To provide a communication system which is applicable to vehicle-to-vehicle communication.
Data D of 6N bit unit are subjected to BPSK modulation up to an Nth bit, subjected to QPSK modulation up to a 2N-th bit, subjected to 16QAM modulation up to a 4N-th bit, and subjected to 64QAM modulation over 6N bits as a whole. In each case, modulated signals of N symbols are subjected to spread modulation, collected as one multiplex signal and transmitted. At a receiver Rx, the transmitted signals are demodulated by using a corresponding spreading code and demodulated, respectively. Under a proper propagation environment, 6N-bit output from a 64QAM demodulator 840 are subjected to post-stage processing. As the propagation environment becomes worsenes, 4N-bit output from a 16QAM demodulator 830, 2N-bit output from a QPSK demodulator 820 and N-bit output from a BPSK demodulator 810 are subjected to post-stage processing, in this order.
MITA KATSUSHI
SHIBATA TSUGUYUKI
ITO NOBURO
IWANAMI YASUNORI
OKAMOTO EIJI
TSUCHIYA YUI
NAGOYA INST TECHNOLOGY