Patent ID: 8306156
Filing Date: 2012-11-06
Classification: H04L,H04N

Abstract:
1. A receiver, comprising: a frequency offset estimator comprising a modulation removal module to generate a modulation removed signal from received signals and signals generated from known data; and a spectrum inversion detector coupled to the frequency offset estimator to determine whether spectrum inversion has occurred based on an output of the frequency offset estimator, wherein the spectrum inversion detector comprises a comparator to compare an absolute value of the output of the frequency offset estimator and a predetermine threshold, and wherein when the absolute value of the output of the frequency offset estimator is larger than the predetermined threshold, the comparator generates a signal to indicate that spectrum inversion has occurred; an I/Q swap module to swap an in-phase component and a quadrature-phase component, based on an output of the spectrum inversion detector, a direct digital synthesizer coupled with the I/Q swap module to receive input signals and coupled with the frequency offset estimator to provide the received signals to the modulation removal module; and a timing recovery loop to determining symbol boundaries from an output of the direct digital synthesizer; wherein the predetermined threshold is based on a tolerance level of the timing recovery loop.