COURSE # TRO-359
GLOBAL NAVIGATION SATELLITE SYSTEMS (GNSS) :
— SPREAD SPECTRUM TECHNOLOGY
...a most comprehensive review of Spread Spectrum Technology for GNSS, including the operating principles, waveforms, systems and applications...
The rapid transition to Satellite-based Global Navigation, an initially restricted technology turned ubiquitous today, serves many vital needs. This course, presented by the author of the course textbook, provides sound engineering foundations of Global Navigation Satellite Systems (GNSS) which utilize Spread Spectrum (SS) technology. A brief history of GPS is presented, along with an in-depth coverage of SS techniques and the critically important synchronization of the codes and carrier, and includes the effects of systemic/propagation performance degradation, laying a solid ground for future pursuits in GNSS systems.
Applications and benefits:
You will benefit by enhancing your understanding of the :
- GPS and GNSS history and evolution.
- Language, terminology and metrics used in the GNSS community.
- Transmitter combining techniques, combining losses and objectives.
- Spread Spectrum concepts, techniques.
- Complete link assessment and the handling of interference due to other navigational signals and jamming.
- Ranging performance in GNSS systems.
Who should attend:
This course expands the understanding of the GNSS mission and performance, along with the intricate underlying SS technology and its critical parameters, such as code acquisition, code tracking, carrier tracking, and data demodulation, rendering it invaluable for industry executives, program managers, system analysts, simulators, engineers and others who manage, design or operate GNSS and/or develop applications that utilize GNSS.
Although this course has no prerequisites, for maximum benefit college level math and some familiarity with random processes will be beneficial.
Course Outline:
- GPS and GNSS history and evolution
- A brief history of spread spectrum systems
- Brief history of GPS and the other GNSS systems
- Concept of satellite navigation
- GPS, GFS IIF, GPS IIM, GPS III
- Other GNSS
- A brief introduction to processes and operations in GNSS
- A brief introduction to narrow band process via the complex envelope
- A brief summary of Gaussian random processes
- The matched filter
- The GNSS satellite transmitter combining process
- The Interplex modulation scheme
- Majority voting (MV) modulation
- Intervote which combines Interplex and MV
- Direct sequence spread spectrum systems (DSSSS)
- DS spread spectrum BPSK transmitter and receiver
- NRZ and Binary Offset Carrier (BOC) PN code symbol formatting
- Power spectral density of DS BPSK systems
- Some important performance measures in DSSS BPSK signaling
- Processing Gain for DSSS
- Correlation loss of a filtered DSSS BPSK signal
- Noise Spectral Density Reduction for DSSS BPSK despreading
- Interference in a GNSS receiver
- Near far problem
- Binary shift register code sequences for spread spectrum
- The need for shift register codes for DSSS using BPSK
- Finite field arithmetic and polynomial arithmetic
- An example of shift register sequence
- The autocorrelation function and the cross correlation of sequences
- Spectral Separation coefficient for dealing with inter and intra GNSS interference
- Codes used in practice
- Binary Maximal length codes and their spectral density
- Gold Codes and balanced Gold codes
- Computer generated codes
- DSSS BPSK System performance in presence of Jamming
- Wideband, partial band, pulsed, tone and matched spectral jammers
- Bit error rate performance for DSSS BPSK in wideband jamming
- Bit error rate performance for DSSS BPSK in partial band jamming
- Bit error rate performance for DSSS BPSK in pulsed jamming
- Bit error rate performance for DSSS BPSK in tone jamming
- Spectral separation and its use in assessing inter and intra GNSS interference
- Performance of DSSS in coded BPSK systems
- Interleavers used in coded systems
- Coding needs more bandwidth, but yields better bit error rates
- Worst case partial band jamming with a (7,4) block code BER
- Convolutional coding and its BER performance in WGN
- Parallel and serial concatenated codes, and low-density parity check codes
- An example of a serial concatenated code
- Carrier tracking for CW and BPSK data modulation
- The need for either a PLL or a Costas loop in DSSS
- The Phase Locked Loop (PLL)
- The phase locked loop tracking error performance in WGN
- The Costas loop
- Tracking performance of the Costas loop
- Information contained in GNSS data
- Mean time to lose lock
- Code acquisition in DSSS BPSK receivers
- The receiver for code acquisition and tracking, and data demodulation
- Types of code acquisition systems: RASE, Sequential detection Parallel active searching
- Passive matched filter
- Transform methods
- Code acquisition I: Parallel active code searching utilizing the FFT
- A single active search method and its mean code acquisition time
- Parallel correlator model
- The FFT searches frequency in parallel
- Expressions for the detection and false alarm probabilities
- Losses between bins in a padded FFT
- Mean acquisition time for a DSSS BPSK parallel active code search
- Code acquisition II: Sequential detection
- System diagram for Sequential detector
- Practical version of the sequential detector
- An output of a sequential detector when the signal is present and absent
- Acquisition time formula
- Code acquisition III: Digital passive matched filter (DPMF)
- Model of the DPMF
- Signal model of the DPMF
- FFT main lobe response with and without zero padding
- Direct sequence code tracking
- Baseband Coherent Early-Late Code tracking loop
- Tracking curves (S-Curves)
- Code loop tracking error performance
- Non Coherent Early-Late Code tracking loop
- Tracking curves
- Code loop tracking error performance
- Noncoherent I-Q Dot Product code tracking loop
- Tracking curves
- Code loop tracking error performance
- Multipath effects on noncoherent code tracking loops
- Multipath plots for δ = 0.5 and δ = 0.05 when unfiltered
- Multipath plots for δ = 0.5 when filtered
- Phase rotators in I-Q systems
- Lock detectors
- The need for lock detectors
- Phase locked loop lock detector model
- Costas loop lock detector
- An example of a "three consecutive counts" lock detector
- Low probability of detection systems (LPI)
- An introduction to LPI systems
- Scenario
- Types of LPI detectors
- Baseband and carrier cyclostationarity
- The "deflection" and its use in detection
- Radiometers
- Radiometer model
- PD and PFA for the radiometer
- Correlation radiometer
- Correlation radiometer model
- PFA and PD for the correlation radiometer
- Future Trends and GNSS evolution
- Improved accuracy
- More GNSS systems available
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- Receivers able to track more than one GNSS system
- Applications
Text: Spread Spectrum Systems for GNSS and Wireless Communications, by Jack K. Holmes, Artech House Publishers, 2007.
About the Instructor
Jack K. Holmes has been involved with nearly all stages of design, analysis and operation of Global Navigation Satellite Systems, since their inception. Over the years, he has worked at leading GNSS companies, including Hughes Aircraft, RCA Data Systems, The Jet Propulsion Laboratories, and TRW, contributing to GPS, GPS II, GPS IIA, GPS IIR-M, GPS IIF and also to GPS III, including the source selection process. His extensive experience spans Spread Spectrum systems including MILSTAR and some classified systems. He served on a number of modernization teams for GPS signals, including L1C, L2C, L5, and the new military M-code. Dr. Holmes has taught spread spectrum communications courses at UCLA extension, and at California State Northridge. In addition he has taught numerous short courses on the same subject. Dr. Holmes is a senior member of IEEE and has published approximately 50 papers and two text books. Dr. Holmes received his BS, MS and PhD from the UCLA School of Engineering.
Details:
Course: TRO-359 Duration: 3 Days FEE: $1,499 CEUs: 2.16
Please direct any additional inquiries regarding our courses to Zygmond Turski, Program Director, by e-mail, FAX: (240) 371-4488 or TELEPHONE: (202) 241-6326.
Call toll free 1-800-683-7267 from anywhere in the Continental U.S. or CANADA.
Last modified November 11, 2011
