DIGITAL COMMUNICATION pptx

DIGITALCOMMUNICATION  EditedbyC.Palanisamy ȱ ȱȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ Digital Communication Edited by C. Palanisamy Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2012 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. As for readers, this license allows users to download, copy and build upon published chapters even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Marina Jozipovic Technical Editor Teodora Smiljanic Cover Designer InTech Design Team First published March, 2012 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Digital Communication, Edited by C. Palanisamy p. cm. ISBN 978-953-51-0215-1 ȱ ȱ Contents ȱ Preface IX Chapter 1 Principles of Transmission and Detection of Digital Signals 1 Asrar Ul Haq Sheikh Chapter 2 Digital Communication and Performance in Nonprofit Settings: A Stakeholders' Approach 29 Rita S. Mano Chapter 3 Wireless Communication in Tunnels 41 Jose-Maria Molina-Garcia-Pardo, Martine Lienard and Pierre Degauque Chapter 4 MANET Routing Protocols Performance Evaluation in Mobility 67 C. Palanisamy and B. Renuka Devi Chapter 5 Security Limitations of Spectral Amplitude Coding Based on Modified Quadratic Congruence Code Systems 79 Hesham Abdullah Bakarman, Shabudin Shaari and P. Susthitha Menon Chapter 6 Adaptive Blind Channel Equalization 93 Shafayat Abrar, Azzedine Zerguine and Asoke Kumar Nandi Chapter 7 Adaptive Modulation for OFDM System Using Fuzzy Logic Interface 119 Seshadri K. Sastry Chapter 8 Application of the Mode Intermittent Radiation in Fading Channels 139 Mihail Andrianov and Igor Kiselev Chapter 9 Coherent Multilook Radar Detection for Targets in KK- Distributed Clutter 161 Graham V. Weinberg VI Contents Chapter 10 WiMAX Core Network 177 ZeHua Gao, Feng Gao, Bing Zhang and ZhenYu Wu Chapter 11 The WiMAX PHY Layer 195 Marcel O. Odhiambo and Amimo P.O. Rayolla ȱȱ ȱ Preface ȱ ItȱisȱtheȱInformationȱeraȱwhereȱcommunicationȱisȱplayingȱtheȱimperativeȱroleȱinȱhumanȱ raceȇsȱ existence.ȱ Digitalȱ communi cations, ȱ toge therȱ withȱ itsȱ applicationsȱ andȱ growingȱ technologies,ȱisȱamongȱtodayȇsȱmostȱactiveȱareasȱofȱdevelopment.ȱTheȱveryȱrapidȱpaceȱofȱ improvementsȱ inȱ technologyȱ isȱ theȱ ke yȱ enablerȱ ofȱ theȱ aggressivelyȱ escalatingȱ capacityȱ demandsȱ ofȱ emerg ing ȱdigitalȱ communicationȱ systems.ȱWithȱ theȱ parenta lȱsupportȱ fromȱ Digitalȱ Communicationȱ twoȱ other ȱ modesȱ ofȱ co mm unicationȱ areȱ currentlyȱ hypedȱ everywhere,ȱWirelessȱCommunicationȱandȱMobile ȱCommunication.ȱConsequently,ȱthereȱ hasȱ bee nȱ aȱ tremendousȱ andȱ very ȱ widespreadȱ ef fortȱ onȱ theȱ partȱ of ȱ theȱ researchȱ communityȱ toȱ developȱ novelȱ techniquesȱ that ȱ canȱ fulfillȱ thisȱ promise.ȱ The ȱ publishedȱ literatureȱ inȱ thisȱ areaȱ hasȱ grownȱ explosiv elyȱ inȱ rece ntȱ years,ȱ andȱ itȱ hasȱ becomeȱ quiteȱ difficultȱtoȱsynthesi z eȱtheȱmanyȱdevelopmentsȱdescribedȱinȱtheȱliterature.ȱThisȱbookȱisȱaȱ compilationȱofȱtheȱideasȱofȱrenownedȱacademicians,ȱresearchersȱandȱpractitioners ȱinȱtheȱ selectedȱ field.ȱ Theȱ chaptersȱ areȱ selfȱ containedȱ andȱ writtenȱ principallyȱ forȱ designers,ȱ researchers,ȱandȱ graduateȱstudentsȱ withȱsomeȱ prio rȱexposu re ȱtoȱdigitalȱ communi cationȱ systems.ȱTheȱpurposeȱofȱthisȱbookȱisȱtoȱpresent,ȱinȱoneȱplaceȱandȱinȱaȱunifiedȱframework,ȱ aȱnumberȱofȱkeyȱrecentȱcontributionsȱinȱthisȱfield.ȱEvenȱthoughȱtheseȱcontributionsȱcome ȱ primarilyȱ fromȱ theȱ researchȱ community,ȱ theȱ focusȱ ofȱ this ȱ presentationȱ isȱ onȱ theȱ development,ȱanaly sis,ȱandȱunderstandingȱofȱexplicitȱalgorithms.ȱ Basicȱ principlesȱ ofȱ dataȱ transmissionȱ andȱ networkingȱ protocols,ȱ forȱ exampleȱ routingȱ areȱ addressedȱ toȱ someȱ extent.ȱ Thereȱ areȱ aȱ fewȱ chaptersȱ onȱ digitalȱ communicationȱ techniques,ȱmethodsȱandȱmodeȱofȱ propagationȱ ofȱtheȱ digitalȱsignals.ȱWiMax,ȱ anotherȱ allȬinȬoneȱ technologicalȱ conceptȱ toȱ serveȱ yourȱ dayȬtoȬdayȱ demandsȱ allȱ putȱ together,ȱ actually,ȱ standsȱ forȱ Worldwideȱ Interoperabilityȱ forȱ Microwaveȱ Access.ȱ Asȱ widelyȱ knownȱ WiMaxȱ enablesȱ the ȱ deliveryȱ ofȱ lastȱ mileȱ wirelessȱ broadbandȱ accessȱ as ȱ anȱ alternativeȱ toȱ ADSLȱ andȱ Cableȱ broadband.ȱ The ȱ coreȱ architectureȱ ofȱ WiMaxȱ andȱ theȱ structureȱofȱitsȱphysicalȱlayerȱareȱalsoȱpresentedȱtoȱenableȱtheȱreadersȱtoȱexposeȱonȱtheȱ recentȱdevelopment.ȱ ȱ C.ȱPalanisamy,ȱProfessorȱandȱHeadȱ DepartmentȱofȱInformationȱTechnology,ȱ BannariȱAmmanȱInstituteȱofȱTechnology,ȱ Sathyamangalam,ȱTamilnadu,ȱȱ Indiaȱ X Preface Acknowledgmentsȱȱ Iȱwouldȱlikeȱtoȱacknowledgeȱmyȱinstitution,ȱBannariȱAmmanȱInstituteȱofȱTechnology,ȱ Sathyamangalam,ȱ India,ȱ theȱ Honourableȱ Chairmanȱ ofȱ ourȱ instituteȱ Drȱ Sȱ Vȱ Balasubramaniam,ȱandȱOurȱbelovedȱDirectorȱDrȱSȱKȱSundararaman,ȱwhoȱencouragedȱ andȱprovidedȱtheȱnecessaryȱfacilitiesȱtoȱtakeȱupȱthisȱtask.ȱ Iȱ wouldȱ alsoȱ likeȱ toȱ acknowledge ȱ myȱ mentors,ȱ Drȱ Aȱ Mȱ Natarajanȱ andȱ Drȱ Aȱ Shanmugamȱwhoȱencouragedȱmeȱtoȱtakeȱupȱtheȱeditorialȱtaskȱofȱthisȱbook.ȱMoreover,ȱIȱ wouldȱ likeȱ toȱ rememberȱ theirȱ recommendations,ȱ whenȱ dealingȱ withȱ aȱ difficultȱ problem,ȱ revisingȱ theȱ veryȱ basicȱ ideasȱ andȱ principles, ȱ andȱ eventuallyȱ toȱ tryȱ otherȱ approaches,ȱevenȱ partiallyȱorȱfullyȱinnovative. ȱ Iȱwouldȱalsoȱlikeȱtoȱ expressȱmyȱthanksȱ toȱtheȱmanyȱProfessorsȱandȱcolleaguesȱwhoȱgaveȱmeȱconstructiveȱcriticismȱandȱusefulȱ suggestions.ȱ Theyȱ include:ȱ Drȱ Sȱ Selvan,ȱ Drȱ Rȱ Harikumar,ȱ Drȱ Sȱ Ramakrishnan,ȱȱȱȱDrȱ AmitabhȱWahi,ȱMrȱTȱVijayakumarȱandȱOthers.ȱȱ ȱ ȱ [...]... public network in 1992 resulted in an explosive growth of digital communications Currently, digital signaling is ubiquitous in modern communication systems 2 Digital signal transmission and detection A schematic of a generic digital communication system, shown in Figure 1, consists of several blocks Though all blocks are important for reliable communications, our focus inhere will be on three blocks... and making decisions to recover the information signals with minimum probability of error Because of its extensive use of probability and random processes, the study of digital communication is quite abstract The performance of digital communication heavily depends on the way the transmission medium affects the transmitted waveforms The transmission medium alters the signal waveforms during their passage... established are later used to study the performances of several digital communication systems operating over channels that fade and disperse the signal waveforms The channels may also be contaminated by interference - intelligent or otherwise It is interesting to note that the telegraphic system introduced in 1844 was an example of digital communication The long distance telegraphy across Atlantic started... code (signal design) to send digital signals resulted in Baudot code in 1875, which interestingly found application many decades later when teletypewriter was invented After this, the status of digital communication did not make much progress primarily due to the invention of telephone, an analog device, by A G Bell in 1876 This invention led to rapid progress in analog communications with analog voice... 0 1 Principles of Transmission and Detection of Digital Signals Asrar Ul Haq Sheikh King Fahd University of Petroleum & Minerals Saudi Arabia 1 Introduction The subject of digital communications pertains to transmission and reception of digital signals The transmitter functions include periodically choosing a signal out of many possible, converting... blocks are sufficient to establish the principles of digital transmission and detection Digital signals for transmission over a given medium are prepared from the outputs of an information source, which may produce signals in either analog or digital form An analog information bearing waveform is sampled at an appropriate sampling rate and then encoded into digital signal The encoded signal, in general,... of levels is more than two The digital signals are further processed with implementation of source encoding and error control coding before converting them into waveforms that suit the transmission medium Fig 1 A Schematic of a Generic Digital Communication System 2.1 Principles of signal detection and decision hypothesis Let us now deliberate on the fundamentals of digital transmission and reception... TransmissionDigital Signals Principles of Transmission and Detection of and Detection of Digital Signals Equation (5) give an alternate receiver structure, which also delivers optimum decisions The correlation receiver as it is called is shown in Figure 3 The two optimum structures defined above can be used for any signaling format An important question that remains relates to measure of digital communication. .. (z) = √ π ∞ z √ exp(−t2 )dt = 2Q(2 z) (9) 6 6 Digital Communication Will-be-set-by-IN-TECH For binary bipolar transmission, the error probability is obtained as Pe = Q 2E b N0 In the case of unipolar transmission, the error probability is Q( inferior to that of polar signaling (10) Eb N0 ) The performance is 3dB Fig 4 The Error Likelihood for Binary Digital Communications 4 Bandpass signaling So far transmission... find a closed form solution have not succeeded and expressions for error probability bounds are usually derived 14 14 Digital Communication Will-be-set-by-IN-TECH 4.6 Diversity techniques for time varying fading channels The channel fading significantly degrades the performance of digital communication systems Diversity reception implies use of more than one signal replicas with an aim to mitigate effect . emerg ing digital communication systems.ȱWithȱ theȱ parenta lȱsupportȱ fromȱ Digital Communication twoȱ other ȱ modesȱ ofȱ co mm unicationȱ areȱ currentlyȱ hypedȱ everywhere,ȱWireless Communication andȱMobile. communications. Currently, digital signaling is ubiquitous in modern communication systems. 2. Digital signal transmission and detection A schematic of a generic digital communication system, shown. extensive use of probability and random processes, the study of digital communication is quite abstract. The performance of digital communication heavily depends on the way the transmission medium