Coherent OCDMA network based on a new BER performance equalization technique for multimedia applications

This paper presents the methodology of using a new performance equalization technique (PET) in the coherent optical code division multiple access (OCDMA) system for different media services. The existing weighted modified prime code (WMPC) is firstly used in the different-weight variable-length (DW-VL) form to spread the digital bits of the service media provided by the network. This gives different bit error rate (BER) performances according to the service provided. For the purpose of BER performance equalization regardless the type of service media provided, the PET was used with the WMPC in the fixed-weight fixed length (FW-FL) form. Also, the encoding scenario using the DW-VL-WMPC in different media services has been presented in the literature. However, in this study, the FW-FL-WMPC encoding scenario is illustrated for different service media. Here, the multiple access interference (MAI) is considered as a source of noise in the BER analysis with the shot and thermal noises. Moreover, the BER simulation versus the system parameters is illustrated and discussed. Obtained results indicate that the coherent OCDMA system using PET with the FW-FL-WMPC can accommodate different rates at better and equal BER performance in comparison with the system using the DW-VL-WMPC without PET.