Receiver for a frequency-shift-keying, continuous-wave radar

• US 6,618,449 B1
• Filed: 02/24/1999
• Issued: 09/09/2003
• Est. Priority Date: 03/03/1998
• Status: Expired due to Term

• Current Assignee: Beijing Voyager Technology Co., Ltd.
• Original Assignee: Thomson-CSF
• Inventors: Cornic, Pascal, Laviec, Philippe
• Primary Examiner(s): PHU, PHUONG M
• Application Number:
  US09/256,214
• Time in Patent Office: 1,658 Days
• Field of Search: 375/334, 375/335, 375/337, 375/272, 375/275, 375/219, 329/300, 329/301, 329/302, 329/303, 455/73, 455/84
• US Class Current: 375/335
• CPC Class Codes: G01S 13/32 using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 7/352 Receivers
• CPC Class Codes: G01S 7/4021 of receivers

Abstract

A receiver of a frequency-shift-keying, continuous-wave radar comprises at least sampling means taking real samples of the signals in each reception channel and extrapolation means, the extrapolation means producing fictitious samples synchronous with the real samples, the reception signals being formed out of real samples and fictitious samples. Application especially to radars fitted into automobiles.

Claims

1. A receiver for a frequency-shift-keying continuous-wave radar transmitting in several frequencies and comprising several corresponding reception channels for receiving signals, wherein said receiver comprises:

sampling means for taking real samples of the signals in each reception channel; and

extrapolation means for producing fictitious samples synchronous with the real samples,

wherein reception signals are formed out of the real samples and the fictitious samples.

2. A receiver according to claim 1, wherein the fictitious samples have a zero value.

3. A receiver according to claim 1, wherein the fictitious samples are equal to a last sampled real value.

4. A receiver according to claim 1, wherein the fictitious samples are obtained by a linear extrapolation of the real samples.

5. A receiver according to claim 1, further comprising filtering means at an output of the extrapolation means for filtering the fictitious samples.

6. A receiver according to claim 5, wherein the filtering means are digital.

7. A receiver according to claim 6, wherein the filtering means is non-recursive.

8. A receiver according to claim 1, wherein an extrapolation of the real samples by the fictitious samples is done at each radar recurrence.

9. A receiver according to claim 1, wherein the sampling means are contained in an analog-digital converter.

10. A receiver according to claim 1, further comprising, upline from the sampling means, a matched filter whose cut-off frequency is smaller than or equal to a sampling frequency divided by two.

11. A receiver according to claim 1, wherein the radar sends and receives in five frequencies, F0, F1, F2, F3, F4.

12. A receiver according to claim 11, wherein the five frequencies F0, F1, F2, F3, F4 verify the following relationships:

13. A receiver according to claim 11, wherein the frequency band of the radar ranges from 76 to 77 GHz.

14. A receiver according to claim 11, equipping an automobile vehicle.

15. A receiver according to claim 1, that is a homodyne type receiver.

16. A method of processing a frequency-shift-keyed continuous-wave signal received in a radar, comprising:

receiving a return signal in reception channels respectively corresponding to a plurality of transmitted frequencies;

frequency-shift-keying the return signal;

sampling real samples of the return signal in each of the reception channels;

extrapolating the real samples to produce fictitious samples synchronous with the real samples; and

forming reception signals out of said real samples and said fictitious samples.

17. A method according to claim 16, wherein the extrapolating step results in a plurality of fictitious samples for each pair of said real samples.

18. A method according to claim 17, further comprising:

performing a Fourier transformation following the extrapolating step.

19. A receiver for a frequency-shift-keying continuous-wave radar transmitting in several frequencies and including several corresponding reception channels for receiving channels, said receiver comprising:

a sampling mechanism configured to obtain real samples of the signals in each reception channel; and

an extrapolation mechanism configured to produce fictitious samples synchronous with the real samples,

wherein reception signals are formed out of the real samples and the fictitious samples.

20. A receiver according to claim 19, wherein the fictitious samples have a zero value.

21. A receiver according to claim 19, wherein the fictitious samples are equal to a last sampled real value.

22. A receiver according to claim 19, wherein the fictitious samples are obtained by a linear extrapolation of the real samples.

23. A receiver according to claim 19, further comprising a filter at an output of the extrapolation mechanism and configured to filter the fictitious signals.

24. A receiver according to claim 23, wherein the filter comprises a digital filter.

25. A receiver according to claim 24, wherein the filter is nonrecursive.

26. A receiver according to claim 19, wherein an extrapolation of the real samples by the fictitious samples is done at each radar recurrence.

27. A receiver according to claim 19, wherein the sampling mechanism is contained in an analog-digital converter.

28. A receiver according to claim 19, further comprising, upline from the sampling mechanism, a matched filter whose cut-off frequency is smaller than or equal to a sampling frequency divided by two.

29. A receiver according to claim 19, wherein the radar sends and receives in five frequencies, F0, F1, F2, F3, F4.

30. A receiver according to claim 29, wherein the five frequencies F0, F1, F2, F3, F4 verify the following relationships:

31. A receiver according to claim 29, wherein the frequency band of the radar ranges from 76 to 77 GHz.

32. A receiver according to claim 29, wherein the receiver is installed in an automobile.

33. A receiver according to claim 19, wherein the receiver comprises a homodyne type receiver.