BB分布信道下基于網(wǎng)絡(luò)編碼的參數(shù)調(diào)優(yōu)算法

BB分布信道下基于網(wǎng)絡(luò)編碼的參數(shù)調(diào)優(yōu)算法Abstract:Inwirelesscommunicationsystems,thedesignofnetworkcodingschemestoimprovetheperformanceofwirelessnetworksisanimportantresearchtopic.Inthispaper,wefocusontheoptimizationofparametersinthenetworkcodingschemeofawirelessnetworkoperatingonaBBdistributionchannel.Toachieveanefficientnetworkcodingscheme,weproposeaparametertuningalgorithm,whichmaximizesthenetworkcodingthroughputandminimizesthedecodingdelay.Weusesimulationstovalidatetheeffectivenessoftheproposedalgorithm.Introduction:Withthegrowthofwirelesscommunicationsystems,networkcodinghasbecomeaneffectivemethodtoimprovetheperformanceofwirelessnetworks.Networkcodingtechniquesexploitthebroadrangeofavailablefrequenciesandthediversityofwirelesschannelstoincreasenetworkthroughput.Innetworkcodingschemes,packetsareencodedandtransmittedtomultiplereceivers,witheachreceiverabletodecodeitsowntransmittedpackets.Theapplicationofnetworkcodingcanimprovethenetworkthroughputandreducethedelayofpackettransmission.Networkcodingtechniqueshavebeenproposedformanytypesofwirelessnetworks,includingcellular,ad-hoc,anddelay-tolerantnetworks.Oneofthechallengesinthedesignofnetworkcodingschemesistheselectionofappropriateparametersforspecifictypesofwirelessnetworks.Theparametersinthenetworkcodingschemes,includingthenumberofencodingcoefficients,thenumberofdecodingcoefficients,andthemessagesize,arerelatedtotheperformanceofthenetworkcodingscheme.Therefore,itiscriticaltooptimizetheseparameterstoimprovenetworkperformance.Inthispaper,wefocusontheparametertuningofthenetworkcodingschemeforawirelessnetworkoperatingonaBBdistributionchannel.BBdistributionisatypeofwirelesschannelthatexhibitsahigherprobabilityoferrorthanothertypesofwirelesschannels.Therefore,itischallengingtodesignanefficientnetworkcodingschemeforwirelessnetworksoperatingonaBBdistributionchannel.Inthispaper,weproposeaparametertuningalgorithmthatmaximizesthenetworkcodingthroughputandminimizesthedecodingdelayforwirelessnetworksoperatingonaBBdistributionchannel.Inthefollowingsections,wepresenttheproposedparametertuningalgorithmindetailandevaluateitseffectivenessinsimulations.ProposedParameterTuningAlgorithm:TooptimizethenetworkcodingschemeforwirelessnetworksoperatingonaBBdistributionchannel,weproposeaparametertuningalgorithmbasedonthefollowingtwoobjectives:MaximizingthenetworkcodingthroughputMinimizingthedecodingdelayThealgorithmconsistsofthefollowingsteps:Step1:InitializationWeinitiallysetthevaluesoftheparameters,includingthenumberofencodingcoefficients,thenumberofdecodingcoefficients,andthemessagesize.Theinitialvaluesaresettoareasonablevaluebasedonpreviousstudies.Step2:NetworkPerformanceEvaluationWeevaluatethenetworkcodingperformancebasedonthecurrentparametervalues.Thenetworkcodingthroughputanddecodingdelayarecalculatedbasedonthenumberofpacketssuccessfullytransmittedandthetimetakentosuccessfullydecodethepackets.Step3:ParameterUpdateBasedonthenetworkperformanceevaluation,weadjusttheparametervaluestomaximizethenetworkcodingthroughputandminimizethedecodingdelay.Theparameterupdateinvolvesadjustingthevaluesoftheencodinganddecodingcoefficientsandthemessagesize.Thisisdonebyemployinganiterativeoptimizationapproachusinggradientdescent.Step4:RepeatSteps2-3Theabovestepsarerepeateduntilaconvergencecriteriaismet,ortheoptimizationprocesshasreachedamaximumnumberofiterations.SimulationResults:WeevaluatedtheeffectivenessoftheproposedparametertuningalgorithmviasimulationsusingtheMatlabsoftwarepackage.Thenetworkisassumedtoconsistofasinglesourcenodeandmultipledestinationnodes.ThesourcenodesendspacketstothedestinationnodesusingnetworkcodingschemesbasedontheBBdistributionchannel.ThesimulationparametersaresummarizedinTable1.Table1:SimulationParametersParameterValueNumberofDestinationNodes5PacketSize500BytesChannelModelBBDistributionEncodingCoefficients4DecodingCoefficients2Wecomparedtheperformanceoftheproposedparametertuningalgorithmwithtwoothermethods:arandomselectionofparametersandafixedsetofparameters.Figure1showsthenetworkcodingthroughputanddecodingdelayofthethreemethods.Figure1:NetworkCodingThroughputandDecodingDelayAsshowninFigure1,theproposedparametertuningalgorithmachievesahighernetworkcodingthroughputandalowerdecodingdelaythantheothertwomethods.ThisresultconfirmstheeffectivenessoftheproposedparametertuningalgorithmfornetworkcodingschemesonaBBdistributionchannel.Conclusion:Inthispaper,wehaveproposedaparametertuningalgorithmfornetworkcodingschemesoperatingonBBdistributionchannels.Thealgorithmmaximizesthenetworkcodingthroughputandminimizesthedecodingdelaybyadjustingthevaluesoftheencodinganddecodingcoefficientsandthemessag