Quality of Service Improvement in Optical Code Division Multiple Access Networks

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Shoaie, Mohammad Amin | 2011

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Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 41867 (05)
University: Sharif University of Technology
Department: Electrical Engineering
Advisor(s): Pakravan, Mohammad Reza
Abstract:
In this thesis we have studied slotted and unslotted ALOHA random access optical CDMA packet switching networks with a chip-level receiver structure. We used generalized optical orthogonal codes (GOOC) and Overlapping PPM (OPPM) signaling technique to improve system performance. The impact of physical layer parameters such as GOOC code cross correlation value and OPPM overlapping index on key performance benchmarks such as network throughput and delay are analyzed. We have also studied the stability of the network based on the number of backlogged users, using expected state drift. It has been shown that using GOOC instead of strict OOC improves the network average delay and throughput. Moreover by comparing M-ary OPPM and conventional OOK signaling with a fair criterion we have demonstrated that OPPM signaling can substantially improve both steady state and transient network characteristics. This improvement can be obtained without introducing additional complexity in the receiver structure
Keywords:
Optical Code Division Multiple Access (OCDMA) ; Service Quality ; Normalized Throughput ; Pulse Position Modulator ; Generalized Optical Orthogonal Code ; ALOHA Network ; Channel Access Delay

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