| 摘要 |
<p>There is provided a CDMA communication system in which the number of multiple user stations can be greatly increased under fast fading circumstances. In a transmitting apparatus, an M-ary digital modulator (4) modulates the m-bit (m >/= 2 and m is an integer) binary digital signal into M-value symbols (M = 2<m>) prior to the spreading operation by multipliers (6) and (8). In a receiving apparatus, after the despreading operation by an orthogonalizing filter (56), an M-ary digital demodulator (60) compensates the variation of the phase and amplitude of the carrier of the M-ary modulated signal. A decision circuit (62) decides the output of the M-ary digital demodulator (60). A tap coefficient control circuit (58) calculates orthogonal coefficients using the outputs of the subtractors (64) and (66), the outputs of the M-ary digital demodulator (60), the outputs of receiving filters (52) and (54), and the spreading code (93). The symbols outputted from the decision circuit (62) is converted into an m-bit signal and then combined into a signal of one sequence. <IMAGE></p> |
