Patent ID: 8594212
Filing Date: 2013-11-26
Classification: H04L

Abstract:
1. A method implemented in a communication receiver for processing a received Orthogonal Frequency Division Multiplexing (OFDM) wireless communication signal, the method comprising: applying frequency offset compensation to produce a frequency offset compensated received signal, wherein the frequency offset compensation comprises digital rotation; determining one or more adjustment values associated with the frequency offset compensation, wherein each of the one or more adjustment values is a complex number associated with an OFDM-symbol of the received OFDM signal, wherein the complex number is a doubling of the phase of the digital rotation corresponding to a particular sample of the OFDM-symbol; transforming the frequency offset compensated received signal to a frequency domain, wherein the frequency domain comprises a plurality of sub-carrier frequencies; estimating an in-phase/quadrature imbalance (IQ-imbalance) based on at least the one or more adjustment values, one or more pieces of information related to a first symbol of a first sub-carrier frequency, and one or more pieces of information related to a second symbol of a second sub-carrier frequency, wherein the second sub-carrier frequency is a mirror sub-carrier frequency to the first sub-carrier frequency, said estimating comprising multiplication with a conjugate function of the complex number; and performing IQ-imbalance compensation of the received OFDM signal based on the estimated IQ-imbalance.