QUADRATURE FREQUENCY DIVISION MULTIPLEXING SIGNAL TRANSMITTER-RECEIVER

摘要

PROBLEM TO BE SOLVED: To make an accurate synchronizing signal easily obtainable on a receiving side. SOLUTION: A transmitter has an IFFT pilot signal generating circuit 3 which generates multilevel QAM signals, a guard interval setting circuit 4, and a clock signal generating circuit 10 which drives the circuits 3 and 4 and generates a pilot signal which has a high-order frequency and the phase of which is maintained constantly in a plurality of symbol sections. The pilot signal is set in such a way that the signal can exist an integeral multiple of wavelength or by a multiple of an odd number of a half wavelength and the signal can be sent out continuously over a plurality of symbol section including the above-mentioned symbol sections. A receiver generates a clock signal by demodulating the pilot signal.