Signal detector employing coherent integration

• US 6,917,331 B2
• Filed: 04/25/2003
• Issued: 07/12/2005
• Est. Priority Date: 03/30/1999
• Status: Expired due to Term

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: SIRF Technology Incorporated (Qualcomm, Inc.)
• Inventors: Gronemeyer, Steven
• Primary Examiner(s): PHAN, DAO LINDA
• Application Number:
  US10/423,137
• Publication Number:
  US 20030214434A1
• Time in Patent Office: 809 Days
• Field of Search: 342/89, 342/357.06, 342/378, 342/382, 701/213, 375/147, 375/150, 375/152, 375/254, 375/367
• US Class Current: 342/378
• CPC Class Codes: G01S 1/045 Receivers
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/29 carrier including Doppler, related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence

Abstract

A signal detector is provided in which complex samples of a received signal are multiplied by data representative of a hypothesis, and the resulting product data is coherently integrated over a desired duration to provide correlation data representative of the level of correlation between the hypothesis and the signal. In one embodiment, the signal detector is part of a GPS receiver.

Claims

1. A wireless communication device, comprising at least one component including at least one transceiver supporting voice communication, a Global Positioning System (GPS) receiver, and at least one signal processor, the components generating position information of the device by receiving at least one segment of a received signal, determining a location of at least one frame boundary and forming products between segment data and at least one hypothesis in response to at least one location of the at least one frame boundary, integrating the products using at least one integration selected in response to the location of the frame boundary, and generating cumulative correlation data using the integrated products and detecting the signals using the cumulative correlation data.

2. The device of claim 1, further comprising a phase detector that detects phase reversals of segments of the received signal.

3. The device of claim 1, wherein at least one of the components further determine phase information of each segment on first and second sides of the frame boundary, wherein the phase information indicates a phase reversal of the segment at the frame boundary, wherein integrating the products includes generating first correlation data by coherently integrating segment data on the first side of the frame boundary and generating second correlation data by coherently integrating segment data on the second side of the frame boundary, wherein generating cumulative correlation data includes controlling a sign of the first and second correlation data in response to the phase information and combining the first and second correlation data.

4. The device of claim 1, wherein integrating the products includes generating first correlation data by coherently integrating segment data on a first side of the frame boundary and generating second correlation data by coherently integrating segment data on a second side of the frame boundary, wherein generating cumulative correlation data includes noncoherently combining the first correlation data and the second correlation data.

5. The device of claim 1, wherein integrating the products further comprises:

generating first correlation data by coherently integrating segment data on a first side of the frame boundary using a first hypothesis;

generating second correlation data by coherently integrating segment data on the first side of the frame boundary using a second hypothesis; and

generating third correlation data by coherently integrating segment data on a second side of the frame boundary using a third hypothesis.

6. The device of claim 5, wherein generating cumulative correlation data further comprises:

combining the first correlation data and the third correlation data to form a first combined correlation;

combining the second correlation data and the third correlation data to form a second combined correlation; and

selecting one of the first and second combined correlations having a highest value for use in testing for signal presence.

7. The device of claim 1, wherein at least one of the components further determines the at least one frame boundary using at least one of the received signal and at least one signal source other than the received signal.

8. The device of claim 1, wherein the received signal is a carrier signal modulated with at least one code.

9. The device of claim 1, wherein at least one of the components further generate at least one hypothesis.

10. A communication system, comprising:

means for receiving at least one segment of a received signal;

means for determining a location of at least one frame boundary;

means for forming products between segment data and at least one hypothesis in response to at least one location of the at least one frame boundary;

means for integrating the products using at least one integration selected in response to the location of the frame boundary; and

means for generating cumulative correlation data using the integrated products and detecting the signals using the cumulative correlation data.

11. A method for detecting signals, comprising:

receiving at least one segment of a received signal;

determining a location of at least one frame boundary;

forming products between segment data and at least one hypothesis in response to at least one location of the at least one frame boundary;

integrating the products using at least one integration selected in response to the location of the frame boundary; and

generating cumulative correlation data using the integrated products and detecting the signals using the cumulative correlation data.

12. The method of claim 11, further comprising determining phase information of the segment on first and second sides of the frame boundary.

13. The method of claim 11, further comprising determining phase information of each segment on first and second sides of the frame boundary, wherein the phase information indicates a phase reversal of the segment at the frame boundary, wherein integrating the products includes generating first correlation data by coherently integrating segment data on the lust side of the frame boundary and generating second correlation data by coherently integrating segment data on the second side of the frame boundary, wherein generating cumulative correlation data includes controlling a sign of the first and second correlation data in response to the phase information and combining the first and second correlation data.

14. The method of claim 11, wherein integrating the products includes generating first correlation data by coherently integrating segment data on a first side of the frame boundary and generating second correlation data by coherently integrating segment data on a second side of the frame boundary, wherein generating cumulative correlation data includes noncoherently combining the first correlation data and the second correlation data.

15. The method of claim 11, wherein integrating the products further comprises:

generating first correlation data by coherently integrating segment data on a first side of the frame boundary using a first hypothesis;

generating second correlation data by coherently integrating segment data on the first side of the frame boundary using a second hypothesis; and

generating third correlation data by coherently integrating segment data on a second side of the frame boundary using a third hypothesis.

16. The method of claim 15, wherein generating cumulative correlation data further comprises:

combining the first correlation data and the third correlation data to form a first combined correlation;

combining the second correlation data and the third correlation data to form a second combined correlation; and

selecting one of the first and second combined correlations having a highest value for use in testing for signal presence.

17. The method of claim 11, further comprising determining a location of the at least one frame boundary using at least one of the received signal and at least one signal source other than the received signal.

18. The method of claim 11, wherein the received signal is a carrier signal modulated with at least one code.

19. The method of claim 11, further comprising generating at least one hypothesis.

20. The method of claim 11, wherein the received signal is a Global Positioning System (GPS) signal.

21. A method for detecting signals, comprising:

receiving at least one segment of a received signal;

determining a location of a frame boundary of the segment and determining phase information of the segment on first and second sides of the frame boundary;

forming products between segment data and at least one hypothesis;

integrating the products using at least one integration selected in response to the phase information; and

generating cumulative correlation data using the integrated products and the phase information and detecting the signals using the cumulative correlation data.

22. The method of claim 21, wherein the phase information indicates a phase reversal of the segment at the frame boundary, wherein integrating the products includes generating first correlation data by coherently integrating segment data on the first side of the frame boundary and generating second correlation data by coherently integrating segment data on the second side of the frame boundary, wherein generating cumulative correlation data includes reversing a sign of the second correlation data and combining the first and second correlation data.

23. A cellular telephone, comprising:

a voice communications system;

a Global Positioning System (GPS) receiver that receives GPS signals; and

at least one signal processing system coupled among the voice communications system and the GPS receiver, the signal processing system configured to perform at least one of detecting and tracking GPS signals, wherein at least one of the GPS receiver and the signal processing system receive at least one segment of a received signal, determine a location of at least one frame boundary and form products between segment data and at least one hypothesis in response to the location of the at least one frame boundary, integrate the products using at least one integration selected in response to the location of the frame boundary, and generate cumulative correlation data using the integrated products and detect the signals using the cumulative correlation data.

24. The telephone of claim 23, further comprising:

at least one phase detector for detecting phase reversals of the signal of interest; and

at least one integrator that adjusts for detected phase reversals to proceed with coherent integration across a frame boundary.

25. The telephone of claim 23, further comprising at least one integrator that generates first correlation data by coherently integrating the products data across the frame boundary under a first hypothesis that assumes a phase of the received signal is unchanged across the frame boundary, and generates second correlation data by coherently integrating the products data across the frame boundary under a second hypothesis that assumes the phase of the received signal reverses across the frame boundary.

26. The telephone of claim 23, further comprising:

at least one coherent integrator that generates first correlation data by coherently integrating the products data on a first side of the frame boundary and generates second correlation data by coherently integrating segment data on a second side of the frame boundary; and

at least one noncoherent integrator that noncoherently combines the first correlation data and the second correlation data.

27. The telephone of claim 23, further comprising at least one integrator that integrates the products by:

generating first correlation data by coherently integrating segment data on a first side of the frame boundary using a first hypothesis;

generating second correlation data by coherently integrating segment data on the first side of the frame boundary using a second hypothesis; and

generating third correlation data by coherently integrating segment data on a second side of the frame boundary using a third hypothesis.

28. The telephone of claim 27, wherein generating cumulative correlation data further comprises:

combining the first correlation data and the third correlation data to form a first combined correlation;

combining the second correlation data and the third correlation data to form a second combined correlation; and

selecting one of the first and second combined correlations having a highest value for use in testing for signal presence.

29. Computer readable media including instructions which, when executed in a processing system, perform at least one of detecting and tracking signals, by:

receiving at least one segment of a received signal;

determine a location of at least one frame boundary;

forming products between segment data and at least one hypothesis in response to at least one location of the at least one frame boundary;

integrating the products using at least one integration selected in response to the location of the frame boundary; and

generating cumulative correlation data using the integrated products and detecting the signals using the cumulative correlation data.

30. The media of claim 29, wherein detecting and tracking signals further comprises determining phase information of the segment on first and second sides of the frame boundary.

31. The media of claim 29, wherein detecting and tracking signals further comprises determining phase information of each segment on first and second sides of the frame boundary, wherein the phase information indicates a phase reversal of the segment at the frame boundary, wherein integrating the products includes generating first correlation data by coherently integrating segment data on die first side of the frame boundary and generating second correlation data by coherently integrating segment data on the second side of the frame boundary, wherein generating cumulative correlation data includes controlling a sign of the first and second correlation data in response to the phase information and combining the first and second correlation data.

32. The media of claim 29, wherein integrating the products includes generating first correlation data by coherently integrating segment data on a first side of the frame boundary and generating second correlation data by coherently integrating segment data on a second side of the frame boundary, wherein generating cumulative correlation data includes noncoherently combining the first correlation data and the second correlation data.

33. The media of claim 29, wherein integrating the products further comprises:

generating first correlation data by coherently integrating segment data on a first side of the frame boundary using a first hypothesis;

generating second correlation data by coherently integrating segment data on the first side of the frame boundary using a second hypothesis; and

generating third correlation data by coherently integrating segment data on a second side of the frame boundary using a third hypothesis.

34. The media of claim 33, wherein generating cumulative correlation data further comprises:

combining the first correlation data and the third correlation data to form a first combined correlation;

combining the second correlation data and the third correlation data to form a second combined correlation; and

selecting one of the first and second combined correlations having a highest value for use in testing for signal presence.