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

An apparatus for optimally compensating in-phase/quadrature-phase imbalance in a zero-intermediate frequency (IF) orthogonal frequency division multiplexing (OFDM) receiver, comprising:

• a first compensator for generating a first received symbol by eliminating an interference component caused by a second distorted symbol on an (Ns−m+1)th subcarrier from a first distorted symbol on an mth subcarrier using a predetermined first compensation coefficient in a received OFDM signal including Ns subcarriers after a fast-Fourier-transform of the OFDM signal;
• a first hard decider for generating a first compensated symbol by performing a hard decision on the first received symbol;
• an error calculator for generating an error symbol by subtracting the first compensated symbol from the first received symbol;
• a second compensator for generating a second received symbol by eliminating an interference component caused by the first distorted symbol from the second distorted symbol using a predetermined second compensation coefficient;
• a second hard decider for generating a second compensated symbol by performing a hard decision on the second received symbol;
• and
• an adaptive controller for updating the first compensation coefficient for the first compensator based on the error symbol and the second compensation symbol.