Course 452:
Navigation Receiver Signal Processing:
Advanced Baseband Processing for High Performance GPS Receivers

Courses included in 452:
Course 452A: (first 3.5 Days)
Advanced Baseband Processing for High Performance GPS Receivers

Course 452B: (last 1.5 Days)
GPS & Galileo New Signals, Signal Processing & Performance Capabilities

Please contact Carolyn McDonald at cmcdonald@navtechgps.com for more information.

Instructors

Mr. Phillip Ward, Navward GPS Consulting
Mr. Logan Scott, LS Consulting

Objectives

• To provide technical professionals with an in-depth understanding of GPS signal structures, receiver signal processing techniques, receiver system tradeoffs and how the processing techniques perform in a variety of environments. These include outdoor and indoor regions that are jamming, spoofing & multipath impaired.

• To provide a practical approach to receiver design and analysis from a conceptual perspective. This course focuses on advanced baseband acquisition, tracking and signal processing fro high performance receivers.

Prerequisites

• Electrical Engineering degree or equivalent experience required.

• Course 356 or equivalent professional experience recommended. 

• Understanding of basic GPS operation, signal structure and signal processing techniques is desirable.

Who Should Attend?

• Engineers, system analysts and others who require in-depth knowledge of GPS receiver technology for the purpose of building, modifying, or designing receivers.

• User equipment (UE) designers and integrators.

Course Schedule

COURSE 452A:  
ADVANCED BASEBAND PROCESSING FOR HIGH PERFORMANCE GPS RECEIVERS

8:30 - GPS Signal Characteristics
Satellite signal modulation
Frequencies and modulation format
GPS satellite signal structure
GPS signal structure for L1
GPS code mixing with data
GPS L1 carrier modulation

9:45 - Satellite Code Generators
Direct sequence PRN code generation
Code phase assignments and initial code sequences for C/A and P-code
C/A code generator
P-code generator
GPS code generator polynomials and initial states

11:00 - Satellite Signal Power & Antenna Array
Satellite signal power levels; minimum received GPS signal power levels
L1 and L2 navigation satellite signal power budgets
GPS satellite helix array gain pattern
Satellite to user geometry and path loss equations
Satellite signal power budget
GPS satellite antenna relative power patterns

12:00 - Lunch on your own

1:30 - Autocorrelation Functions and Power Spectral Densities
GPS signal power spectrum
Autocorrelation function, spectrum, and power ratios for a typical C/A-code
Normalized and simplified autocorrelation function typical C/A ad P(Y)-codes 
Comparisons between C/A-code and P(Y)-code autocorrelation
Power spectrum of L1 P(Y)-codes and C/A-codes from a GPS signal generator
L2 P(Y)-codes and L1 C/A-codes from a GPS signal generator showing line spectra
Cross-correlator functions & code division multiple access performance
C/A maximum cross-correlation power

4:00 - Receiver Noise 
Carrier to noise power ratio - C/N0 
Generalized model of a GPS receiver-computing G/T
G/T model equation formulation
Deriving C/N0 from G/T model equation
C/N0 versus received signal level

GPS Satellite Signal Tracking
Receiver code and carrier tracking
Generic digital receiver block & channel diagram
Generic baseband processor code and carrier tracking loops block diagram
Predetection integration

5:00 - Day 1 ends

8:30 - Baseband Signal Processing
Phase alignment; predetection integrate/dump intervals with SV data transition boundaries 
Carrier aiding of code loop 
Scale factors for carrier aided code 
External aiding
Digital frequency synthesizer block diagram, output waveforms, and synthesizer design

9:45 - Carrier Tracking Loops
Carrier tracking loops
Generic GPS receiver carrier tracking loop block diagram
Phase lock loops
Common phase lock loop discriminators
Costas loops, and common discriminators
Comparison of Costas PLL discriminators
I, Q phasor diagram depicting true phase error between replica and incoming carrier phase

11:00 - Frequency Lock Loops (FLL's)
Frequency lock loop discriminators; compare I, Q phasor diagram; true frequency error

Code Tracking Loops
Generic GPS receiver code tracking loop
Common delay lock loop discriminators 
Comparison of delay lock loop discriminators 
Code correlation process for 3 code phases; 1/2 chip early, etc.
Code discriminator output versus replica code offset

12:00 - Lunch on your own

1:30 - Receiver Tracking Loops I
Loop filter 
Block diagrams of first, second, and third order analog loop filters 
Loop filter characteristics 
Block diagram of analog, digital boxcar and digital bilinear transform integrators
Block diagrams of 2 FLL-assisted PLL filters
Loop filter parameter design example

2:45 - Measurement Errors and Tracking Thresholds I
PLL tracking loop measurement errors
PLL thermal noise
PLL thermal noise jitter plot
Vibration-induced oscillator phase noise

4:00 - Measurement Errors and Tracking Thresholds II
Allan deviation oscillator phase noise
Allan deviation jitter in L1 second order PLL
Dynamic stress error
Reference oscillator acceleration stress error

5:00 - Day 2 ends

8:30 - Measurement Errors and Tracking Thresholds III
Total PLL tracking loop measurement error and thresholds
Total PLL jitter for third-order carrier loop plot
Jerk stress thresholds for third-order PLL
FLL tracking loop measurement errors

9:45 - Measurement Errors and Tracking Thresholds IV
FLL thermal noise jitter plot
Jerk stress thresholds for second order FLL
Code tracking loop measurement errors
DLL jitter plots

11:00 - Tightly-coupled and Vector (Ultra-tightly Couled) Tracking Loops
Synergism between GPS and various GPS/inertial architectures
Inertial systems leading to tightly-coupled configurations
Issues in a tightly-coupled configuration
Vector tracking (ultra-tightly coupled) loop configurations
Ultra-tightly coupled vs. tightly-coupled configuration

12:00 - Lunch on your own

1:30 - Formation of Pseudorange, Delta Pseudorange and Integrated Doppler I
Pseudorange definition and measurement 
Relationship of satellite transmit time to pseudorange measurements 
Relationship between PRN code generator and code accumulator 
Measurement time skew 
Maintaining and getting measurement from the code accumulator 
Synchronizing the code accumulator to the C/A-code and P-code

2:45 - Formation of Pseudorange, Delta Pseudorange and Integrated Doppler II
Code setter and code generator block diagram 
C/A-code and P-code setup 
Count states for 3,749th and 3,750th cycles of X1A in first X1 cycle of week 
PN code states corresponding to final two and reset count states 
Count states for 3,749th and 3,750th cycles of X1A in last X1 cycle of week

4:00 - Formation of Pseudorange, Delta Pseudorange and Integrated Doppler III
Flowchart of P-code setter algorithm
Obtaining transmit time from the C/A-code 
GPS C/A-code timing relations 
Example of bit sync error in C/A-code measurements
Delta PRN & integrated Doppler measurements
Workshop

5:00 - Day 3 ends

8:30 - Signal Acquisition I
2D C/A-code search pattern 
Probability density functions for a binary decision; probability of false alarm, false dismissal, detection and correct dismissal 
The Generalized Marcum's Q-function 
Taxonomy of search detectors 
Example of fixed dwell time detector: M of N search detector

9:45 - Signal Acquisition II
Probability of detection for M of N search algorithm 
Example of variable dwell time detector: Tong search detector 
Tong sequential code search algorithm flow chart 
Probability of detection for Tong search algorithm

11:00 - Misc. Important Baseband Functions
Bit & symbol synchronization
Reading the current signal's 50 bps data stream
Interleaving and convolutional encoding; reading future signal's data 
C/N0 meter design & performance
Phaselock detector design 

12:00 - Lunch on your own

COURSE 452B:  
GPS & GALILEO NEW SIGNALS, SIGNAL PROCESSING & PERFORMANCE CAPABILITIES

1:30 - GPS & Galileo New Signals Overview
Frequency allocations & spectral characteristics
Deployment schedules and resulting capabilities
The European Galileo Program

2:45 - Basics of BOC Modulation & Tracking (Part 1)
BOC signal structure and generation
M-code characteristics and design criteria
Galileo signal characteristics

4:00 - Basics of BOC Modulation & Tracking (Part 2)
BOC tracking loop design
False code lock detection & correction
Pseudorange tracking accuracy

5:00 - Day 4 ends

8:30 - L2 and L5 Civil Signal Structures
Signal structures and specifications
Tracking Loop Design & Performance
Use of the "data free" channel to enhance threshold performance

9:45 - Multipath Mitigation Techniques
Why multipath is becoming a more important error source
Narrow spacing correlator
Strobe correlator
Early gate tracking

11:00 - Anti-Jam Capabilities of the P(Y), C/A & M-code Signals (Part 1)
The Betz equation for computing baseband C/N0
Processing gain for BOC signals
Comparative performance against a variety of jammer types
Split spectrum tracking & acquisition 

12:00 - Lunch on your own

1:30 - Anti-Jam Capabilities of the P(Y), C/A & M-code Signals (Part 2)
Spot beam (area coverage) plans and implications
Basics of ground mobile signal propagation
Predicting received jamming strength
Anti-jamming performance for the ground mobile user
Prospects for civil signal denial

2:45 - Advanced Signal Acquisition
FFT & massive correlator approaches
Direct P(Y) acquisition and M-code assisted acquisition
Operation in indoor/impaired signal environments

4:00 - Miscellaneous Topics
Combined GPS/Galileo performance
Interplex modulation; keeping the signal constellation circular
Summary of principal elements of course
Question & answer session
Comments and conclusion

5:00 - Course ends

Materials You Will Keep

• A notebook including all materials presented in course

• NavtechGPS CD-ROM containing a variety of GPS references.

Continuing Education Units

Attendee Quotes

“Thanks much. Your course offerings have proven to be extremely useful from a technical (as well as networking) perspective. Phil is an excellent resource.” 
- Pete Ryan, Honeywell

“Phil Ward is a very knowledgeable instructor who explains things very clearly. I recommend this course for anyone needing an introduction to GPS receiver design.”
- Ernest Ohlmeyer, NSWC

“This course will help me understand and solve many GPS receiver problems. It gave me the knowledge I needed about the operability of GPS; way beyond the everyday GPS knowledge that a typical user has obtained. It gets the student into the nuts and bolts of the system.”
- Michael Bailey, NAWC-WD China Lake

“This course will help in analyzing problems brought to CIGTIF concerning GPS anomalies.” 
- Jim Killian, AMCOMP

“This course has given me, in detail, a fundamental understanding of the building blocks required for GPS signal processing.  This course will help me better understand the design decisions faced in building a GPS receiver.” 
- George Kalaydjian, Canadian Marconi Company

“I am moving into the area of receiver processing and this course has given me a good understanding of the signal processing aspects.” 
- Kevin J. Neigum, Rockwell Collins

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