Methods and Apparatus For Device Scheduling

• US 20140204770A1
• Filed: 01/18/2013
• Published: 07/24/2014
• Est. Priority Date: 01/18/2013
• Status: Active Grant

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Mondal, Bishwarup, Visotsky, Eugene
• Granted Patent: US 9,042,255 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling

Abstract

Systems and techniques for crosstalk estimation. One or more user devices feed back preceding matrix indicator rank information to one or more base stations, which generated channel state information reference sources, at least one of which includes weightings based on the preceding matrix indicator rank information. One or more user devices estimates channel information based on active preceding matrix indicator information received by the base station from at least one user device. One or more user devices computes channel estimates for a desired transmission channel and one or more other potential transmission channels associated with other user devices and performs crosstalk estimation for the estimated channels. Crosstalk estimation information is fed back to a base station, which performs scheduling based at least in part on the crosstalk estimation from the one or more user devices.

Claims

1. An apparatus comprising:

at least one processor;

memory storing computer program code;

wherein the memory storing the computer program code is configured to, with the at least one processor, cause the apparatus to at least;

control a user device operating in a wireless communications network to monitor at least first and second channel state information reference signal resources, wherein at least one of the channel state information reference signal resources is weighted by a transmit weight chosen from an active precoding matrix indicator rank indicator set;

control the user device to compute channel estimation to estimate a first channel, and determine single user multiple-input multiple-output channel quality information, based on the first channel state information reference signal resource;

control the user device to perform channel estimation to estimate a second channel, wherein the second channel comprises at least one precoded downlink multiple-input multiple-output channel for which transmit weights chosen from the active precoding matrix indicator rank indicator set are used for precoding;

control the user device to compute crosstalk between a desired and a simultaneously scheduled transmission, on the estimated first and second channel, wherein crosstalk estimation is based at least in part on at least one interfering transmit weight used for channel state information reference signal precoding; and

control the user device to feed back the computed crosstalk to a base station.

2. The apparatus of claim 1, wherein estimation of the at least the second channel is based on a specified subset of channel state information reference signal ports in the second channel state information reference signal resource.

3. The apparatus of claim 1, wherein the active precoding matrix indicator rank indicator set used for precoding is a collection of transmit weights constructed by a base station based in part on the precoding matrix indicators and rank indicators fed back by one or more user devices that are currently active in the downlink,

4. The apparatus of claim 1, wherein a desired transmission is a transmission on a desired downlink multiple-input multiple-output channel computed based at least in part on the user device'"'"'s most recently fed back precoding matrix indicator index.

5. The apparatus of claim 1, wherein the computed crosstalk is fed back in the form of a quantized crosstalk to desired power ratio.

6. The apparatus of claim 1, wherein the computed crosstalk is fed back in the form of channel quality information.

7. An apparatus comprising:

at least one processor;

memory storing computer program code;

wherein the memory storing the computer program code is configured to, with the at least one processor, cause the apparatus to at least;

control a base station operating in a wireless communications network to generate at least first and second channel state information reference signal resources, wherein at least one of the channel state information reference signal resources is weighted by a transmit weight chosen from an active precoding matrix indicator rank indicator set; and

control the base station to perform pairwise scheduling of a first and a second user device for transmission, wherein selection of the first and the second user device is based at least in part on crosstalk estimation fed back by at least one user device, wherein the crosstalk estimation is computed based on an estimated first channel and an estimated a second channel, wherein the second channel comprises at least one precoded downlink multiple-input multiple-output channel for which transmit weights chosen from an active precoding matrix indicator rank indicator set are used for precoding.

8-13. -13. (canceled)

14. A method comprising:

controlling a user device operating in a wireless communications network to monitor at least first and second channel state information reference signal resources, wherein at least one of the channel state information reference signal resources is weighted based on an active precoding matrix indicator rank indicator set;

controlling the user device to compute channel estimation to estimate a first channel, and determine single user multiple-input multiple-output channel quality information, based on the first channel state information reference signal resource;

controlling the user device to perform crosstalk estimation to estimate a second channel, wherein the a second channel comprises at least one precoded downlink multiple-input multiple-output channel for which transmit weights in the active preceding matrix indicator rank indicator set are used for precoding;

controlling the user device to compute crosstalk between a desired and a simultaneously scheduled transmission, at least on the estimated first and at least the second channel, wherein crosstalk estimation is based at least in part on at least one interfering transmit weight used for channel state information reference signal precoding; and

controlling the user device to feed back the computed crosstalk to a base station.

15. The method of claim 14, wherein estimation of the at least the second channel is based on a specified subset of channel state information reference signal ports in the second channel state information reference signal resource.

16. The method of claim 14, wherein the active precoding matrix indicator rank indicator set used for precoding is a collection of transmit weights constructed by a base station based in part on the precoding matrix indicators and rank indicators fed back by one or more user devices that are currently active in the downlink.

17. The method of claim 14, wherein a desired transmission is a transmission on a desired precoded downlink multiple-input multiple-output channel computed based on the user device'"'"'s most recently fed back precoding matrix indicator index.

18. The method of claim 14, wherein the computed crosstalk is fed back in the form of a quantized crosstalk to desired power ratio.

19. The method of claim 14, wherein the computed crosstalk is fed back as part of channel quality information.

20. A method comprising;

controlling a base station operating in a wireless communications network to generate at least first and second channel state information reference signal resources, wherein at least one of the channel state information reference signal resources is weighted based on an active precoding matrix index rank indicator set; and

controlling the base station to perform pairwise scheduling of a first and a second user device for transmission, wherein selection of the first and the second user device is based at least in part on crosstalk estimation fed back by at least one user device, wherein the crosstalk estimation is computed based on at least an estimated first channel and an estimated a second channel, wherein the at least the second channel comprises at least one precoded downlink multiple-input multiple-output channel for which transmit weights in an active precoding matrix index rank indicator set are used for precoding. and wherein the transmit weights are transmit weights of a channel state information reference signal resource and based on an active precoding matrix indicator received by the base station from at least one user device.

21-26. -26. (canceled)