| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a transmission reception system where much information is sent through a same frequency band by solving a problem unable to increase the transmission information quantity when the frequency band is limited in a transmitter that sends a digital signal. SOLUTION: A modulator 4 conducting m-value QAM modulation in a transmitter 1 transmits a modified m-value QAM modulation signal resulting from assigning n-value data of a 1st data stream to a signal paint group resulting from grouping signal points on a signal space diagram where the 1st data stream of n-value and 2nd and 3rd data streams of a p-value. A demodulator 25 of a 1st receiver 23 demodulates the 1st data stream of n-value, a 2nd receiver 33 demodulates the 1st data stream and the 2nd data stream and a 3rd receiver 43 demodulates the 1st, 2nd and 3rd data streams. Thus, even a receiver having only a demodulation capability of n-value (n<m) in the case of receiving the m-value modified multi-value modulation wave can demodulate data of the 1st data stream of the n-value in the transmitter.</p> |
