| 摘要 |
PROBLEM TO BE SOLVED: To estimate a frequency offset even when the ratio of receiving carrier power to noise power is low. SOLUTION: A complex symbol series 13, i.e., the product of conjugate complexes of a complex demodulation symbol sequence 1 detected through quadrature lection and a known symbol series 2, is provided to phase rotation sections 4a, 4b and 4c, where the phase of the complex symbol series 13 is varied based on frequency offsets fa, fb and fc. N symbol adding sections 5a, 5b and 5c add the values which are inputted from the phase rotating sections 4a, 4b and 4c for N symbols, M power adding sections 6a, 6b and 6c calculate the power of values inputted from the N symbol adding sections 5a, 5b and 5c M number of times. A frequency offset control section 7 controls the frequency offsets being fed to the phase rotation sections 4a, 4b and 4c, based on three power sums inputted from the M power-adding sections 6a, 6b and 6c and outputs an estimated frequency offset value 8. |
