METHOD AND DEVICE FOR CONTINUOUS WAVE RADAR MEASUREMENTS

• US 20130127652A1
• Filed: 07/07/2011
• Published: 05/23/2013
• Est. Priority Date: 07/16/2010
• Status: Active Grant

• Current Assignee: Sivers Wireless AB (Sivers Semiconductors AB)
• Original Assignee: Sivers IMA AB (Sivers Semiconductors AB)
• Inventors: Bruce, Staffan
• Granted Patent: US 8,994,583 B2
• Time in Patent Office: Days
• US Class Current: 342/109
• CPC Class Codes: G01S 13/584 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 13/825 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/84 for distance determination by phase measurement
• CPC Class Codes: G01S 5/0009 Transmission of position information to remote stations involving assistance data G01S5/0236
• CPC Class Codes: G01S 5/0072 Transmission between mobile stations, e.g. anti-collision systems
• CPC Class Codes: G01S 5/0284 Relative positioning

Abstract

This invention relates to a method for determining at least one of a distance and a relative velocity by means of continuous wave radar measurements. The method includes generating a measurement signal in the form of a continuous wave radar signal; transmitting the measurement signal by means of an antenna (112); reflecting the measurement signal by means of a reflector (118), thereby providing a desired reflected measurement signal; receiving the desired reflected measurement 112 signal; and determining at least one of a distance and a relative velocity between the antenna and the reflector by means of the desired reflected measurement signal. The reflection of the measurement signal involves asymmetrically modulating the measurement signal at the reflector. The determination of at least one of a distance and a relative velocity includes detecting the desired reflected measurement signal among several received reflections of the measurement signal, by means of information added by the asymmetric modulation.

Claims

1. A method for determining at least one of a distance and a relative velocity by means of continuous wave radar measurements, comprising:

generating a measurement signal in the form of a continuous wave radar signal;

transmitting the measurement signal by means of an antenna;

reflecting the measurement signal by means of a reflector, thereby providing a desired reflected measurement signal;

receiving the desired reflected measurement signal; and

determining at least one of a distance and a relative velocity between the antenna and the reflector by means of the desired reflected measurement signal, wherein

said reflecting the measurement signal comprising asymmetrically modulating the measurement signal at the reflector, comprising applying a modulation signal which alternates between a first state and a second state, the duration of the first state differing from the duration of the second state; and

said determining at least one of a distance and a relative velocity comprising identifying the desired reflected measurement signal, among several received reflections of the measurement signal, by means of the asymmetric modulation.

2. The method according to claim 1, wherein said asymmetrically modulating the measurement signal at the reflector comprises asymmetrically phase modulating the measurement signal.

3. The method according to claim 1, wherein said asymmetrically modulating the measurement signal at the reflector comprises asymmetrically amplitude modulating the measurement signal.

4. The method according to claim 1, wherein said determining at least one of a distance and a relative velocity comprises detecting a phase difference between the desired reflected measurement signal and the transmitted measurement signal.

5. The method according to claim 4, further comprising generating a phase value as one of a cosine and a sine value of the phase difference.

6. The method according to claim 1, wherein said determining at least one of a distance and a relative velocity comprises identifying the first and second states and their different durations in the desired reflected measurement signal.

7. The method according to claim 6, wherein said first and second states are provided as one of different phase shifts and different amplitude levels.

8. The method according to claim 6, wherein said identifying the first and second states comprises studying a phase value during an integer number of periods of the asymmetric modulation.

9. A device for determining at least one of a distance and a relative velocity by means of continuous wave radar measurements, comprising a transceiver device and a reflector device, wherein the transceiver device comprises:

a measurement signal generator, arranged to generate a measurement signal in the form of a continuous wave radar signal; and

a transmitter, arranged to transmit the measurement signal, wherein the reflector device comprises;

a reflector, arranged to reflect the transmitted measurement signal; and

a modulator for modulating the measurement signal in conjunction with reflecting it, thereby providing a desired reflected measurement signal, wherein the transceiver device further comprises;

a receiver, arranged to receive the desired reflected measurement signal; and

a controller, arranged to determine at least one of a distance and a relative velocity between the transmitter and the reflector, characterized in that;

the modulator is arranged to asymmetrically modulate the measurement signal, wherein the reflector device comprises a modulator controller arranged to switch the modulator between a first state and a second state, the duration of the first state differing from the duration of the second state; and

in that

the controller is arranged to identify the desired reflected measurement signal, among several received reflections of the measurement signal, by means of the asymmetric modulation.

10. The device according to claim 9, wherein the modulator comprises a phase modulator.

11. The device according to claim 9, wherein the detector comprises a phase detector, arranged to detect a phase difference between the measurement signal and the desired reflected measurement signal, the phase detector being connected with the controller for providing it with information about said phase difference.

12. The device according to claim 9, wherein the detector comprises an amplitude detector.

13. The device according to claim 9, wherein said controller is arranged to identify the desired reflected measurement signal by identifying the first and second states and their different durations in the desired reflected measurement signal.

14. The device according to claim 9, comprising a stop device, which is arranged to control stopping of a movable object on basis of a determined distance.