Patent ID: 6754448
Filing Date: 2004-06-22
Classification: H04J

Abstract:
A multiplex transmission apparatus that converts a plurality of signals varied in phase into an optical signal and, after transmission, extracts a desired signal therefrom, comprising:a signal source for outputting a main local oscillation signal having a predetermined frequency fx; a first delay controller for giving a predetermined time delay &tgr;x to said main local oscillation signal outputted from said signal source and outputting said main local oscillation signal as a first sub-local oscillation signal; a first optical transmitter for converting said main local oscillation signal outputted from said signal source into a first optical signal having a wavelength &lgr;1; second optical transmitter for converting said first sub-local oscillation signal outputted from said first delay controller into a second optical signal having a wavelength &lgr;2; a first optical multiplexer for multiplexing said first optical signal outputted from said first optical transmitter and said second optical signal outputted from said second optical transmitter; a first optical transmission path for transmitting an optical signal outputted from said first optical multiplexer; an optical separator for separating, for each wavelength, the optical signal transmitted through said first optical transmission path and outputting said first and second optical signals; a first multiplexer for multiplexing a first main element signal having a predetermined frequency fa and a second main element signal having a predetermined frequency fb, and outputting a multiplexed signal as a main signal group; a second multiplexer for multiplexing a first sub-element signal obtained by giving a predetermined time delay &tgr;a to said first main element signal and a second sub-element signal obtained by giving a predetermined time delay &tgr;b to said second main element signal, and outputting a multiplexed signal as a first sub-signal group; a first optical modulator for modulating said first optical signal outputted from said optical separator with said main signal group outputted from said first multiplexer; a second optical modulator for modulating said second optical signal outputted from said optical separator with said first sub-signal group outputted from said second multiplexer; a second optical multiplexer for multiplexing said first optical signal outputted from said first optical modulator and said second optical signal outputted from said second optical modulator; a second optical transmission path for transmitting an optical signal outputted from said second optical multiplexer; and an optical receiver for carrying out square-law detection on the optical signal transmitted through said second optical transmission path, and outputting a signal that uniquely corresponds to either one of said first main and sub-element signals and said second main and sub-element signals.