Interference-aware beamforming
Aspects of the disclosure relate to an interference-aware beamforming environment in which an AP controller can determine one or more beams of one or more APs to serve various STAs. For example, an AP can request that STA(s) provide one or more uplink pilot signals during different time slots. The AP can receive the uplink pilot signal(s) and determine, for each STA, the uplink beam quality of each transmit beam-receive beam pair over which an uplink pilot signal was received from the respective STA. The AP can use reciprocity to determine, for each STA, the downlink beam quality for various transmit beam-receive beam pairs. The AP can use the determined downlink beam quality to identify the best beam with which to serve various STAs. An AP controller can determine which downlink beam(s) an AP should use to serve a STA based on the downlink beams originally selected by the APs.
1. An access point comprising:
a network communication device; and
a processor in communication with the network communication device, wherein computer-executable instructions, when executed by the processor, cause the access point to:
request an uplink pilot signal from a first station;
obtain a first uplink pilot signal and a second uplink pilot signal transmitted by the first station;
determine a candidate set of downlink beams to serve the first station using data derived from the first uplink pilot signal and the second uplink pilot signal;
transmit the determined candidate set of downlink beams to an access point controller;
obtain a selected set of downlink beams from the access point controller; and
determine a transmission rate for the first station and the selected set of downlink beams.
2. The access point of claim 1 , wherein the computer-executable instructions, when executed, further cause the access point to:
identify a first channel quality of a first receive beam over which the first uplink pilot signal is received;
identify a second channel quality of a second receive beam over which the second uplink pilot signal is received;
determine that the second channel quality of the second receive beam is higher than the first channel quality of the first receive beam; and
select a transmit beam corresponding to the second receive beam as one candidate in the determined candidate set of downlink beams.
3. The access point of claim 2 , wherein the computer-executable instructions, when executed, further cause the access point to obtain an instruction from the access point controller to transmit downlink communications to the first station using the selected transmit beam.
4. The access point of claim 1 , wherein the computer-executable instructions, when executed, further cause the access point to request channel quality feedback from the first station.
5. The access point of claim 4 , wherein the computer-executable instructions, when executed, further cause the access point to transmit a downlink pilot signal to the first station.
6. The access point of claim 4 , wherein the computer-executable instructions, when executed, further cause the access point to obtain the channel quality feedback from the first station.
7. The access point of claim 4 , where the channel quality feedback from the first station is comprised within an acknowledgement message.
8. The access point of claim 1 , wherein the transmission rate comprises a modulation and coding scheme.
9. The access point of claim 1 , wherein the selected set of downlink beams is based on the determined candidate set of downlink beams and a packet priority of the first station.
10. A computer-implemented method comprising:
requesting, by an access point, an uplink pilot signal from a first station;
receiving a first uplink pilot signal and a second uplink pilot signal transmitted by the first station;
determining a candidate set of downlink beams to serve the first station using data derived from the first uplink pilot signal and the second uplink pilot signal;
transmitting the determined candidate set of downlink beams to an access point controller;
receiving a selected set of downlink beams from the access point controller; and
determining a transmission rate for the first station and the selected set of downlink beams.
11. The computer-implemented method of claim 10 , wherein determining a candidate set of downlink beams further comprises:
identifying a first channel quality of a first receive beam over which the first uplink pilot signal is received;
identifying a second channel quality of a second receive beam over which the second uplink pilot signal is received;
determining that the second channel quality of the second receive beam is higher than the first channel quality of the first receive beam; and
selecting a transmit beam corresponding to the second receive beam as one candidate in the determined candidate set of downlink beams.
12. The computer-implemented method of claim 11 , further comprising receiving an instruction from the access point controller to transmit downlink communications to the first station using the selected transmit beam.
13. The computer-implemented method of claim 10 , further comprising requesting channel quality feedback from the first station.
14. The computer-implemented method of claim 13 , wherein requesting channel quality feedback from the first station further comprises transmitting a downlink pilot signal to the first station.
15. The computer-implemented method of claim 13 , further comprising obtaining the channel quality feedback from the first station.
16. The computer-implemented method of claim 13 , where the channel quality feedback from the first station is comprised within an acknowledgement message.
17. The computer-implemented method of claim 10 , wherein the transmission rate comprises a modulation and coding scheme.
18. The computer-implemented method of claim 10 , wherein the selected set of downlink beams is based on the determined candidate set of downlink beams and a packet priority of the first station.
19. Non-transitory, computer-readable storage media comprising computer-executable instructions, wherein the computer-executable instructions, when executed by an access point, cause the access point to:
request an uplink pilot signal from a first station;
obtain a first uplink pilot signal and a second uplink pilot signal transmitted by the first station;
determine a candidate set of downlink beams to serve the first station using data derived from the first uplink pilot signal and the second uplink pilot signal;
transmit the determined candidate set of downlink beams to an access point controller;
obtain a selected set of downlink beams from the access point controller; and
determine a transmission rate for the first station and the selected set of downlink beams.
20. The non-transitory, computer-readable storage media of claim 19 , wherein the computer-executable instructions, when executed, further cause the access point to:
identify a first channel quality of a first receive beam over which the first uplink pilot signal is received;
identify a second channel quality of a second receive beam over which the second uplink pilot signal is received;
determine that the second channel quality of the second receive beam is higher than the first channel quality of the first receive beam; and
select a transmit beam corresponding to the second receive beam as one candidate in the determined candidate set of downlink beams.