Smart Antenna Research

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Smart Antenna Research Under

the GloMo Program

Smart Antenna Research Under

the GloMo Program

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The ProblemThe Problem

BaseStation

Uplink

Multipath

Uplink

Mobile

Downlink   Multipath

Intercell

Interference

Signal Fading

Limitations on Capacity

•Co-channel interference

•Multiple access interference

•Adjacent channel interference

•Multipath, fading, and noise

Apparent Solution

DSP Interference Rejection Techniques

Reality of the Solution

•High power consumption

•Excessive computing needed

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Research AreasResearch Areas

l Adaptive Antenna and Direction

Finding Algorithms and Hardwarel Hand-Held Smart Antennas

l Vector Channel Modeling

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Adaptive Antenna and

Direction FindingAlgorithms and Hardware

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Code Timing

Spatial Filters

Despreaders

Demodulator 

and

Beamforming

Algorithm

Front End for Antenna 1ADC / DDC

(SigTek ST-114)BPF

IF

AMP

Local Oscillator 

X IF LPF

~f=1982 MHZ

f=2050 MHZ

Front End for Antenna 8ADC / DDC

(SigTek ST-114)BPF

IF

AMP

Local Oscillator 

X IF LPF

~f=1982 MHZ

f=2050 MHZ

ApplicationsDemonstrateinterference

rejection through

spatial filtering

Study algorithm

performance

Perform AoA estimation forposition location applications

Developing spatialchannel models

Third Generation Array

DSPTI C549/C541

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Multi-Target CMAMulti-Target CMA

CMA

+

CMA

+RF Front End

&

Baseband conversion

RF Front End

&Baseband conversion

RF Front End

&

Baseband conversion

Gram-Schmidt

Orthogonalizer 

User 1 output

User M output

1

2

M

Port # 1

Port # M

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Accomplishments

l Smart Antennas at the HandsetÕCreated and built 2 measurement systems to measure

 propagation characteristics as seen by the handset

ÕInitial data collection shows an improvement of up to

17 dB in the link budget with adaptive combining and

7dB with diversity combining

Antenna Unit

VectorChannelMeasurementSystem

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MPRG Vector Measurement SystemMPRG Vector Measurement System

l

  Fully functional 8 elements,1.25 MHz Bandwidth, 2.050GHz center frequency

l  Flexible for adapting variousantenna/polarization inputs,carrier frequencies,bandwidths, real-time

algorithms, or data collectionscenarios

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

21010

l  New features being addedÕ  CDMA capabilityÕ  Improved systemexecutive processing

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Research IssuesResearch Issues

l Adaptive array algorithm performance

in real situations

l Vector channel measurementsl Practical AOA algorithm and

hardware development

l Adaptive array algorithm convergenceissues

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Future Work - Summer 98 ResearchFuture Work - Summer 98 Research

MPRG's vector 

measurement system will

 be located at a point along

the Smart Road and will

estimate the angle at whichthe signal arrives at the

array. This angle defines

the line of bearing.

Channel measurements will

also be made to quantify

the impact of the channel

on measurement accuracy.