EP0501829A1
Expired / Lapsed
EP
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System and method for a digital navigation satellite receiver
Assignee: Texas Instruments Inc
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Filing: 1992-02-28
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Granted: —
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Expires: 2012-02-28
Abstract
Abstract There is disclosed a global positioning system receiver method and system which converts the analog signals to digital signals prior to performinng signal acquisition and GPS unique processing functions. The A/D converter (201) uses full null zone processing to increase anti-jamming capability and 4-level output to reduce signal processing. A. single analog and digital channel (302) is used for both the L1 and L2 channels as well as for all P(Y)-code and C/A-code thus allowing full multi channel tracking with several channels (202, 203, 204) each tracking a separate signal while the remainder of the channels rove over all of the signals on the alternate L-band with programmable duty cycles. The system allows for Y-code substitution for P-code by multiplexing a portion of the Y-code generated between multiple channels.
Inventors
- 👤 John P. Volpi
- 👤 Chyi H. Lu
- 👤 Mitchel B. Stiles
- 👤 Leonard J. Lapadula, Iii
- 👤 Hugh L. Scott
- 👤 George W. Pawlowski
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 14:05
CPC Classifications
G; G01; G01S; G01S19/00; G01S19/01; G01S19/13; G01S19/32; G01S19/21; G01S19/24; G01S19/35; G01S19/37
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
99 words
A receiver for determining a global positioning parameter from analog signal information received from a plurality of navigational satellites, said signal information having data shifts dependent upon distance and frequency shifts dependent upon the relative velocity between the satellite's transmission position and the geographical position of said receiver, and wherein said analog signal is significantly weaker than ambient atmospheric noise, said receiver comprising: a digital signal processing circuit for acquiring valid signals in the presence of said noise, for estimating the correct position and for correcting said estimate based upon data exchanged between said acquisition circuit and said processor.
Claim 2
Dependent Claim
150 words
A receiver for determining a global positioning parameter from analog signal information received from a plurality of navigational satellites, said signal information having data shifts dependent upon distance and frequency shifts dependent upon the relative velocity between the satellite's transmission position and the geographical position of said receiver, and wherein said analog signal is significantly weaker than ambient atmospheric noise, said receiver comprising: a first stage for accepting said analog signals from a plurality of said satellites and for modulating said received analog signals into equivalent IF analog signals; an analog to digital converter for converting said modulated IF signals into digital signals prior to further processing of said IF signals; a computer, and a digital signal processing circuit for acquiring valid signals in the presence of said noise, for estimating the correct position and for correcting said estimate based upon data exchanged between said tracking circuit and said computer.
Claim 3
Dependent Claim
16 words
The receiver set forth in claim 2 wherein said converter includes a full null zone detector.
Claim 4
Dependent Claim
28 words
The receiver set forth in claim 2 wherein said digital signal processing circuit includes a noise meter for aiding in said signal acquisition or aiding in signal tracking.
Claim 5
Dependent Claim
42 words
The receiver set forth in claim 2 wherein said analog satellite signal information is coded in P(Y)-code and in C/A code, and wherein said digital signal processing circuit includes: circuitry operable to track both said information codes simultaneously on a single channels.
Claim 6
Dependent Claim
33 words
The receiver set forth in claim 2 wherein said receiver includes an offbeat oscillator frequency which allows for digital oscillator to resolve carrier and P(Y)-code clock phase in order to process said P(Y)-code.
Claim 7
Dependent Claim
30 words
The receiver set forth in claim 5 wherein said digital signal processing circuit includes: a plurality of signal correlators for aiding in said signal acquisition of P(Y)-code and C/A code.
Claim 8
Dependent Claim
46 words
The receiver set forth in claim 1 further comprising: circuitry for tracking multiple channel is simultaneously, said circuitry including: circuitry for assigning a different signal to a plurality of said channels; and circuitry for time sharing a plurality of signals on the remainder of said channels.
Claim 9
Dependent Claim
58 words
The receiver set forth in claim 2 wherein said analog satellite signal information is coded in P(Y)-code and in C/A code and wherein said receiver further includes: circuitry for receipt of satellite data indicating status of anti-spoofing ; and circuitry operative in response to receipt of said status for converting said receiver from P-code operation to Y-code operation.
Claim 10
Dependent Claim
20 words
The receiver set forth in claim 9 wherein said last mentioned converting circuitry is shared between a plurality of channels.
Claim 11
Independent Claim
138 words
A method for determining a global positioning parameter from analog signal information received from a plurality of navigational satellites, said signal information having data shifts and frequency shifts dependent upon the distance and relative velocity between the satellite's transmission position and the geographical position of said receiver, and wherein said analog signal is significantly weaker than ambient atmospheric noise, said method comprising the steps of: accepting said analog signals from a plurality of said satellites and modulating said receiver analog signals into equivalent IF analog signals; converting said analog IF signals to digital signals prior to further processing of said IF signals; processing said digital signals for acquiring valid signals in the presence of said noise; estimating the correct position; and continually updating said estimate based upon data exchanged between said estimating function and said signal processing function.
Claim 12
Dependent Claim
18 words
The method set forth in claim 11 wherein converting includes the step of: implementing full null zone detection.
Claim 13
Dependent Claim
37 words
The method set forth in claim 11 wherein said analog satellite information is coded in P(Y)-code and in C/A code, and wherein said signal processing function includes: tracking both said information codes simultaneously on a single channel.
Claim 14
Dependent Claim
20 words
The method set forth in claim 11 wherein said estimating function includes: vector summing said acquired P(Y) and C/A codes.
Claim 15
Dependent Claim
32 words
The method set forth in claim 11 wherein said signal processing function includes the use of an offbeat oscillator frequency which allows for phase resolution of digital oscillators to process said P(Y)-code.
Claim 16
Dependent Claim
40 words
The method set forth in claim 11 further comprising the function of: tracking multiple channels simultaneously, said tracking including: assigning a different signal to each of several said channels; and time sharing a plurality of signals on said remainning channel.
Claim 17
Independent Claim
101 words
A system for acquiring signals from at least one global positioning system satellite, said system comprising: and analog receiver section for receiving said signals together with atmospheric noise and for developing an IF signal containing a spread spectrum of signals; circuitry for converting said IF signal to a digital equivalent; and circuitry for locking on to valid signals, said locking circuitry including: a digital signal processor; and a host computer for control and processing of data contained in said signal; said data containing information for allowing estimates to be made with respect to the frequency and data shifts of said signal.
Claim 18
Dependent Claim
34 words
The system set forth in claim 17 further comprising: circuitry for selectively adapting any channel on any of said signal processing circuits to process either or both P(Y) and C/A signals from said satellite.
Claim 19
Dependent Claim
45 words
The system set forth in claim 17 wherein each channel of said multi-channel signal processing circuit is operable for receiving both P(Y)-code and C/A code simultaneously, said system further including: circuitry for vector summing said P(Y) and C/A code to aid in tracking said signal.
Claim 20
Independent Claim
100 words
The method for acquiring signals from at least one satellite of a global positioning system, said method comprising the steps of: receiving said signals in analog form together with atmospheric noise and for developing an IF signal containing a spread spectrum of signals; converting said if signals to a digital equivalent; and locking onto valid signals, said locking step including the reiterative step of: estimating received signals with respect to frequency and code state of said signals with a processor, said estimates being compared with actual signals for allowing new estimates to be calculated so as to perform said locking.
Claim 21
Dependent Claim
19 words
The method set forth in claim 20 wherein said converting step includes the step of: performing null zone detection.
Claim 22
Dependent Claim
24 words
The method set forth in claim 20 wherein said method includes the step of: using an off beat oscillator frequency for resolving signal phase.
Claim 23
Dependent Claim
29 words
The method set forth in claim 20 wherein said locking step includes the use of a plurality of dual channel signal processing circuits each operable to perform said comparison.
Claim 24
Dependent Claim
32 words
The method set forth in claim 20 further comprising the step of: selectively adapting any channel on any of said processing circuits to receive P(Y) or C/A signals simultaneously from said satellite.
Claim 25
Dependent Claim
46 words
The method set forth in claim 20 wherein each channel said dual channel signal processing is operable for receiving both P(Y)-code and C/A code simultaneously, said method further including the step of: vector summing of said P(Y) and C/A code to aid in tracking said signal.
Claim 26
Dependent Claim
19 words
A receiver as claimed in claim 1 or claim 2 and wherein said parameter is position, velocity or time.
Claim 27
Dependent Claim
15 words
A method as claimed in claim 11 wherein said parameter is position, velocity or time.
References Cited (Backward Citations)
US4468793A
Cited
GB2155268A
Cited
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