Patent ID: 6731877
Filing Date: 2004-05-04
Classification: H04B

Abstract:
An optical transmission system comprising:a plurality of return-to-zero (RZ) transmitters, each RZ transmitter comprising: a forward error correction (FEC) encoder for receiving a channel input signal and generating therefrom a corresponding FEC encoded output signal; a laser comprising a predetermined frequency which is driven by a predetermined clock signal for generating an optical output signal; and a modulator for modulating the optical output signal from the laser with the FEC encoded output signal from the FEC encoder for generating a channel output signal in a predetermined channel frequency sub-band of an overall frequency band which includes a predetermined channel separation from an adjacent channel frequency sub-band generated by another RZ transmitter; and a multiplexing arrangement for multiplexing the plurality of predetermined channel frequency sub-bands from the plurality of RZ transmitters into separate groups of frequency bands where the groups of frequency bands have a predetermined band-gap separation therebetween wherein each group of frequency bands has a predetermined separate pre-chirp introduced before being multiplexed with all other groups of frequency bands into a single multiplexed output signal.