Apparatus and method for optimally compensating for imbalance between in-phase and quadrature-phase in a zero-IF OFDM receiver

摘要

An optimum I/Q imbalance compensating apparatus and method in a zero-IF OFDM receiver. In the apparatus, a first compensator generates a first symbol by removing interference from a second distorted symbol on an (N_s−m+1)^th subcarrier from a first distorted symbol on an m^th subcarrier by a first compensation coefficient in an OFDM FFT signal of N_s subcarriers. A first hard decider generates a first compensated symbol by hard-decision on the first symbol, an error calculator generates an error symbol by subtracting the first received symbol from the first compensated symbol. A second compensator generates a second symbol by eliminating interference from the first distorted symbol from the second distorted symbol using a second compensation coefficient. A second hard decider generates a second compensated symbol by hard-decision on the second symbol, and an adaptive controller updates the first compensation coefficient using the error symbol and the second compensation symbol.