Patent ID: 7321733

Claim:
An optical transmission system comprising: an optical transmitting device for converting an inputted data signal to an optical signal and for transmitting the optical signal to an optical transmission path; and an optical receiving device for receiving the optical signal transmitted via the optical transmission path and for converting the received optical signal to the data signal, wherein: the optical transmitting device includes: a data signal splitting section for splitting information included in the data signal into at least two pieces of information, and for generating at least two respective electrical signals having different center frequencies and bands; a frequency multiplexing section for performing frequency multiplexing of the at least two electrical signals generated by the data signal splitting section so as to generate a frequency-multiplexed signal; and an electrical-to-optical conversion section for converting the frequency-multiplexed signal generated by the frequency multiplexing section to an optical signal and for transmitting the optical signal to the optical transmission path; the optical receiving device includes: an optical-to-electrical conversion section for converting the optical signal transmitted via the optical transmission path to the frequency-multiplexed signal; a band demultiplexing section for demultiplexing the frequency-multiplexed signal output from the optical-to-electrical conversion section to obtain the at least two electrical signals; and a data signal recovering section for recovering the data signal based on the at least two electrical signals demultiplexed by the band demultiplexing section; each of the electrical signals generated by the data signal splitting section are located in different frequency bands which are away from a local minimum of a frequency response of the optical transmission path; and the data signal splitting section includes: a signal splitting section for splitting the information included in the data signal into the at least two pieces of information in accordance with a predetermined split ratio corresponding to the frequency response of the optical transmission path, and outputting the at least two pieces of information as at least two baseband signals, the at least two baseband signals including at least a first and a second baseband signal; and at least one band up conversion section for converting a signal, which contains at least the second baseband signal and excludes the first baseband signal of the at least two baseband signals output from the signal splitting section, to a passband signal having a predetermined frequency as a center frequency, wherein the first baseband signal and the passband signal are output from the data signal splitting section as the generated at least two electrical signals.