smart antenna research under the glomo programsss-mag.com/pdf/mprg9.pdf · 1998. 12. 8. · l...

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Smart Antenna Research Under the GloMo Program Smart Antenna Research Under the GloMo Program

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  • Smart Antenna Research Underthe GloMo Program

    Smart Antenna Research Underthe GloMo Program

  • 45

    The ProblemThe Problem

    BaseStation

    Uplink

    Multipath

    Uplink

    Mobile

    Downlink Multipath

    IntercellInterference

    Signal Fading

    Limitations on Capacity•Co-channel interference•Multiple access interference•Adjacent channel interference•Multipath, fading, and noise

    Apparent SolutionDSP Interference Rejection Techniques

    Reality of the Solution•High power consumption•Excessive computing needed

  • 46

    Research AreasResearch Areas

    l Adaptive Antenna and DirectionFinding Algorithms and Hardware

    l Hand-Held Smart Antennasl Vector Channel Modeling

  • 47

    Adaptive Antenna andDirection Finding

    Algorithms and Hardware

  • 48

    Code Timing

    Spatial Filters

    DespreadersDemodulator

    andBeamforming

    Algorithm

    Front End for Antenna 1ADC / DDC

    (SigTek ST-114)BPFIF

    AMP

    Local Oscillator

    X IF LPF

    ~f=1982 MHZ

    f=2050 MHZ

    Front End for Antenna 8ADC / DDC

    (SigTek ST-114)BPFIF

    AMP

    Local Oscillator

    X IF LPF

    ~f=1982 MHZ

    f=2050 MHZ

    ApplicationsDemonstrateinterference

    rejection throughspatial filtering

    Study algorithmperformance

    Perform AoA estimation forposition location applications

    Developing spatialchannel models

    Third Generation Array

    DSPTI C549/C541

  • 49

    Multi-Target CMAMulti-Target CMA

    CMA

    +

    CMA

    +RF Front End

    &Baseband conversion

    RF Front End&

    Baseband conversion

    RF Front End&

    Baseband conversion

    Gram-SchmidtOrthogonalizer

    User 1 output

    User M output

    1

    2

    M

    Port # 1

    Port # M

  • 50

    Accomplishmentsl Smart Antennas at the HandsetÕ Created and built 2 measurement systems to measure

    propagation characteristics as seen by the handsetÕ Initial data collection shows an improvement of up to

    17 dB in the link budget with adaptive combining and7dB with diversity combining

    Antenna Unit

    VectorChannelMeasurementSystem

  • 51

    MPRG Vector Measurement SystemMPRG Vector Measurement Systeml Fully functional 8 elements,1.25 MHz Bandwidth, 2.050GHz center frequency

    l Flexible for adapting variousantenna/polarization inputs,carrier frequencies,bandwidths, real-timealgorithms, or data collectionscenarios

    l Eight Harris 40214Programmable Direct DigitalDownconverters, eight C54xDSPs, one Analog Devices21010

    l New features being addedÕ CDMA capabilityÕ Improved systemexecutive processing

  • 52

    Research IssuesResearch Issues

    l Adaptive array algorithm performancein real situations

    l Vector channel measurementsl Practical AOA algorithm and

    hardware developmentl Adaptive array algorithm convergence

    issues

  • 53

    Future Work - Summer 98 ResearchFuture Work - Summer 98 Research

    MPRG's vectormeasurement system willbe located at a point alongthe Smart Road and willestimate the angle at whichthe signal arrives at thearray. This angle definesthe line of bearing.Channel measurements willalso be made to quantifythe impact of the channelon measurement accuracy.