Asymmetric double-sided two-way ranging in an ultrawideband communication system

• US 10,488,509 B2
• Filed: 05/12/2016
• Issued: 11/26/2019
• Est. Priority Date: 05/12/2015
• Status: Active Grant

• Current Assignee: DecaWave Limited (Qorvo, Inc.)
• Original Assignee: DecaWave Limited (Qorvo, Inc.)
• Inventors: McLaughlin, Michael, Verso, Billy
• Primary Examiner(s): Magloire, Vladimir
• Assistant Examiner(s): Braswell, Donald H B
• Application Number:
  US15/500,633
• Publication Number:
  US 20180059235A1
• Time in Patent Office: 1,293 Days
• CPC Class Codes: G01S 13/20 whereby multiple time-around echoes are used or eliminated
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/767 Responders; Transponders teaching or practice apparatus for gun-aiming or gun-laying using reflecting targets or active targets F41G3/26
• CPC Class Codes: G01S 13/785 Distance Measuring Equipment [DME] systems
• CPC Class Codes: H01Q 5/25 Ultra-wideband [UWB] systems, e.g. multiple resonance systems; Pulse systems

Abstract

In an ultra-wideband (“UWB”) communication system comprising a pair of UWB transceivers, an asynchronous two-way ranging method for closely estimating the time-of-flight between the transceivers after the exchange of only 3 messages between the transceivers. In an alternate asynchronous two-way ranging method, the time-of-flight between the transceivers may be closely estimated after the exchange of only 4 messages between the transceivers.

Claims

1. An asymmetric double-sided two-way ranging method using three messages, P₁, P₂, and P₃, to complete a pair of round-trip delay measurements between a first device, A, having a first clock, C_a, and a second device, B, having a second clock, C_b, the method comprising the steps of:

[1.1] in A, transmitting P₁ at a selected point in time T₀ relative to C_a;

[1.2] in B;

[1.2.1] after an unknown time-of-flight, T_f, receiving P₁ at a time T₁ relative to C_b; and

[1.2.2] after a first transmit delay, {circumflex over (D)}_b, transmitting P₂ at a time T₂ relative to C_b;

[1.3] in A;

[1.3.1] after a first response delay, {circumflex over (R)}_a, relative to T₀, receiving P₂ at a time T₃ relative to C_a; and

[1.3.2] after a second transmit delay, {circumflex over (D)}_a, transmitting P₃ at a time T₄ relative to C_a; and

[1.4] in B;

[1.4.1] after a second response delay, {circumflex over (R)}_b, relative to T₂, receiving P₃ at a time T₅ relative to C_b; and

[1.4.2] developing an estimate, {tilde over (T)}_f, of T_f in accordance with a selected one of;

2. The method of claim 1 further including the step of:

[1.4.3] developing an estimate of a distance between A and B as a function of {tilde over (T)}_f.

5. An asymmetric two-way ranging circuit configured to perform the method of any preceding claim.

6. A wireless receiver comprising an asymmetric two-way ranging circuit according to claim 5.

7. A wireless transceiver comprising a wireless receiver according to claim 6.

8. A wireless communication system comprising a wireless transceiver according to claim 7.

9. A non-transitory computer readable medium including executable instructions which, when executed in a processing system, causes the processing system to perform the steps of a method according to any one of claims 1 to 4.

3. An asymmetric double-sided two-way ranging method using four messages, P₁, P₂, P₃ and P₄, to complete a pair of round-trip delay measurements between a first device, A, having a first clock, C_a, and a second device, B, having a second clock, C_b, the method comprising the steps of:

[3.1] in A, transmitting P₁ at a selected point in time T₀ relative to C_a;

[3.2] in B;

[3.2.1] after an unknown time-of-flight, T_f, receiving P₁ at a time T₁ relative to C_b; and

[3.2.2] after a first transmit delay, {circumflex over (D)}_b, transmitting P₂ at a time T₂ relative to C_b;

[3.3] in A;

[3.3.1] after a first response delay, {circumflex over (R)}_a, relative to T₀, receiving P₂ at a time T₃ relative to C_a;

[3.4] in B, transmitting P₃ at a selected point in time T₄ relative to C_b;

[3.5] in A;

[3.5.1] after an unknown time-of-flight, T_f, receiving P₃ at a time T₅ relative to C_a; and

[3.5.2] after a second transmit delay, {circumflex over (D)}_a, transmitting P₄ at a time T₆ relative to C_a; and

[3.6] in B;

[3.6.1] after a second response delay, {circumflex over (R)}_b, relative to T₄, receiving P₄ at a time T₇ relative to C_b; and

[3.6.2] developing an estimate, {tilde over (T)}_f, of T_f in accordance with a selected one of;

4. The method of claim 3 further including the step of:

[3.6.3] developing an estimate of a distance between A and B as a function of {tilde over (T)}_f.