Impact of encoder-decoder wavelength mismatch on the performance of direct-sequence optical code-division multiple-access system

The impact on the performance of the direct-sequence optical code-division multiple-access (DS-OCDMA) system due to wavelength mismatch between encoder and decoder is investigated. Simulation results show that the encoder-decoder wavelength mismatch will degrade the bit-error-rate performance of the DS-OCDMA system drastically by decreasing the contrast ratio of the correctly and incorrectly decoded signals and lower data rate systems are more vulnerable to wavelength mismatch than higher data rate systems. In practical DS-OCDMA systems, the wavelength mismatch between encoder and decoder should be minimized, and some protective measures, such as temperature stabilization and fiber Bragg grating (FBG) packaging, should be taken to enhance the immunity of the superstructured FBG encoder/decoder to ambient conditions. (c) 2007 Society of Photo-Optical Instrumentation Engineers.