Angle of arrival estimation using a single receive chain

1. A circuit, comprising:

a memory storing instructions;

a receive chain; and

a processor coupled to the memory and to the receive chain, the processor configured to execute the instructions to:

receive, via the receive chain using a first antenna, a first portion of a preamble of a wireless transmission;

receive, via the receive chain using a second antenna, a second portion of the preamble of the wireless transmission; and

determine an angle of arrival of the wireless transmission based on the first portion and the second portion of the preamble of the wireless transmission.

2. The circuit of claim 1 , wherein the processor is further configured to execute the instructions to:

save the first portion of the preamble of the wireless transmission to the memory.

3. The circuit of claim 2 , wherein determining the angle of arrival of the wireless transmission is based on the saved first portion and the received second portion of the preamble of the wireless transmission.

4. The circuit of claim 1 , wherein the processor is further configured to execute the instructions to:

receive, via the receive chain, a remaining portion of the wireless transmission; and

decode the remaining portion of the wireless transmission.

5. The circuit of claim 4 , wherein the remaining portion of the wireless transmission is received using the first antenna.

6. The circuit of claim 1 , wherein the angle of arrival of the wireless transmission is based on a phase shift between the first portion and the second portion of the preamble of the wireless transmission.

7. The circuit of claim 1 , wherein the processor is further configured to execute the instructions to:

determine when the second portion of the preamble is expected to be received; and

switch from receiving the preamble using the first antenna to receiving the preamble using the second antenna based on when the second portion of the preamble is expected to be received.

8. The circuit of claim 1 , wherein the processor is further configured to execute the instructions to output the angle of arrival.

9. The circuit of claim 7 , wherein determining when the second portion of the preamble is expected to be received is based on an amount of time to switch to the second antenna.

10. The circuit of claim 1 , wherein the circuit is included in a first wireless device, and the wireless transmission is intended for a second wireless device.

11. A method comprising:

receiving, with a first antenna, a first portion of preamble or a body of a wireless transmission;

determining when a second portion of the preamble or the body of the wireless transmission is expected to be received;

receiving, with a second antenna, the second portion of the preamble or the body of the wireless transmission; and

determining an angle of arrival of the wireless transmission based on the first portion and the second portion of the preamble or the body of the wireless transmission.

12. The method of claim 11 , further comprising saving the first portion of the preamble or the body of the wireless transmission to a memory.

13. The method of claim 12 , wherein determining the angle of arrival of the wireless transmission is based on the saved first portion and the received second portion of the preamble or the body of the wireless transmission.

14. The method of claim 11 , further comprising:

receiving a remaining portion of the wireless transmission; and

decoding the remaining portion of the wireless transmission.

15. The method of claim 14 , wherein the remaining portion of the wireless transmission is received using the first antenna.

16. The method of claim 11 , wherein the angle of arrival of the wireless transmission is based on a phase shift between the first portion and the second portion of the preamble or the body of the wireless transmission.

17. The method of claim 11 , wherein determining when the second portion of the preamble or the body of the wireless transmission is expected to be received is based on an amount of time to switch to the second antenna.

18. The method of claim 11 , further comprising outputting the angle of arrival.

19. The method of claim 11 , further comprising switching from receiving the preamble or the body using the first antenna to receiving the preamble or the body using the second antenna based on when the second portion of the preamble or the body is expected to be received.

20. The method of claim 11 , wherein the method is performed by a first wireless device, and the wireless transmission is intended for a second wireless device.

21. A wireless device, comprising:

a receive chain;

a first antenna coupled to the receive chain;

a second antenna coupled to the receive chain;

a memory storing instructions; and

a processor coupled to the memory and to the receive chain, the processor configured to execute the instructions to:

receive, via the receive chain using the first antenna, a first portion of a body of a wireless transmission;

receive, via the receive chain using the second antenna, a second portion of the body of the wireless transmission; and

determine an angle of arrival of the wireless transmission based on the first portion and the second portion of the body of the wireless transmission.

22. The wireless device of claim 21 , wherein the processor is further configured to execute the instructions to:

determine when the second portion of the body of the wireless transmission is expected to be received; and

switch from receiving the body using the first antenna to receiving the body using the second antenna based on when the second portion of the body is expected to be received.