TRANSMITTER, RECEIVER, TRANSMISSION SYSTEM AND TRANSMISSION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a transmission reception system where much more information can be transmitted with the same frequency band by solving a problem that the transmission information quantity cannot be increased if the transmission frequency band is limited in a transmitter sending a digital signal. SOLUTION: The modulator 4 that conducts m-value QAM modulation in a transmitter 1 assigns the n-value data of a 1st data stream to a signal point group resulting from grouping signal points on a signal space diagram consisting of an n-value 1st data stream and p-value 2nd and 3rd data streams, and the transmitter 1 transmits modified m-value QAM modulation signals. The demodulator 25 of a 1st receiver 23 demodulates the n-value 1st data stream, a 2nd receiver 33 demodulates the 1st and 2nd data streams and a 3rd receiver 33 demodulates the 1st, 2nd and 3rd data streams. Thus, even a receiver having only a demodulation capability of the n-value (n