Patent ID: 7027466

Claim:
A multiplex communication system comprising: a multiplexer which divides a carrier pulse train having a predetermined amplitude into N pulse trains, modulates said N pulse trains by N data signals, respectively, to produce N modulated pulse trains, and time-division multiplexes said N modulated pulse trains to produce a multiplexed modulated pulse train, said multiplexer comprising an amplitude adjuster which implements an amplitude adjustment so that said N modulated N pulse trains have different amplitudes from each other; and a demultiplexer which comprises a transmitting/blocking section having an input port that receives the multiplexed modulated pulse train, a control signal corresponding to one of the N modulated pulse trains, and an output port that emits said one of the N modulated pulse trains corresponding to the control signal; a reference section which receives the multiplexed modulated pulse train and generates a reference signal representing the average amplitude of pulses in the N modulated pulse trains; a detection section which generates a detection signal with information identifying said one of the N modulated pulse trains that is emitted by the transmitting/blocking section; a judgment section which compares the reference signal to the detection signal and generates a judgment signal; and a control section which generates the control signal for the transmitting/blocking section on the basis of at least the judgment signal and an electrical select signal that designates one of the modulated pulse trains, wherein N is two, and the transmitting/blocking section blocks one of the two pulse trains and transmits the other to the output port of the transmitting/blocking section, and wherein the detection section receives an electrical signal that is generated by the transmitting/blocking section from energy absorbed from the blocked signal.