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Simulation of a CDMA system based on optical orthogonal codes / Simulering av ett CDMA system baserat på optiska ortogonala koder

<p>To take advantage of the high speed in an optic fiber, one of the basic concept in fiber optic communication is to allow several users to simultaneously transmit data over the channel. One technique that provides multiple access is it fiber optic-code division multiple access (FO-CDMA). In FO-CDMA each user is assigned one or more signature sequences called codewords, which are subsets of a type of optical orthogonal code (OOC). The channel input/output consists of the superposition of several users codewords and at the receiver end an optical correlator extracts the information. </p><p>In the parallel code constructions, presented in this report, each user j is assigned a subset Cj from a code C. The subsets are disjoint and their union is the whole set C. A new way to map the information bits is to insert up to L zeros before each codeword from Cj and let this represent information aswell. This gives high rates for active users but an investigation is needed to ensure that this does not compromise the systems wanted property of sending information with a small probability of errors for all users. Therefore a simulation environment has been implemented in Matlab. </p><p>The result from these simulations shows that BER for the L parallel codes is acceptable and not much higher than for the traditional constructions. Because of the higher rate these construction should be preferred but an analysis if a hardware implementation is possible.</p>

Identiferoai:union.ndltd.org:UPSALLA/oai:DiVA.org:liu-2300
Date January 2004
CreatorsKarlsson, Andreas
PublisherLinköping University, Department of Electrical Engineering, Institutionen för systemteknik
Source SetsDiVA Archive at Upsalla University
LanguageEnglish
Detected LanguageEnglish
TypeStudent thesis, text
RelationLiTH-ISY-Ex, ; 3532

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