Patent ID: 7626921
Filing Date: 2009-12-01
Classification: H04L

Abstract:
1. 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 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; receiving the OFDM signal by using orthogonal demodulation to output a received OFDM signal; extracting a first received pilot signal and a second received pilot signal in a first OFDM symbol zone of the received OFDM signal, the first receiving pilot signal and the second receiving pilot signal respectively corresponding to the first subcarrier and the second subcarrier; extracting a third received pilot signal and a fourth received pilot signal in the second OFDM symbol zone of the receiving OFDM signal, the third receiving pilot signal and the fourth receiving pilot signal respectively corresponding to the first subcarrier and the second subcarrier; estimating from the first received pilot signal and the third received pilot signal a first coefficient representing a change component of each of an amplitude and a phase which are occurred in the first subcarrier; estimating from the second received pilot signal and the fourth received pilot signal a second coefficient representing an interference component provided to the second subcarrier by the first subcarrier; calculating from the first coefficient and the second coefficient a weight to be used for compensating influences of an amplitude error and a phase error occurred in the received OFDM signal upon the orthogonal demodulation; compensating the receiving OFDM signal in accordance with the calculated weight to obtain a compensated OFDM signal; and decoding the compensated OFDM signal.