To simplify a transmitter and a receiver and to realize an excellent synchronization characteristic and an excellent transmission line estimate characteristic even under a communication environment with a large noise power.

This transmitter is provided with an M sequence generating section 11 that generates an M sequence S11 excellent in an autocorrelation characteristic by a correlation calculation of the same signal on a time base, a time → frequency conversion section 12 that converts the M sequence S11 into a frequency sequence S12, a signal point mapping section 13 that selects a signal point closest to the frequency sequence S12 among signal points that can be taken by a prescribed modulation system within available frequencies an generates a signal sequence S13 mapping the frequency sequence S12 onto the selected signal point, and a frequency → time conversion section 14 that uses the signal sequence S13 to generate a synchronization signal sequence S14 on the time base.