摘要 |
A complex symbol sequence (13), i.e. the product of a quadrature-detected complex demodulated symbol sequence (1) and the conjugate complex of a known symbol sequence (2), is fed to phase rotating sections (4a, 4b, 4c) where the phase of the complex symbol sequence (13) is varied according to frequency offsets (fa, fb, fc). N symbol adding sections (5a, 5b, 5c) add the values of N symbols inputted from the phase rotating sections (4a, 4b, 4c) and M power adding sections (6a, 6b, 6c) calculate the power of values inputted from the N symbol adding sections (5a, 5b, 5c) and add the power M times. A frequency offset control section (7) controls the frequency offset fed to the phase rotating sections (4a, 4b, 4c) according to the sum of the three powers inputted from the M power adding sections (6a, 6b, 6c) and outputs an estimated frequency offset value (8). |