Abstract: A wired spread spectrum communication device, a method for communication thereof and a wired spread spectrum communication system capable of enabling easy establishment of synchronism are disclosed. In a transmitter unit of the wired spread spectrum communication device, a spreading code generator generates spread spectrum signals that are based on specified spreading codes, a strobe signal generator and a timing gate output the spread spectrum signals as sync signals at specified timings, and an adder superposes the sync signals to the spread information signals, while the adder further sends the information signals that have been superposed with the sync signals as transmitting signals to transmission paths.

Abstract: A signal superposing apparatus designed, in accordance with a basic power line model taking account of the term of the mutual inductance and that of a self inductance of a transformer connected to AC power lines, with the circuit constants of capacitors selected appropriately to minimize the distortion of information waveform by the effect of the impedance of the transformer, will permit any desired waveform to be superposed over power signals with its distortion being kept to the minimum. In this way, for example a stepwise pulse waveform can be superposed over power signals with the distortion of waveform being minimized, and accordingly CDMA is made possible in a power line carrier system whereby information signals are communicated with power signals on AC power lines being used as carrier wave.