| 摘要 |
PROBLEM TO BE SOLVED: To control a local oscillation frequency with high accuracy without being affected by fading by a extracting a frequency error component whose frequency error component due to fading is negligible and allowing an oscillator frequency of a local oscillator to follow an oscillator frequency of a transmitter. SOLUTION: Channel estimate sections 11,12 receive a complex reception base band signal to estimate a radio channel circuit and provide an output of channel estimate values 1, 2. Autocorrelation arithmetic sections 21, 22 receive the estimated values 1, 2 to calculate the autocorrelation with the channel estimate values at a time before by a predetermined time and provide an output of channel autocorrelation values 1, 2. An autocorrelation addition arithmetic section 3 adds the autocorrelation values 1, 2 to provide a channel autocorrelation sum, and a control section 4 receiving the sum provides an output of a frequency update amount. Based on the update amount, an oscillated frequency of a carrier signal local oscillator of a receiver is updated. Thus, a multi-path wave is indiyidually processed to enhance the immunity against fading. |
