| 摘要 |
PROBLEM TO BE SOLVED: To solve the problems that there is a fixed limit in much more accuracy improvement since the amplitude characteristic difference or phase characteristic difference of I signal and Q signal becomes the direct cause of code error and that a characteristic change can not be corrected while a reference signal is not transmitted. SOLUTION: On the transmitting side, the known reference signal is transmitted by a specified carrier wave among plural carrier waves composing an OFDM signal, the carrier wave for transmitting the known reference signal is designated by a symbol number to be transmitted by a prescribed carrier wave, and the reference signal is transmitted while being successively and cyclically changed at the interval of a fixed period. On the receiving side, the reference signal is demodulated by a demodulation circuit 311 and transmission line characteristics are detected by a detecting circuit 312. A first correction expression is calculated from the detected transmission line characteristics and stored by a first correction expression deriving and holding circuit 313. The signal is decoded by a first correcting circuit 314 while using this correction expression. Further, the output signal of this correcting circuit 314 is corrected by newly calculating a second correction expression so that high-speed change characteristics can be corrected. |
