| 摘要 |
PURPOSE:To allow the demodulator to flexibly cope with increase/decrease in number of carriers demodulated simultaneously without increasing the circuit scale. CONSTITUTION:The demodulator is provided with an orthogonal frequency conversion means 101 receiving a signal including a modulation signal of plural carriers to obtain I and Q components, an A/D converter 103 for signals of each component, a time division multiplex processing frequency shift means 105 applying time division-receiving outputs of the D/A converters 103 by number of carriers to be demodulated so as to shift the frequency of the modulation signal resulting in being a base band signal whose center frequency is 0 and using the result as a time series output corresponding to each carrier, a low pass filter means 106 extracting only the base band signal respectively from the obtained I, Q component signals, an identification discrimination means 107 providing an output of a decoded code according to the identification discrimination system corresponding to the modulation system from the base band signals of the I, Q components, and a demultiplexer 108 demultiplexing the decoded code into each data series and providing an output. |
