Online calibration with phase or signal strength measurements

1. An apparatus for wireless communication at a first wireless device, comprising:

a memory; and

at least one processor coupled to the memory and, based at least in part on information stored in the memory, the at least one processor is configured to:

negotiate a configuration of a radio frequency (RF) chain calibration process with a second wireless device, the configuration of the RF chain calibration process including a number of calibration rounds; and

exchange, in each calibration round in the number of calibration rounds, at least one reference signal (RS) and at least one feedback message with the second wireless device based on the configuration of the RF chain calibration process.

2. The apparatus of claim 1 , the at least one processor being further configured to:

identify one or more calibration adjustment parameters for the first wireless device based on the RF chain calibration process; and

communicate with another wireless device based on the one or more calibration adjustment parameters.

3. The apparatus of claim 2 , the at least one processor being further configured to:

identify one or more relationships between a plurality of first antenna elements associated with the first wireless device based on the at least one RS and the at least one feedback message, wherein the one or more calibration adjustment parameters for the first wireless device are based on the one or more relationships between the plurality of first antenna elements associated with the first wireless device.

4. The apparatus of claim 2 , wherein the one or more calibration adjustment parameters are associated with one or more of an amplifier, a mixer, a coupler, a filter, a digital-to-analog converter (DAC), or an analog-to-digital converter (ADC).

5. The apparatus of claim 1 , wherein to exchange, in each calibration round in the number of calibration rounds, the at least one RS and the at least one feedback message with the second wireless device, the at least one processor is further configured to:

transmit, in each calibration round in the number of calibration rounds, a first RS to the second wireless device;

receive, in each calibration round in the number of calibration rounds, a second RS from the second wireless device, the first RS and the second RS being associated with a same set of beamforming weights at the first wireless device and the second wireless device; and

transmit, in each calibration round in the number of calibration rounds, a feedback message to the second wireless device based on the second RS.

6. The apparatus of claim 1 , the at least one processor being further configured to:

exchange device capability/status information associated with at least one of the first wireless device or the second wireless device with the second wireless device, wherein the configuration of the RF chain calibration process is based on the device capability/status information associated with the at least one of the first wireless device or the second wireless device.

7. The apparatus of claim 6 , wherein the device capability/status information associated with the at least one of the first wireless device or the second wireless device comprises one or more of a number of antenna elements, a signal measurement capability, or a calibration status.

8. The apparatus of claim 7 , wherein the first wireless device is capable of signal strength measurement, and the second wireless device is capable of signal strength measurement.

9. The apparatus of claim 7 , wherein the first wireless device is or is not capable of phase measurement, the first wireless device is calibrated or uncalibrated, the second wireless device is or is not capable of phase measurement, and the second wireless device is calibrated or uncalibrated.

10. The apparatus of claim 6 , wherein the number of calibration rounds is based on the device capability/status information associated with the at least one of the first wireless device or the second wireless device.

11. The apparatus of claim 1 , wherein a link between the first wireless device and the second wireless device is an access link or a sidelink.

12. The apparatus of claim 1 , further comprising a transceiver coupled to the at least one processor.

13. A method of wireless communication at a first wireless device, comprising:

negotiating a configuration of a radio frequency (RF) chain calibration process with a second wireless device, the configuration of the RF chain calibration process including a number of calibration rounds; and

exchanging, in each calibration round in the number of calibration rounds, at least one reference signal (RS) and at least one feedback message with the second wireless device based on the configuration of the RF chain calibration process.

14. The method of claim 13 , further comprising:

identifying one or more calibration adjustment parameters for the first wireless device based on the RF chain calibration process; and

communicating with another wireless device based on the one or more calibration adjustment parameters.

15. The method of claim 14 , further comprising:

identifying one or more relationships between a plurality of first antenna elements associated with the first wireless device based on the at least one RS and the at least one feedback message, wherein the one or more calibration adjustment parameters for the first wireless device are based on the one or more relationships between the plurality of first antenna elements associated with the first wireless device.

16. An apparatus for wireless communication at a second wireless device, comprising:

a memory; and

at least one processor coupled to the memory and, based at least in part on information stored in the memory, the at least one processor is configured to:

negotiate a configuration of a radio frequency (RF) chain calibration process with a first wireless device, the configuration of the RF chain calibration process including a number of calibration rounds;

exchange, in each calibration round in the number of calibration rounds, at least one reference signal (RS) and at least one feedback message with the first wireless device;

identify one or more calibration adjustment parameters for the second wireless device based on the RF chain calibration process; and

communicate with another wireless device based on the one or more calibration adjustment parameters.

17. The apparatus of claim 16 , the at least one processor being further configured to:

identify one or more relationships between a plurality of second antenna elements associated with the second wireless device based on the at least one RS and the at least one feedback message, wherein the one or more calibration adjustment parameters for the second wireless device are based on the one or more relationships between the plurality of second antenna elements associated with the second wireless device.

18. The apparatus of claim 16 , wherein the one or more calibration adjustment parameters are associated with one or more of an amplifier, a mixer, a coupler, a filter, a digital-to-analog converter (DAC), or an analog-to-digital converter (ADC).

19. The apparatus of claim 16 , wherein to exchange, in each calibration round in the number of calibration rounds, the at least one RS and the at least one feedback message with the first wireless device, the at least one processor is further configured to:

receive, in each calibration round in the number of calibration rounds, a first RS from the first wireless device;

transmit, in each calibration round in the number of calibration rounds, a second RS to the first wireless device, the first RS and the second RS being associated with a same set of beamforming weights at the first wireless device and the second wireless device; and

receive, in each calibration round in the number of calibration rounds, a feedback message from the first wireless device based on the second RS,

wherein the one or more calibration adjustment parameters are identified for the second wireless device based on the first RS and the feedback message.

20. The apparatus of claim 16 , the at least one processor being further configured to:

exchange device capability/status information associated with at least one of the first wireless device or the second wireless device with the first wireless device, wherein the configuration of the RF chain calibration process is based on the device capability/status information associated with the at least one of the first wireless device or the second wireless device.

21. The apparatus of claim 20 , wherein the device capability/status information associated with the at least one of the first wireless device or the second wireless device comprises one or more of a number of antenna elements, a signal measurement capability, or a calibration status.

22. The apparatus of claim 21 , wherein the first wireless device is capable of signal strength measurement, and the second wireless device is capable of signal strength measurement.

23. The apparatus of claim 21 , wherein the first wireless device is or is not capable of phase measurement, the first wireless device is calibrated or uncalibrated, the second wireless device is or is not capable of phase measurement, and the second wireless device is calibrated or uncalibrated.

24. The apparatus of claim 20 , wherein the number of calibration rounds is based on the device capability/status information associated with the at least one of the first wireless device or the second wireless device.

25. The apparatus of claim 16 , wherein a link between the first wireless device and the second wireless device is an access link or a sidelink.

26. The apparatus of claim 16 , further comprising a transceiver coupled to the at least one processor.

27. A method of wireless communication at a second wireless device, comprising:

negotiating a configuration of a radio frequency (RF) chain calibration process with a first wireless device, the configuration of the RF chain calibration process including a number of calibration rounds;

exchanging, in each calibration round in the number of calibration rounds, at least one reference signal (RS) and at least one feedback message with the first wireless device;

identifying one or more calibration adjustment parameters for the second wireless device based on the RF chain calibration process; and

communicating with another wireless device based on the one or more calibration adjustment parameters.

28. The method of claim 27 , further comprising:

identifying one or more relationships between a plurality of second antenna elements associated with the second wireless device based on the at least one RS and the at least one feedback message, wherein the one or more calibration adjustment parameters for the second wireless device are based on the one or more relationships between the plurality of second antenna elements associated with the second wireless device.

29. The method of claim 27 , wherein the one or more calibration adjustment parameters are associated with one or more of an amplifier, a mixer, a coupler, a filter, a digital-to-analog converter (DAC), or an analog-to-digital converter (ADC).

30. The method of claim 27 , wherein the exchanging, in each calibration round in the number of calibration rounds, the at least one RS and the at least one feedback message with the first wireless device further comprises:

receiving, in each calibration round in the number of calibration rounds, a first RS from the first wireless device;

transmitting, in each calibration round in the number of calibration rounds, a second RS to the first wireless device, the first RS and the second RS being associated with a same set of beamforming weights at the first wireless device and the second wireless device; and

receiving, in each calibration round in the number of calibration rounds, a feedback message from the first wireless device based on the second RS,

wherein the one or more calibration adjustment parameters are identified for the second wireless device based on the first RS and the feedback message.