Modeling a Multicarrier Wireless Communication TransceiverOverviewMulticarrier ModulationMotivation for Multicarrier ModulationExisting Work and ResearchPowerPoint PresentationProject GoalsQUESTIONS?Modeling a Multicarrier Modeling a Multicarrier Wireless Communication Wireless Communication TransceiverTransceiverEmbedded Software SystemsEmbedded Software SystemsLiterature SurveyLiterature SurveyMarch 24,2004March 24,2004By Hunaid LotiaOverviewOverview•Multicarrier ModulationMulticarrier Modulation•MotivationMotivation•Existing ResearchExisting Research•OFDM (Orthogonal Frequency OFDM (Orthogonal Frequency Division Multiplexing)Division Multiplexing)•GoalsGoals•QuestionsQuestionsMulticarrier ModulationMulticarrier Modulation•Technique in which multiple frequencies Technique in which multiple frequencies are used to transmit dataare used to transmit data•Divide broadband channel into Divide broadband channel into narrowband sub channelsnarrowband sub channels•Widely used in ADSL and wireless LANWidely used in ADSL and wireless LANMotivation for Multicarrier Motivation for Multicarrier ModulationModulation•Applications requiring high rate data Applications requiring high rate data transmission.transmission.•Increasing power of Digital Signal Increasing power of Digital Signal Processing tools. (1960’s)Processing tools. (1960’s)•Applications range from Digital Audio Applications range from Digital Audio and Video Broadcasting to High-and Video Broadcasting to High-Speed Wireless LANs.Speed Wireless LANs.Existing Work and ResearchExisting Work and Research•Most common candidates for Multicarrier Most common candidates for Multicarrier Wireless (Mobile) Communication are:Wireless (Mobile) Communication are:•Direct Sequence Code Division Multiple Direct Sequence Code Division Multiple Access (DS-CDMA)- Receiver Complexity Access (DS-CDMA)- Receiver Complexity •Frequency Hopping-CDMA (FH-CDMA)- Frequency Hopping-CDMA (FH-CDMA)- Requires powerful channel coding to Requires powerful channel coding to mitigate fading effects.mitigate fading effects.•Solution: OFDM Transmission SystemSolution: OFDM Transmission System–Considered for fourth-generation mobile Considered for fourth-generation mobile communication systems.communication systems.P/SQAM decoderinvert channel=frequencydomainequalizerS/Pquadrature amplitude modulation (QAM) encoderN-length Inverse FFTadd cyclic prefixP/SD/A +transmit filterN-length FFTS/Premove cyclic prefixTRANSMITTERRECEIVERN subchannels N complex samplesN complex samplesN subchannelsReceive filter+A/Dmultipath channelAn OFDM Modem An OFDM Modem BitsProject GoalsProject Goals•Model the OFDM system in Model the OFDM system in Synchronous Dataflow (SDF)Synchronous Dataflow (SDF)–All nodes produce and consume fixed All nodes produce and consume fixed number of tokensnumber of tokens–Use SDF domain in Ptolemy to verify the Use SDF domain in Ptolemy to verify the modelmodel–Investigate other open issues that come Investigate other open issues that come up as the projects builds upup as the projects builds
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