Optical pulse position modulation processing : Architecture and demonstration in an optical code division multiple access system

Brès, Camille Sophie and Banwell, Tom and Glesk, Ivan and Prucnal, Paul R. and Kwong, Wing C. (2006) Optical pulse position modulation processing : Architecture and demonstration in an optical code division multiple access system. Journal of Optical Networking, 5 (12). pp. 915-926. ISSN 1536-5379

Full text not available in this repository.Request a copy from the Strathclyde author

Abstract

We present a novel architecture for an optical pulse position modulation (PPM) scalable modulator and demodulator with a simple all-optical design based on ultrafast sampling. The use of PPM for two-dimensional time-wavelength incoherent optical code division multiple access (OCDMA) systems is investigated. The shift PPM-OCDMA scheme, where PPM slot overlaps as well as frame overlaps are allowed, is analyzed and compared to the more traditional on-off keying (OOK) and PPM-OCDMA schemes. For our design's parameters, we show that OOK performs better when the network operates at low data-rate transmissions (2.5 GHz or lower) or when the network is small in size. However, our proposed shift PPM-OCDMA outperforms both OOK and PPM-OCDMA when the user's transmission rate increases, relaxing both coding and hardware constraints. An experimental demonstration of shift PPM-OCDMA using our novel PPM modulator and demodulator with four levels was performed. Up to six simultaneous OCDMA users, each operating at 10 Gbits/s, were multiplexed on a star network while operating at a bit error rate of 10-9 or better.