Distributed wireless power transmission system
The embodiments described herein comprise a distributed wireless power transmission system including a plurality of wireless power transmission systems (WPTSs) coordinating transmissions to create a virtual WPTS. The plurality of WPTS coordinate amongst each other to compensate for local phase shift differences between respective clock sources so that transmissions from the WPTSs constructively interfere at a wireless power receiver client (WPRC).
1. A method performed by a first wireless power transmission system (WPTS), the method comprising:
transmitting a beacon from one or more calibration antennas of the first WPTS;
receiving the beacon at a reference antenna of the first WPTS;
receiving an indication of a phase of the beacon detected at a reference antenna of a second WPTS;
sending a signal to direct the second WPTS to send transmissions via its reference antenna at sequential phases;
concurrently receiving, at the one or more calibration antennas, at least one of the transmissions at sequential phases from the reference antenna of the second WPTS and a signal from the reference antenna of the first WPTS;
determining a sum received power of each of the received transmissions from the reference antenna of the second WPTS with the signal from the reference antenna of the first WPTS, wherein the determining includes identifying a calibration phase shift associated with a peak received power of the determined sums;
sending an indication of the calibration phase shift to the second WPTS; and
directionally transmitting first wireless power transmissions to a wireless power receive client (WPRC) in collaboration with the second WPTS, wherein the first wireless power transmissions at a location of the first WPTS are phase offset from second wireless power transmissions at a location of the second WPTS based on the calibration phase offset.
2. The method of claim 1 , further comprising communicating with the second WPTS to negotiate a master WPTS.
3. The method of claim 2 , further comprising determining the first WPTS to be the master WPTS based on the negotiating.
4. The method of claim 1 , wherein the concurrently directionally transmitting the first wireless power to the WPRC is done concurrently with the second wireless power transmissions from the second WPTS.
5. The method of claim 4 , wherein first wireless power transmissions constructively interfere with the second wireless power transmissions at a location of the WPRC.
6. The method of claim 1 , wherein the calibration phase offset adjusts a phase of a local oscillator of the second WPTS.
7. The method of claim 1 , wherein the signal to direct the second WPTS to send transmissions via its reference antenna at sequential phases indicates to the second WPTS to either sequentially increment or sequentially decrement the respective phases of the transmissions.
8. The method of claim 1 , further comprising:
receiving, at the reference antenna of the first WPTS, a WPRC beacon transmission from the WPRC; and
determining a phase of the WPRC beacon transmission as received at the first WPTS.
9. The method of claim 8 , further comprising receiving, from the second WPTS, an indication of a phase of the WPRC beacon transmission as received at the second WPTS.
10. The method of claim 8 , further comprising directionally transmitting third wireless power transmissions to the WPRC in collaboration with the second WPTS based on a detected phase of a peak received wireless power at the WPRC.
11. A first wireless power transmission system (WPTS), the first WPTS comprising:
a transceiver;
a plurality of antennas including one or more calibration antennas and a reference antenna;
the transceiver configured to transmit a beacon via the one or more calibration antennas;
the transceiver further configured to receive the beacon via the reference antenna;
the transceiver further configured to receive, via one or more antennas of the plurality of antennas, an indication of a phase of the beacon detected at a reference antenna of a second WPTS;
the transceiver further configured to send, via at least one antenna of the plurality of antennas, a signal to direct the second WPTS to send transmissions via its reference antenna at sequential phases;
the transceiver further configured to concurrently receive, via the one or more calibration antennas, at least one of the transmissions at sequential phases from the reference antenna of the second WPTS and a signal from the reference antenna of the first WPTS;
a processor configured to determine a sum received power of each of the received transmissions from the reference antenna of the second WPTS with the signal from the reference antenna of the first WPTS, and to identify a calibration phase shift associated with a peak received power of the determined sums;
the transceiver further configured to send, via the at least one antenna, an indication of the calibration phase shift to the second WPTS; and
the transceiver further configured to directionally transmit, via at least some of the plurality of antennas, first wireless power transmissions to a wireless power receive client (WPRC) in collaboration with the second WPTS, wherein the first wireless power transmissions at a location of the first WPTS are phase offset from second wireless power transmissions at a location of the second WPTS based on the calibration phase offset.
12. The first WPTS of claim 11 , wherein transceiver is further configured to communicate, via the at least one antenna, with the second WPTS to negotiate a master WPTS.
13. The first WPTS of claim 12 , wherein the processor is further configured to determine the first WPTS to be the master WPTS based on the negotiating.
14. The first WPTS of claim 11 , wherein the transceiver is further configured to directionally transmit, via the at least some of the plurality of antennas, the first wireless power to the WPRC concurrently with the second wireless power transmissions from the second WPTS.
15. The first WPTS of claim 14 , wherein first wireless power transmissions constructively interfere with the second wireless power transmissions at a location of the WPRC.
16. The first WPTS of claim 11 , wherein the calibration phase offset adjusts a phase of a local oscillator of the second WPTS.
17. The first WPTS of claim 11 , wherein the signal to direct the second WPTS to send transmissions via its reference antenna at sequential phases indicates to the second WPTS to either sequentially increment or sequentially decrement the respective phases of the transmissions.
18. The first WPTS of claim 11 , wherein:
the transceiver is further configured to receive, via the reference antenna, a WPRC beacon transmission from the WPRC; and
the processor is further configured to determine a phase of the WPRC beacon transmission as received at the first WPTS.
19. The first WPTS of claim 18 , wherein the transceiver is further configured to receive from the second WPTS, via the one or more antennas, an indication of a phase of the WPRC beacon transmission as received at the second WPTS.
20. The first WPTS of claim 18 , wherein the transceiver is further configured to directionally transmit, via the at least some of the plurality of antennas, third wireless power transmissions to the WPRC in collaboration with the second WPTS based on a detected phase of a peak received wireless power at the WPRC.