Optical CDMA.

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Optical CDMA Exhibited by: George Partasides http://partasides.da.ru Diagram History Review (CDMA) 1938, in the field of radar frameworks, illustrations of recurrence bouncing sign examples were protected
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Optical CDMA Presented by: George Partasides http://partasides.da.ru

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History Overview (CDMA) 1938, in the field of radar frameworks, cases of recurrence jumping sign examples were protected During and after WWII the truth of BW development without heartbeat narrowing could likewise give better time determination. 1950s Sol Golomb first Books on CDMA Early framework are ARC-50 by Magnavox and satellite radios and additionally few GPS frameworks

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History Overvirew (Optical CDMA) Relatively new method in Optical Fiber interchanges and appears to outflank conventional TDM and WDM First connected in mid 1980’s by A.Salehi Prucnal and a few others. Go for Terabit execution on Broadband Networks by diminishing the expense of each perspective in optical system.

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Introduction CDMA utilized broadly as a part of radio recurrence correspondence frameworks, particularly in 2G and 3G cell phone systems. Essential Advantage is the way it handles a limited BW among an expansive number of clients (more clients can transmit the same information over the same Bandwidth)

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…introduction (examination) TDMA and WDMA plans present noteworthy disadvantages in Local Area Systems when huge number of clients must be considered. TDMA: one client tx at once  System limit = clients * tx rate WDMA: Four wave blending as examined (next slide)

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Drawbacks DWDM (returned to) Dispersion Attenuation Four wave blending Non-direct nature of refractive file of optical fiber Limits channel limit of the DWDM System Difficult to develop for element set of various clients in view of the critical measure of coordination among the hubs needed for fruitful operation.

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…comparison Optical CDMA does not need time and recurrence administration in light of the fact that every one of the clients transmit utilizing the entire BW in the meantime! It can likewise work nonconcurrently (as in remote applications) without parcel impacts. Space designation necessities are not required here in inconsistency to TDMA and WDMA

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…comparison (Advantages) Simple usage, utilizing existing fiber systems Reduce the expense in each angle: Equipment , outside plant Facilities , Operational Support frameworks SECURITY Eliminate a large number of middle of the road time-division multiplexing steps needed by SONET

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How does o-CDMA work The rule is the same as in remote application. Every client is doled out a special code (spreading length - L-) which is reproduced by every bit. This code is just known not beneficiary with a specific end goal to demodulate the information. The most imperative part for right recognition is the code. This code must be uncorrelated from different user’s codes and be orthogonal .

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Two optical orthogonal Code with length L = 32 and Î»î± = λ c =1. Orthogonal Code illustration First code is spoken to by putting a heartbeat at the 1 st , 10 th 13 th and 28 th chip positions. Second code is spoken to by putting a heartbeat at the 1 st , 5 th 12 th and 31 st chip positions.

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…how does o-CDMA meets expectations O-CDMA isolates the fiber range into individual codes, all got from a solitary broadband optical source (WDM separates the range into tight optical wavelengths) It is a straightforward 3 – step procedure: Source – Filter – Modulator Filter: Spatial Filter can be thought an optical Bar code (settled or programmable)

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Optical CDMA is a telecast innovation, with all data heading off to all parts of the system. At the point when a collector is put anyplace on the system with a standardized identification that matches a transmitter, that flag alone is decoded and extricated from the system. The second necessity for an all-optical system, the capacity to monetarily include clients. A basic tap and addition coupler is introduced in the parallel fiber rushed to various clients, and a recipient is introduced at every ending area

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Internet Traffic – The need - The increment of information through system and particularly LANS

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Internet Traffic a few measurements 250% expansion in web activity in our University in one year time!

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References Textbooks Spread Spectrum CDMA Systems for remote Communications (savo Glisic , Branka Vucetic) Spread Spectrum Communications Handbook(Marvin K. Simon, Jim K. Omura, Robert A. Scholtz, Barry K.Levitt) Wireless Network Evolution 2G to 3G (Vijay K. Garg) Links Optical CDMA with Optical Orthogonal Code Effects of Optical Layer Impairments on 2.5 Gb/s Optical CDMA Transmission http://www.tks.buffalo.edu/usg/Public/Mail/Imap-s/Stats/lookup.html http://www.technologie.pl/fiber/zalacznik/artykuly/http://www.technologie.pl/fiber/zalacznik/artykuly/report09981.htm http://telephonyonline.com/ar/telecom_seamless_mobility_real/index.htm .:

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