RADIO EQUIPMENT AND TRANSMISISON METHOD

摘要

PROBLEM TO BE SOLVED: To realize a modulation system for conducting the reception of high sensitivity in a digital modulation system used for radio communication. SOLUTION: A BPSK modulation system is periodically inserted instead of a pilot symbol and a signal point position in the inphase/orthogonal plane of the BPSK modulation system is arranged in a position different from a signal point taking the maximum amplitude of a multivalue modulation system Thus, the signal point amplitude of the BPSK modulation system is made to be larger than the maximum signal point amplitude of the multivalue modulation system without affecting the ratio of peak power to average transmission power. Thus, the estimation precision of frequency offset and amplitude distortion quantity between a transmitter and a receiver when quasi-synchronous detection is conducted on a demodulation side improves. A bit error rate characteristic in the radio of carrier power to noise power improves and the reception of high sensitivity can be conducted.