Digital communications receiver and method of estimating residual carrier frequency offset in a received signal

摘要

A carrier frequency offset can be present in a signal received by a communications receiver when the receiver has a local frequency oscillator that generates a carrier frequency different from a carrier frequency generated by a local frequency oscillator at a transmitter that transmitted the signal. A residual carrier frequency offset can remain after most of the carrier frequency offset has been removed from the received signal using conventional techniques. The residual carrier frequency offset is estimated using first and second channel impulse responses derived from first and second portions of the received signal. An estimated phase difference between the first and second channel impulse responses is computed. An estimate of the residual carrier frequency offset is computed using the estimated phase difference.