Microwave Propagation Characteristics

8/13/2019 Microwave Propagation Characteristics

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Confiden t ial ProprietaryDoCoMo/Motoro la Meeting Ju ne 8 & 9, 2000

Microwave Propagation

CharacteristicsIn The MMDS Frequency Band

Jeffrey W. Porter and John A. Thweatt

Motorola Labs Communication Systems and Technologies

To be presented at the International Conference on Communications (ICC2000), June 18-22, 2000.


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Outline of Presentation

Introduction

Measurement Methods

Path Loss Results

Delay Spread Results

Conclusions


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Introduction

Study Objectives To determine path loss characteristics

To determine delay spread characteristics

System Parameters

Frequency Band - MMDS - 2.45 - 2.50 GHz

Transmitter:

43 meters high

53 sectored antenna, 11 dBi gain

Receiver:

5.2 - 16.5 meters 10 beamwidth directional antenna, ~21 dBi gain

Omni-directional antenna, 9 dBi gain


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Propagation Measurement System

Transmitter Site

IL02 Sector HQ, East

Penthouse

30 foot tower with rotator

Equipment cabinet

cabling, equipment rack,

workstation

propagationtestsignal

controllink

Test Truck with Mast

Transmitter

Equipment

Cabinet

Wireless control channel

Receiver Site

Motorola Labs Field Test

Vehicle Pneumatic mast, pan & tilt

Antenna assembly and camera

Workstation


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Measurement Campaign

Data collected at sites inSchaumburg, Hoffman

Estates, Palatine, etc.

Sites chosen for

representative coverage

Controlled by operator inthe test truck

Automated process with

LabView application

Measurement Data

1458 power measurements at 243 sites

58,300 power delay profiles recorded at 104 sites


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Path Loss Measurements

Transmit an unmodulated carrier at 2.496 GHz

using a vertical-polarized directional antenna

Receiver used a Spectrum Analyzer to determine

average power for 10 seconds

for vertical-polarized directional and omni-directional

antennas

at three antenna heights - 16.5 m, 10.4 m, 5.2 m (54,34, 17 feet)


7/16Confiden t ial ProprietaryDoCoMo/Motoro la Meeting Ju ne 8 & 9, 2000

* Varying the Antenna Height does not significantly affect path loss

LOS Path Loss - Directional Receive Antenna



* Varying the Antenna Height does not significantly affect path loss

LOS Path Loss - Omni-directional Antenna



NLOS Path Loss - Directional Antenna



NLOS Path Loss - Omni-directional Antenna



Summary of Path Loss Results

n = Path Loss Exponent

s= Standard deviation of n

N = Number of samples

Receive Antenna Height

16.5 meters 10.4 meters 5.2 meters

Visibility Receive Antenna

Type

n s N n s N n s N

LOS Directional 2.4 3.8 107 2.9 4.7 70 1.7 3.1 28

Omni-directional 2.4 3.4 90 2.6 4.6 66 2.1 3.5 27

NLOS Directional 2.1 10.5 132 2.9 11.4 143 4.1 12.6 168

Omni-directional 2.7 9.4 122 3.3 10.1 134 4.2 10.5 163



Objective: To measure the RMS Delay Spread and

determine the effects of LOS/NLOS conditions

determine the effects of antenna directivity

determine the effects of antenna height

Delay Spread Measurement System

SigTek 515 Channel Sounder

Parameters

20 Mcps Direct sequence spread spectrum (DS-SS)

Frequency at 2.475 GHz

Multipath Resolution of ~50 ns

30 dB processing gain

Delay Spread Measurements



Delay Spread for LOS and NLOS Conditions

50

60

70

80

90

100

0.0 1.0 2.0 3.0 4.0 5.0

RMS Delay Spread for LOS

RMS Delay Spread (s)

Directional

Omni-directional

%P

ro

babilityofRMSDelaySpr

ead

Microwave Propagation Characteristics

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