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.
Original language | English (US) |
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Pages (from-to) | 915-926 |
Number of pages | 12 |
Journal | Journal of Optical Networking |
Volume | 5 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2006 |
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Computer Science Applications
- Computer Networks and Communications
- Electrical and Electronic Engineering