Transmission path identification based on propagation channel diversity

• US 10,418,861 B2
• Filed: 12/22/2017
• Issued: 09/17/2019
• Est. Priority Date: 12/22/2017
• Status: Active Grant

• Current Assignee: Ossia, Inc.
• Original Assignee: Ossia, Inc.
• Inventors: Zeine, Hatem Ibrahim, Moghaddam, Ahmad
• Primary Examiner(s): Fleming, Fritz M
• Application Number:
  US15/852,348
• Publication Number:
  US 20190199145A1
• Time in Patent Office: 634 Days
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
• CPC Class Codes: H02J 50/27 characterised by the type of receiving antennas, e.g. rectennas
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H04B 17/12 of transmit antennas, e.g. of the amplitude or phase
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04B 7/02 Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas RAKE receivers H04B1/7115
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0671 using different delays between antennas

Abstract

Various embodiments of the present technology relate generally to wireless power systems. More specifically, some embodiments relate to the use of time reversal techniques utilizing time diversity (e.g., different multipath arrivals at the same antenna) to achieve coherency from the same transmission node. For example, instead of initiating outgoing transmissions (e.g., power signals) at the same time, various embodiments can initiate the outgoing signals from the various antennas in a staggered timing that is a reversal of the arrival times of an incoming signal. As a result of staggering the start of the outgoing signals, the signals will arrive at the destination at approximately the same time even though they have traveled different paths having different propagation delays.

Claims

1. A method comprising:

receiving, at an array of antennas, a wireless signal from a client device;

recording the wireless signal received at each antenna in the array of antennas; and

generating a coherent transmission signal to be sent to the client device from the array of antennas, wherein the coherent transmission signal is created by transmitting the coherent transmission signal at each antenna in a reverse order of the wireless signal received at each of the array of antennas.

2. The method of claim 1, further comprising recording a magnitude of the wireless signal received at each antenna in the array of antennas, and wherein generating the coherent transmission signal includes adjusting corresponding magnitudes of the coherent transmission signal in the array of antennas.

3. The method of claim 1, wherein the array of antennas is an adaptively-phase antenna array and the method further comprises identifying side echoes and estimating a full channel response by removing any identified side echoes.

4. The method of claim 1, wherein the wireless signal is a beacon signal and the coherent transmission signal is a response to the beacon signal.

5. The method of claim 1, further comprising:

recording at least a portion of the wireless signal from the client device at each antenna; and

creating an arrival sequence based on the wireless signal recorded at each antenna that is reversed to generate the coherent transmission signal.

6. The method of claim 1, further comprising creating a propagation channel profile based on the wireless signal recorded at each antenna in the array of antennas by identifying one or more phases of the wireless signal at each antenna.

7. The method of claim 6, wherein the wireless signal transmitted from the client device takes multiple paths that arrive at the array of antennas at different times.

8. A wireless power transmission system comprising:

an antenna array having multiple radio frequency (RF) antennas; and

control circuitry operatively coupled to the multiple RF antennas, the control circuitry configured to;

record arrival of a wireless signal from a client device at each of the RF antennas in the antenna array;

generate an arrival profile based, at least in part, on the arrival of the wireless signal at each RF antenna in the antenna array; and

send, from the antenna array, a transmission signal to the client device by reversing the wireless signal.

9. The wireless power transmission system of claim 8, further comprising a memory, and wherein the control circuitry is further configured to record, in the memory, at least a portion of the wireless signal in a time domain and identifies an arrival sequence.

10. The wireless power transmission system of claim 8, wherein the wireless signal is in a multipath environment and the control circuitry is further configured to identify a timing offset for each RF antenna.

11. The wireless power transmission system of claim 8, further comprising a signal generator to process the wireless signal and generate the transmission signal.

12. The wireless power transmission system of claim 8, wherein the arrival profile also includes a magnitude and phase of the wireless signal received at each RF antenna in the antenna array, and wherein to send the transmission signal the control circuitry adjusts, based on the arrival profile, the magnitude and phase of each transmission from the multiple RF antennas.

13. The wireless power transmission system of claim 8, wherein the control circuitry is further configured to identify side echoes and estimate a full channel response by removing any identified side echoes.

14. The wireless power transmission system of claim 8, wherein the transmission signal is a time reversed version of the wireless signal.

15. A computer-readable storage medium containing a set of instructions that when executed by one or more processors cause a machine to:

monitor multiple antennas of a wireless power transmission system within a multipath environment;

determine, upon receiving a wireless signal, an arrival profile of the wireless signal received via the multiple antennas of the wireless power transmission system;

calibrating the multiple antennas by setting a timing offset of each antenna of the multiple antennas;

generate a transmission profile based at least in part on a time reversal of the arrival profile and timing offset of each antenna; and

sending a transmission signal using the transmission profile such that the transmission signal is emitted from the multiple antennas of the wireless power transmission system based on the transmission profile.

16. The computer-readable storage medium of claim 15, wherein the set of instructions further cause the machine to determine a phase and magnitude of the wireless signal at each of the multiple antennas.

17. The computer-readable storage medium of claim 16, wherein the phase and magnitude of the wireless signal are stored as part of the arrival profile.

18. The computer-readable storage medium of claim 17, wherein the set of instructions further cause the one or more processors to store at least a portion of the wireless signal.

19. The computer-readable storage medium of claim 17, wherein the set of instructions further cause the machine to identify side echoes and estimate a full channel response by removing any identified side echoes.

20. The computer-readable storage medium of claim 15, wherein the set of instructions further cause the machine to identify the wireless signal by using a pattern matching analysis.