Requirements of a CCDMA Pseudolite Indoor Geolocation System - PowerPoint PPT Presentation

1 / 28

About This Presentation

Title:

Requirements of a CCDMA Pseudolite Indoor Geolocation System

Description:

Excellent (EX): ideal signal reception. ... Girlfriend. Sunni. Dallas. Mavericks. Dancer. Super Star. for taking. 99.999 % of my time ... – PowerPoint PPT presentation

Number of Views:113

Avg rating:3.0/5.0

Slides: 29

Provided by: ilirp

Category:

more less

Transcript and Presenter's Notes

Title: Requirements of a CCDMA Pseudolite Indoor Geolocation System

1
Requirements of a C-CDMA Pseudolite Indoor
Geolocation System

Ilir F. Progri, Giftet Inc., Pomona, CA
William R. Michalson, WPI, Worcester, MA
Jinling Wang, University of New South Wales,
Australia
Matthew C. Bromberg, Elected Engineering,
Leominster, MA
R. James Duckworth, WPI, Worcester, MA
Presented at
ION-AM 2007, April 23-25, 2007
Cambridge, MA

2
Overview

Introduction
General requirements of a C-CDMA indoor
geolocation system
System requirements
C-CDMA pseudolite requirements
C-CDMA receiver requirements
Simulation requirements
Summary conclusions

3
Introduction

A C-CDMA pseudolite geolocation system describes
a
a code division multiple access (CDMA)
a frequency division multiple access (FDMA)
a pseudolite indoor geolocation system
the proposed transmitter and receiver designs
a continuation of the work initially developed by
Progri and Michalson
some initial simulation results in the presence
of Rayleigh and Rician multipath fading, AWGN,
phase and frequency offsets.

4
Introduction Cont.

Work that we have been doing for the past 6
years.
Analysis
C-CDMA indoor geolocation system concept
C-CDMA pseudolite signal selection
characteristics
multipath parameters selection and modeling
receivers signal processing

5
Introduction Cont.

Simulation
MATLAB and Simulink simulations
A good deal of research on indoor geolocation
channel models and selection of parameters of
interests for path loss and multipath
distribution.
Implementation
C-CDMA pseudolite
C-CDMA receiver

6
Introduction Cont.

General requirements of a C-CDMA indoor
geolocation system
System requirements
C-CDMA pseudolite requirements
C-CDMA receiver requirements
Simulation requirements
General methodology
Giftet Inc. C-CDMA global solution product (not
included in this presentation)

7
General Requirements

The general requirements of a C-CDMA pseudolite
indoor geolocation system include
(a) system requirements
(b) pseudolite (or transmitter) requirements
(c) receiver requirements.

8
System Requirements

A C-CDMA pseudolite indoor geolocation system
must consist of at least 4 or more C-CDMA
pseudolites and one or more C-CDMA receivers.
Coverage area and transmitter receiver radius R.
The pseudolites located at the outside the
perimeter and at a reasonable height.
The system should have the ability to perform
distance measurement via time of arrival
measurement (TOA).

9
System Requirements Cont.

Under these conditions a C-CDMA pseudolite indoor
geolocation system should provide cm level 3-D
position accuracy and cm/sec level velocity
accuracy 99.999 of the time.
Portability and flexibility are desired in that
the system should have the ability to reconfigure
itself.

10
(No Transcript)
11
C-CDMA Pseudolite Requirements

A frequency allocation for signal separation of
at least 5 MHz/pseudolite.
It appears that radio frequency spectrum is now
on the orders of 100 million for MHz which could
implies that the frequency spectrum for a C-CDMA
pseudolite would be 0.5 billion and for 4
pseudolites would be 2 billions. This parameter
alone would make the system almost impossible to
build and commercialize it.

12
C-CDMA Pseudolite Requirements Cont.

Center of frequency spectrum of what is available
and what is affordable in the frequency spectrum
of 3.1 10 GHz as mandated by the FCC.
A pair of unique Kasami sequences for signal
spreading for the in-phase and quadrature
components.
VBOC(2,1,a) for signal spreading modulation to
further minimize multipath and interference
effects.

13
C-CDMA Pseudolite Requirements Cont.

QPSK modulation for combining the I and Q
channels and maintaining the time orthogonality
between the I and Q channels.
Size of the pseudolite should be as small as
possible using COTs.
Pseudolite should be powered up from a 120V/60
Hz outlet via a power supply via an AC/DC
converter.

14
C-CDMA Pseudolite Requirements Cont.

The pseudolite signal power should range from ?50
to ?100 dBm at distances from 10 m to 100 m from
the pseudolite in free space. In an actual indoor
environment signal degradation will be higher,
which could lead to actual pseudolite signal
levels at 100 m to be ?150 dBm.
Data rate of at least 1 kHz or higher.

15
C-CDMA Pseudolite Requirements Cont.

One of the pseudolites should be designated as
the master pseudolite and all the others are
designated as slave pseudolites. All the clock
parameters of the other pseudolites should be
referenced to the master pseudolite.
The user must be able to enter the pseudolite
location via a GPS receiver having surveying the
location of the pseudolite first.

16
(No Transcript)
17
Receiver Design Requirements

A single or multiple antennae. Multiple antennae
maybe desired if interference and jamming
protection is required.
At least 80 dB of receiver dynamic range is
required to enable signal acquisition and
tracking from all the pseudolites.
If possible the receiver should perform the
signal processing at the RF frequency via
software defined radio.

18
Receiver Design Requirements

The receiver should employ either a maximum
likelihood parameter estimation or Bayesian Monte
Carlo Markov Chain (MCMC) integration for joint
signal acquisition and tracking
De-spread
Demodulate Decode

19
Receiver Design Requirements Cont.

Perform distance measurement between the receiver
and all pseudolites.
Take into account the effect of transmitter clock
stability on position accuracy such effects will
include the transmitter and receiver oscillator
drift (short term stability) on positioning
accuracy.

20
Receiver Design Requirements Cont.

The signal processing on the receiver design
should include techniques for detecting an
extremely week LOS signal and for maintaining
lock on the LOS signal in the presence of severe
multipath, interference, and jamming.
Each receiver channel should have a status
indicating the quality of the signal from the
following list

21
Receiver Design Requirements Cont.

Excellent (EX) ideal signal reception. No signal
reflection or obstruction or 0 dB signal
degradation which means that power loss is only
due to transmitter receiver geometry i.e., free
space signal propagation.
Very good (VG) very good signal reception, minor
reflection or signal obstruction or ?10dB signal
degradation.

22
Receiver Design Requirements Cont.

Good (G) good signal reception, some reflection
and signal obstruction or ?20dB signal
degradation.
Average (AV) average signal reception due to
reflections and signal obstructions or ?30dB
signal degradation.
Poor (PO) poor signal reception due to
significant reflections and signal obstructions
or ?40dB signal degradation.

23
Receiver Design Requirements Cont.

Very poor (VP) very poor signal reception due to
extreme (or severe) signal reflections and signal
obstructions or ?50dB to ?80 dB signal
degradation.
Noise (NO) no signal is present or no useful
signal information is available.

24
Simulation Requirements

A C-CDMA pseudolite indoor geolocaiton system
must be fully and accurately simulated in MATLAB
and Simulink.
Simulink and MATLAB simulation must include
signal characteristics, C-CDMA pseudolite design,
C-CDMA receiver design, and channel
characteristics.

25
Simulation Requirements Cont.

Simulation must allow portability and flexibility
in that signal characteristics and channel
parameters can be changed and altered to allow
simulation of desired scenarios and be able to
test all the desired signal levels on the
software.
Examples of simulation requirements are provided
in previous publications which maybe reused and
improved to include the added requirements of a
C-CDMA pseudolite indoor geolocation system.

26
Methodology

The methodology that we will follow will be
illustrated further in Giftet Inc. software
products which will be presented at the ION GNSS
2007.
Giftet is a privately held company for
developing, marketing, and distributing global
navigation, software, and web solutions for
Indoor Geolocation Systems, GPS, GLONASS,
Galileo, QZSS, and other Global Satellite and/or
Pseudolite Navigation (or Positioning and/or
Timing) Systems based on customers needs.
Giftet philosophy is based on partnership!
Giftet welcomes partnership!
Giftet was founded in Pomona, CA on December 26,
2006.
http//www.giftet.com/

27
Summary and Conclusions

We have proposed the requirements of a 3-D C-CDMA
pseudolite indoor geolocation system as a
possible candidate for indoor geolocation.
Our requirements included
System requirements
C-CDMA pseudolite requirements
C-CDMA receiver requirements
Simulation requirements
General methodology
Giftet Inc. C-CDMA global solution product (not
included in this presentation)

28
Future Work