Certain Investigations On Error Rate And Outage Analysis Of Polar Coded Incremental Hybrid Relaying Techniques

Abstract

Recent wireless standards are the candidate technologies to fulfill theever increasing data rate demands in wireless cellular networks. Compared tothe previous release of 3GPP community, the Fourth Generation (4G) standardintroduces the deployment of Relay Nodes (RNs) in order to improve the radiocapacity,toenlargethecellcoverageandtoincreasecell-edgethroughput.It provides system bandwidth beyond 20 MHz. The next generation cellularsystemspecifiesspectrumallocationsofupto100MHzusingcarrieraggregationtechniquewheremultiplecarriercomponentsarecombined.Itaddsfeature functionality and performance enhancements to current standard andpromotes better experience. The key next generation wireless communicationsystemsincludeWaveformgenerationtechniques,MassiveMIMOenhancementsandrelaying.Relayisakeyenablingtechnologywhichenablesnextgenerationnetworksto improve the performance in terms of coverage and capacity. Relaying hasbeen identified as an efficient technique to provide cooperative diversity andschemessuchasAmplify-and-Forward(AF),Decode-andForward(DF),Compress-and-Forward (CF), Demodulate-and-Forward are normally used inpractice.Lateron,Decode-Compress-Forward(DCF),Decode-Amplify-Forward(DAF)relayingprotocolshavebeenstudiedwithselectivecooperation.Selective cooperation provides higher channel gain based on source-relay link.To improve the system performance in terms of throughput, spectral efficiencyanddatarate,incrementalrelaying schemesareintroduced.Inadditiontotheaboveschemes,thecooperativegaincouldbeimprovedwith the help of incremental hybrid relaying scheme. In this scheme, feedbackmechanism is incorporated to improve the performance of the system.In thisthesis,anIncrementalHybridDecode-Amplify-Forward(IHDAF)relayingschemeisproposed Quality of Service (QoS) like channel and outage capacities. Also, the IHDAFrelaying scheme is integrated with polar code and successive cancellation (SC)decoder, in which the capacity could be further improved. The polar codedIncremental Hybrid Decode-Amplify-Forward (IHDAF) relaying scheme isdesignedusingsingle and multipleantenna configurationsystemsIn the first module, the bit error rate performance and channel capacityof the proposed Polar Coded IHDAF (PC-IHDAF) relaying is analyzed usingsingle and multiple antenna schemes. It is proved that the capacity of proposedPC-IHDAF relaying scheme is getting improved to 23 b/s/Hz as compared totraditionalAF andDFrelayingschemes.Inthenextmodule,theproposedIHDAFrelayingschemeisextendedtomulti-relay environment. In multi-relay scenario, Polar Coded OpportunisticIHDAF(PCOR-IHDAF)consideredtoinvestigatetheeffectofoutageprobability and outage capacity using Marcum-Q function. The conventionalrelaying schemes such as AF and DF relaying schemes are compared withproposed PCOR-IHDAF scheme. It is observed through simulation that theoutage capacity is increased to 45 b/s/Hz in 8x8 MIMO environment and it ishigherthanAFandDF relaying schemes.Inthethirdmodule,thelauricellahypergeometricfunctionisconsideredtoderivethelevelofErrorVectorMagnitude(EVM)inPCOR-IHDAFenvironment. The different combining schemes such as Equal Gain Combining(EGC), Selection Combining (SC), and Maximal Ratio Combining techniques(MRC) have been compared. From the simulation results, it is seen that theMRCtechniquehastheEVMlevel-27.847dBmwhichissuperiortoEGCandSCschemes.Further,theperformancecharacteristicsintermsofpowerspectrumandpropagationtimeisanalyzedusingPCOR-IHDAFrelayingprotocol.Itisinferredthatthescattermotionisverylessat-100dBmofcarrierfrequency6GHz.