| 摘要 |
<p>PURPOSE:To provide a transmission/reception system for transmitting much more information with the same frequency band by solving the problem of disabling the increase of transmitting information quantity when the frequency band is limited at the transmitter for transmitting digital signals. CONSTITUTION:A transmitter 1 transmits a transformed n-value QAM modulated signal by allocating the n-value data of a first data column to a signal point group dividing signal points on a space diagram into groups concerning first n-value data column, second p-value data column and third data column while using a modulator 4 for performing m-value QAM modulation. A first receiver 23 demodulates the first n-value data column by using a demodulator 25, a second receiver 33 demodulates the first and second data columns, and a third receiver 43 demodulates the first, second and third data columns. Thus, the transmitter can be provided to demodulate the data of the first n-value data column even with the receiver which is provided with just n-ary demodulating ability (n<m) when the m-value transformed multi-level modulated wave is received.</p> |
