NTL Record

Title Alternate Waveforms for a Low-Cost Civil Global Positioning System Receiver
Record ID 42101
Personal Name
Creator
Vandevenne, Herman F.; Kelly, Edward J.
Source 128p. in various pagings
Corporate Creator Massachusetts Institute of Technology; John A. Volpe National Transportation Systems Center (U.S.)
Publisher United States. Department of Transportation. Federal Aviation Administration
Publication Date 19800601
Language English
Abstract This report examines the technical feasibility of alternate waveforms to perform the GPS functions and to result in less complex receivers than is possible with the GPS C/A waveform. The approach taken to accomplish this objective is (a) to identify, after a quick broad overview, a few promising waveforms, (b) to complete the architectural synthesis of a GPS system based on the new waveforms, (c) to analyze the performance of these systems in providing ranging and communication capability and (d) to assess the impact on receiver hardware and software. One conclusion is that the class of pulsed waveform, when combined with emerging matched filter technology, permits the use of a greatly simplified receiver design. A major part of the report consists of description of a pulse-based GPS design. Although very specific, the design was intended as a vehicle for performance analysis only and many refinements and alternatives within the same class are possible. Other classes of waveforms such as tone ranging and chirped FM waveforms, although adequate, do not seem superior to the present PN encoded CW waveform for GPS. Finally, if the 'alternate' waveform is simply the present C/A waveform but with a substantially increased power level, it is shown that with the present designs the performance will be greatly increased or, alternatively, performance margin can be traded for a simplified receiver implementation.
Public Note Introduction, Review of waveform choices, Use of present C/A waveform with more power, A TDMA pulsed GPS waveform, A TDMA tone ranging GPS waveform, PRFDMA waveform, Implications of the TDMA format, Appendices
Rosap ID dot:9356
Rosap URL https://rosap.ntl.bts.gov/view/dot/9356
TRT Terms Global Positioning System; Navigation devices; Waveform analysis; Civil aviation
General Subjects Global positioning system; Navigation receiver; Ranging waveforms; Tone ranging; Clock stability; CCD matched filter application; Charged coupled devices; Chirp filters; Civil aviation; Peak power
Classification NTL - AVIATION - Air Traffic Control
Geographical
Coverage
United States
OCLC 6498044
Contract Number DOT/TSC-RA-78-06
Report Number DOT-TSC-FAA-79-24; FAA-EM-79-16
Availability Volpe National Transportation Systems Center, Technical Reference Center
Resource type Tech Report
URL https://ntlrepository.blob.core.windows.net/lib/42000/42100/42101/DOT-TSC-FAA-79-24.pdf
Format PDF
Database NTL Digital Repository