Method and device(s) for supporting calibration of a multi-antenna array comprised in an antenna device operative with a wireless communication network
Method and one or more first devices for supporting calibration of a multi-antenna array comprised in a first antenna device operative with a wireless communication network. The first device(s) provide phase correcting information, to be used in calibration of the multi-antenna array, based on covariances corresponding to recurrent displacement vectors of the multi-antenna array. Said covariances being based on channel estimates estimated from certain radio signals received after transmission over radio propagation channels between said multi-antenna array of the first antenna device and one or more second antenna devices operative with the wireless communication network.
1. A method, performed by one or more first devices, for supporting calibration of a multi-antenna array comprised in a first antenna device operative with a wireless communication network, wherein the method comprises:
providing phase correcting information, to be used in calibration of the multi-antenna array, based on covariances corresponding to recurrent displacement vectors of the multi-antenna array and wherein said covariances are based on channel estimates estimated from certain radio signals received after transmission over radio propagation channels between said multi-antenna array of the first antenna device and one or more second antenna devices operative with the wireless communication network.
2. A device for supporting calibration of a multi-antenna array, the device comprising a first antenna, wherein the multi-antenna array is comprised within the first antenna, wherein the device is configured to be operative with a wireless communication network, wherein the device is configured to:
provide phase correcting information, to be used in calibration of the multi-antenna array, based on covariances corresponding to recurrent displacement vectors of the multi-antenna array and wherein said covariances are based on channel estimates estimated from certain radio signals received after transmission over radio propagation channels between said multi-antenna array of the first antenna and one or more second antennas operative with the wireless communication network.
3. The device as claimed in claim 2 , wherein the provision of the phase correcting information is based on computation of elements of a diagonal matrix, “C”, according to a predetermined algorithm that operates on said covariances, wherein said diagonal matrix, “C”, relates to said channel estimates, “ĥ”, according to:
ĥ=Ch+s,
where “h” corresponds to the actual radio propagation channels being estimated and “s” corresponds to noise and estimation errors.
4. The device as claimed in claim 2 , wherein the device is further configured to:
calibrate the multi-antenna array based on the provided phase correcting information.
5. The device as claimed in claim 2 , wherein the first antenna corresponds to a radio network node comprised in the wireless communication network and said one or more second antennas correspond to one or more wireless communication devices configured to be served by the wireless communication network and the radio network node.
6. The device as claimed in claim 2 , wherein the first antenna corresponds to a wireless communication device configured to be served by the wireless communication network and said one or more second antennas correspond to a radio network node comprised in the wireless communication network and configured to serve the wireless communication device.
7. The device as claimed in claim 2 , wherein said certain radio signals correspond to predefined reference signals of the wireless communication network, and/or to data transmission signals, to or from, one or more wireless communication devices being served by the wireless communication network.
8. The device as claimed in claim 2 , wherein the device is further configured to:
obtain first information identifying said recurrent displacement vectors of the multi-antenna array;
obtain said channel estimates, and
obtain said covariances with said covariance matrix entries at least corresponding to said subset and based on said obtained channel estimates.
9. The device as claimed in claim 2 , wherein said certain radio signals are transmitted by said one or more second antennas and received by the first antenna, wherein said channel estimates are based on measurements by the first antenna on said received certain radio signals.
10. The device as claimed in claim 2 , wherein said certain radio signals are transmitted by said first antenna and received by one or more of said second antennas, wherein said channel estimates are based on measurements by said one or more second antennas on said received certain radio signals, wherein the device is further configured to:
receive, from one or more second devices, second information based on at least said channel estimates,
and wherein said phase corrections are provided based on said received second information.
11. The device as claimed in claim 10 , wherein the device is further configured to:
transmit, to said one or more second antennas, one or more messages, at least some requesting said one or more second devices to provide said second information,
and wherein said second information is received in response to transmission of said one or more messages.
12. The device as claimed in claim 11 , wherein said one or more messages comprises information identifying said certain radio signals and/or identifying which signals thereof are transmitted by which antenna element of the multi-antenna array.
13. The device as claimed in claim 10 , wherein said received second information comprises said channel estimates.
14. The device as claimed in claim 10 , wherein said received second information comprises covariances at least corresponding to said recurrent displacement vectors.
15. The device as claimed in claim 10 , wherein said received second information comprises at least part of said phase correcting information.
16. The device as claimed in claim 10 , wherein the device is further configured to:
transmit, to said one or more second devices, one or more messages comprising information regarding the multi-antenna array for supporting said one or more second devices to determine said covariances, and/or to provide said phase correcting information.
17. The device as claimed claim 2 , wherein each of said covariances is based on a combination of channel estimates relating to that covariance, wherein channel estimates of the combination pertain to different estimation occasions, and/or to channel estimation relating to different second antennas.
18. The device as claimed in claim 17 , wherein the combination of channel estimates relating to different second antennas is based on weighting the channel estimates so that second antennas experiencing better signal to noise ratio or associated with less angular spread in the channel are given a higher weighting.
19. A non-transitory computer-readable medium comprising instructions that when executed by one or more processors cause a device to:
provide phase correcting information, to be used in calibration of a multi-antenna array comprised in a first antenna, based on covariances corresponding to recurrent displacement vectors of the multi-antenna array and wherein said covariances are based on channel estimates estimated from certain radio signals received after transmission over radio propagation channels between said multi-antenna array of the first antenna and one or more second antennas operative with the wireless communication network.