tom fisher – 3021495 supervisor - a/prof andrew dempster assessor - dr jinho choi combining gps...

Tom Fisher – 3021495

Supervisor - A/Prof Andrew Dempster

Assessor - Dr Jinho Choi

Combining GPS and CDMA Cellular Network Measurements for Positioning


Cellular Network Positioning

DefinitionEquipment and algorithms applied to CDMA cellular wireless telecommunications to determine geographic position, and in some cases the velocity and direction of travel of wireless devices.

Source: http://www.3gamericas.org/English/Technology_Center



Stakeholders

Emergency Services (esp. US)

Communications Authorities

Mobile Phone Operators – E911 (2000-2005)

Mobile Phone Users



Benefits

Enhanced 911 (FCC 2000 Mandate)

Traffic Information

Location Based Billing

Enhanced Roadside Assistance

RF/Network Optimisation

Navigational Assistance

Personal Location



Current Standards and Previous Work

IS-801 (Positioning Standard)

IS-95 (CDMA Communications Standard)

Rappaport (Various Papers)

SNAP Laboratory Work

UWCC Mobile Positioning Study

FCC 94-102 Phase II Automatic Location Identification


Positioning Concepts

Concept of Positioning

GPS: Uses at least 3 satellites (4th for time/DGPS)

Uses Trilateration to determine position

Uses timing signals to determine relative position

Source: http://www.dod.mil/gps.html



GPS

Each satellite sends 2 signals:

Location of Satellite:

Timing signal (Pseudo-Random Code):

For the Receiver:

Transmit time:

Distance from Satellite:

1 ( , , )s s sS x y z

2 sentS t

total recv sentt t t

satellite totald ct



GPS

satellited

Source: http://mail.colonial.net/~abeckwith/gps.html

The receiver is somewhere on a sphere of radius

Intersection of 3 spheres leaves possible 2 locations

Impossible locations are ignored

Coordinates are now known

( , , )e e ex y z

( , , ) ( , , )e e ex y z Lat Long Elev



Technology Approaches Network-Based Approaches

Time Difference of Arrival (TDOA)

Angle of Arrival

Multipath Analysis

Receive Power

Handset-Based Approaches GPS

Network-Assisted GPS

Advanced Forward Link Trilateration

Enhanced Observed Time Difference (E-OTD)

Source: Caffery and Stüber: Subscriber location in CDMA Cellular Networks, 1998



Compatibility

Network-Based Approaches Does not require air interface modifications

Requires additional base station equipment

Added system maintenance

Handset-Based Approaches Requires air interface modifications (TIA PN-4589 and TR 45.1)

Requires handset upgrades/replacement

Added system maintenance



UWCC Study Findings

Universal Wireless Communications Consortium (UWCC)

Revenue from New Services

Location is High Value, Low Bandwidth Data

Location Powers the Wireless Web

Enriches Value Added Internet Content



Proposed Solution

2 Goals:

Minimal Network Changes / Maximum Compatibility

Greatest Accuracy

2-D solution

Explore hybrid Handset/Network solutions

Conform to Australian and International Standards

Make recommendations for Australian E-000



Proposed Solution

Combination Network-Based Solution

TDOA

Receive Power

Hybrid Network/Handset Solution

E-OTD

Investigate Practicality and User Impact


Thesis A Current Status

Current Status

Literature Review Completed by Session 1

Binghao Li’s Test Data Collated and Processed

Thesis Part B Planned


Thesis B Planning

Timeline

Schedule has thus far been Accurate

Resources Acquired

GPS Reference Books

TDOA Test Data

Questions

tom fisher – 3021495 supervisor - a/prof andrew dempster assessor - dr jinho choi combining gps...

Documents

positioning slide

positioning standard

combining gps

cdma cellular networks

center slide

system maintenance slide

location of satellite

subscriber location