TWO-WAY RANGING MESSAGING SCHEME

• US 20110292820A1
• Filed: 09/03/2010
• Published: 12/01/2011
• Est. Priority Date: 05/26/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ekbal, Amal, Julian, David Jonathan, Budianu, Petru Cristian
• Granted Patent: US 8,879,407 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location

Abstract

In a two-way ranging scheme where a first apparatus (e.g., device) determines a distance to a second apparatus (e.g., device), specified packets are sent between these apparatuses at specified times to facilitate the determination of the distance. In some aspects, these packets may be defined and/or sent in a manner that enables the apparatuses to detect a leading edge of a received packet with a high degree of accuracy. For example, an apparatus may transmit a packet a defined period of time after transmitting or receiving another packet. In addition, a packet may comprise a defined symbol sequence that is used by an apparatus that receives the packet to identify a leading edge of the packet.

Claims

1. A method of wireless communication, comprising:

receiving a first packet from a first apparatus at a second apparatus;

transmitting a second packet from the second apparatus to the first apparatus after the reception of the first packet;

receiving a third packet from the first apparatus as a result of the transmission of the second packet;

generating first information indicative of a first time value associated with the transmission of the second packet and a second time value associated with the reception of the third packet; and

transmitting the first information to the first apparatus to enable the first apparatus to determine a distance between the first apparatus and the second apparatus.

2. The method of claim 1, wherein the second packet is transmitted a defined period of time after the reception of the first packet.

3. The method of claim 1, wherein:

the third packet comprises a first symbol sequence for a leading edge detection operation at the second apparatus; and

the generation of the first information further comprises determining the second time value by detecting a leading edge associated with the first symbol sequence and determining a time of arrival of the leading edge.

4. The method of claim 3, wherein the first symbol sequence comprises the beginning of the third packet.

5. The method of claim 3, wherein the second packet comprises a second symbol sequence for a leading edge detection operation at the first apparatus.

6. The method of claim 1, further comprising:

receiving a fourth packet from the first apparatus, wherein the fourth packet comprises a first symbol sequence for gain control at the second apparatus;

transmitting a fifth packet from the second apparatus to the first apparatus as a result of the reception of the fourth packet; and

determining a gain level for the reception of the first packet based on the first symbol sequence.

7. The method of claim 6, further comprising:

initiating a ranging operation at the second apparatus; and

initiating the gain control at the second apparatus as a result of the initiation of the ranging operation at the second apparatus.

8. The method of claim 6, wherein the fourth packet further comprises a second symbol sequence for clock drift estimation at the second apparatus.

9. The method of claim 8, wherein the first and second time values are calculated based on a clock that is adjusted based on the clock drift estimation.

10. The method of claim 1, further comprising:

receiving second information from the first apparatus as a result of the transmission of the first information; and

determining the distance between the first and second apparatuses based on the received second information.

11. The method of claim 1, further comprising:

initiating a ranging operation at the second apparatus; and

establishing at least one ranging channel as a result of the initiation of the ranging operation, wherein the at least one ranging channel is established for the reception of at least the first and third packets and the transmission of at least the second packet.

12. The method of claim 11, wherein the establishment of the at least one ranging channel comprises defining at least one of the group consisting of:

a pulse repetition period and a pulse time hopping sequence.

13. An apparatus for wireless communication, comprising:

a receiver configured to receive a first packet from another apparatus;

a transmitter configured to transmit a second packet to the another apparatus after the reception of the first packet, wherein the receiver is further configured to receive a third packet from the another apparatus as a result of the transmission of the second packet; and

a ranging controller configured to generate first information indicative of a first time value associated with the transmission of the second packet and a second time value associated with the reception of the third packet, wherein the transmitter is further configured to transmit the first information to the another apparatus to enable the another apparatus to determine a distance between the another apparatus and the apparatus.

14. The apparatus of claim 13, wherein the second packet is transmitted a defined period of time after the reception of the first packet.

15. The apparatus of claim 13, wherein:

the third packet comprises a first symbol sequence for a leading edge detection operation at the apparatus; and

the generation of the first information further comprises determining the second time value by detecting a leading edge associated with the first symbol sequence and determining a time of arrival of the leading edge.

16. The apparatus of claim 15, wherein the first symbol sequence comprises the beginning of the third packet.

17. The apparatus of claim 15, wherein the second packet comprises a second symbol sequence for a leading edge detection operation at the another apparatus.

18. The apparatus of claim 13, wherein:

the receiver is further configured to receive a fourth packet from the another apparatus;

the fourth packet comprises a first symbol sequence for gain control at the apparatus;

the transmitter is further configured to transmit a fifth packet to the first apparatus as a result of the reception of the fourth packet; and

the apparatus further comprises a gain controller configured to determine a gain level for the reception of the first packet based on the first symbol sequence.

19. The apparatus of claim 18, wherein:

the ranging controller is further configured to initiate a ranging operation at the apparatus; and

the gain controller is further configured to initiate the gain control at the apparatus as a result of the initiation of the ranging operation.

20. The apparatus of claim 18, wherein the fourth packet further comprises a second symbol sequence for clock drift estimation at the apparatus.

21. The apparatus of claim 20, wherein the first and second time values are calculated based on a clock that is adjusted based on the clock drift estimation.

22. The apparatus of claim 13, wherein:

the receiver is further configured to receive second information from the another apparatus as a result of the transmission of the first information; and

the ranging controller is further configured to determine the distance between the first and second apparatuses based on the received second information.

23. The apparatus of claim 13, wherein:

the ranging controller is further configured to initiate a ranging operation at the apparatus;

the apparatus further comprises a communication controller configured to establish at least one ranging channel as a result of the initiation of the ranging operation; and

the at least one ranging channel is established for the reception of at least the first and third packets and the transmission of at least the second packet.

24. The apparatus of claim 23, wherein the establishment of the at least one ranging channel comprises defining at least one of the group consisting of:

a pulse repetition period and a pulse time hopping sequence.

25. An apparatus for wireless communication, comprising:

means for receiving a first packet from another apparatus;

means for transmitting a second packet to the another apparatus after the reception of the first packet, wherein the means for receiving is configured to receive a third packet from the another apparatus as a result of the transmission of the second packet; and

means for generating first information indicative of a first time value associated with the transmission of the second packet and a second time value associated with the reception of the third packet, wherein the means for transmitting is configured to transmit the first information to the another apparatus to enable the another apparatus to determine a distance between the another apparatus and the apparatus.

26. The apparatus of claim 25, wherein the second packet is transmitted a defined period of time after the reception of the first packet.

27. The apparatus of claim 25, wherein:

the third packet comprises a first symbol sequence for a leading edge detection operation at the apparatus; and

the generation of the first information further comprises determining the second time value by detecting a leading edge associated with the first symbol sequence and determining a time of arrival of the leading edge.

28. The apparatus of claim 27, wherein the first symbol sequence comprises the beginning of the third packet.

29. The apparatus of claim 27, wherein the second packet comprises a second symbol sequence for a leading edge detection operation at the another apparatus.

30. The apparatus of claim 25, wherein:

the means for receiving is configured to receive a fourth packet from the another apparatus;

the fourth packet comprises a first symbol sequence for gain control at the apparatus;

the means for transmitting is configured to transmit a fifth packet to the first apparatus as a result of the reception of the fourth packet; and

the apparatus further comprises means for determining a gain level for the reception of the first packet based on the first symbol sequence.

31. The apparatus of claim 30, further comprising:

means for initiating a ranging operation at the apparatus; and

means for initiating the gain control at the apparatus as a result of the initiation of the ranging operation.

32. The apparatus of claim 30, wherein the fourth packet further comprises a second symbol sequence for clock drift estimation at the apparatus.

33. The apparatus of claim 32, wherein the first and second time values are calculated based on a clock that is adjusted based on the clock drift estimation.

34. The apparatus of claim 25, wherein:

the means for receiving is configured to receive second information from the another apparatus as a result of the transmission of the first information; and

the apparatus further comprises means for determining the distance between the first and second apparatuses based on the received second information.

35. The apparatus of claim 25, further comprising:

means for initiating a ranging operation at the apparatus;

means for establishing at least one ranging channel as a result of the initiation of the ranging operation, wherein the at least one ranging channel is established for the reception of at least the first and third packets and the transmission of at least the second packet.

36. The apparatus of claim 35, wherein the establishment of the at least one ranging channel comprises defining at least one of the group consisting of:

a pulse repetition period and a pulse time hopping sequence.

37. A computer-program product for wireless communication, comprising:

computer-readable medium comprising codes executable to;

receive a first packet from a first apparatus at a second apparatus;

transmit a second packet from the second apparatus to the first apparatus after the reception of the first packet;

receive a third packet from the first apparatus as a result of the transmission of the second packet;

generate first information indicative of a first time value associated with the transmission of the second packet and a second time value associated with the reception of the third packet; and

transmit the first information to the first apparatus to enable the first apparatus to determine a distance between the first apparatus and the second apparatus.

38. A headset, comprising:

a receiver configured to receive a first packet from an apparatus;

a transmitter configured to transmit a second packet to the apparatus after the reception of the first packet, wherein the receiver is further configured to receive a third packet from the apparatus as a result of the transmission of the second packet;

a ranging controller configured to generate first information indicative of a first time value associated with the transmission of the second packet and a second time value associated with the reception of the third packet, wherein the transmitter is further configured to transmit the first information to the apparatus to enable the apparatus to determine a distance between the headset and the apparatus; and

a transducer configured to provide an audio output based on the first information.

39. A watch, comprising:

a receiver configured to receive a first packet from an apparatus;

a transmitter configured to transmit a second packet to the apparatus after the reception of the first packet, wherein the receiver is further configured to receive a third packet from the apparatus as a result of the transmission of the second packet;

a ranging controller configured to generate first information indicative of a first time value associated with the transmission of the second packet and a second time value associated with the reception of the third packet, wherein the transmitter is further configured to transmit the first information to the apparatus to enable the apparatus to determine a distance between the watch and the apparatus; and

a user interface configured to provide an indication based on the first information.

40. A sensing device, comprising:

a receiver configured to receive a first packet from an apparatus;

a transmitter configured to transmit a second packet to the apparatus after the reception of the first packet, wherein the receiver is further configured to receive a third packet from the apparatus as a result of the transmission of the second packet;

a ranging controller configured to generate first information indicative of a first time value associated with the transmission of the second packet and a second time value associated with the reception of the third packet, wherein the transmitter is further configured to transmit the first information to the apparatus to enable the apparatus to determine a distance between the sensing device and the apparatus; and

a sensor configured to provide data for transmission as a result of the generation of the first information.