Demultiplexing device, multiplexing device, and relay device

A multiplexing device that multiplexes input signals corresponding to 2N waves (N is a natural number equal to or larger than one), the multiplexing device comprising:

• a transmission-channel filter group including 2N transmission channel-filter units that waveform-shape the input signals according to a desired frequency characteristic and output the signals;
• a transmission low-pass-filter group including 2N+1−2 transmission low-pass-filter and frequency-converting units that interpolate the waveform-shaped signals to obtain a sampling rate twice as high as a data rate of an input signal, then perform a low-pass filtering process and a frequency converting process for causing the signals to pass through desired bands, and output the processed signals, having the transmission low-pass-filter and frequency-converting units arranged in a tournament with an N-stage configuration, having 2N transmission low-pass-filter and frequency-converting units at a first stage connected to the transmission channel-filter units in a one-to-one relation, and inputting each signal obtained by performing an adding process for each combination of two output signals in adjacent bands from 2(N−M+1) transmission low-pass-filter and frequency-converting units arranged at an Mth (1≦M≦N) stage to a different transmission low-pass-filter and frequency-converting unit at a subsequent stage;
• 2N−1 adding units that perform an adding process for signals output from two transmission low-pass-filter and frequency converting units having desired bands adjacent to each other;
• a filter-bank control unit that generates a clock control signal for supplying a clock to transmission channel-filter units, transmission low-pass-filter and frequency-converting units, and adding units corresponding to signal passage bands, based on channel information estimated from the reception signal;
• and
• a transmission-clock supply unit that supplies a clock to transmission channel-filter units, transmission low-pass-filter and frequency-converting units, and adding units corresponding to the signal passage bands, based on the clock control signal.