupling interference by processing the power spectrum of the measured error signal using autoregressive estimation in a frequency domain that is performed using linear prediction in the frequency domain by minimizing, at a discrete set of frequencies, a prediction error power associated with the measured error signal;
• compute a plurality of FIR filter coefficients from the estimated response;
• and
• apply the plurality of filter coefficients to the adjustable filter to generate a cancellation signal used to at least partially mitigate the multipath coupling interference signals.