| 摘要 |
PROBLEM TO BE SOLVED: To compensate IQ imbalance by estimating an amount of mutual interference between paired subcarriers due to IQ imbalance of an orthogonal modulator without using a specific preamble signal. SOLUTION: An OFDM signal includes first OFDM symbol and a second OFDM symbol each having a first transmission pilot signal and a second transmission pilot signal allocated to the paired subcarriers located symmetrically on a frequency axis; and is non-zero in a difference between a product of a first transmission pilot signal and a complex conjugate of a fourth transmission pilot signal and a product of a third transmission pilot signal and a product of a complex conjugate of a second transmission pilot signal. Influences of amplitude error and phase error are compensated with respect to a received OFDM signal by transmitting the OFDM signal, extracting first and second received pilot signals corresponding to a first subcarrier into intervals of the first and second OFDM symbols in the received OFDM signal on a receiving side, estimating coefficients representing change components and interference components of an amplitude and a phase produced in each carrier, and estimating IQ imbalance characteristics produced on the OFDM signal at the time of orthogonal modulation from each coefficient. COPYRIGHT: (C)2008,JPO&INPIT
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