Patent ID: 7649832

Claim:
A wireless communication method comprising: generating an OFDM signal containing a first OFDM symbol having a first transmitting pilot signal and a second transmitting pilot signal respectively allocated to a first subcarrier and a second subcarrier being symmetric with respect to a center frequency on a frequency axis, and a second OFDM symbol having a third transmitting pilot signal and a fourth transmitting pilot signal known to the transmitting side and the receiving side respectively allocated to the first subcarrier and the second subcarrier, a difference between a product of the first transmitting pilot signal and a complex conjugate of the fourth transmitting pilot signal and a product of the third transmitting pilot signal and a complex conjugate of the second transmitting pilot signal being non-zero; transmitting the OFDM signal after applying a quadrature modulation; receiving the transmitted OFDM signal to output a received OFDM signal; extracting a first received pilot signal corresponding to the first subcarrier in the first OFDM symbol zone of the received OFDM signal; extracting a second received pilot signal corresponding to the first subcarrier in the second OFDM symbol zone of the received OFDM signal; estimating a first coefficient representing a change component of an amplitude and a phase which occur in the first subcarrier, and a second coefficient representing an interference component provided to the first subcarrier by the second subcarrier, using the first received pilot signal and the second received pilot signal; estimating from the first coefficient and the second coefficient an IQ imbalance characteristic uniquely determining an amplitude error and a phase error occurred upon the quadrature modulation of the transmitted OFDM signal; compensating an influence of the amplitude error and phase error for the received OFDM signal in accordance with the IQ imbalance characteristic; and decoding the compensated OFDM signal.