| 摘要 |
<p>PROBLEM TO BE SOLVED: To calculate a precise delay profile, even if it is of OFDM transmission by the segment system amd also to establish accurate symbol synchronization even under an environment, such as fading. SOLUTION: A 1st symbol synchronization circuit 16 specifies a window position, an FFT circuit 13 applies Fourier transformation to an OFDM signal and frame synchronization is established. In this case, a CP/DBPSK detection/ complex division circuit 19 extracts a phase reference signal of a CP signal and a DBPSK signal in a frame synchronizing head symbol, inserts '0' to other carrier positions to obtain a characteristic of a transmission line through complex division by using a known signal. An IFFT circuit 18 applies inverse Fourier transform to this signal to obtain a delay profile. Based on the delay profile, a 2nd symbol synchronization circuit 17 sets an FFT window the same as the transmitter side or deviated by a prescribed position.</p> |
