Techniques for beamforming to mitigate multi-user leakage and interference

Patent metadata

Field	Value
Publication number	US-9252853-B2
Application number	US-201314128614-A
Country	US
Kind code	B2
Filing date	Sep 27, 2013
Priority date	Mar 29, 2013
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

Examples are disclosed for beamforming to mitigate multi-user leakage and interference. The examples include an evolved node B (eNB) receiving feedback from user equipment (UEs) to indicate strongest or highest channel gains for various beams included in a plurality of beam sets. A selection process or scheme may then be implemented to select individual beams for a UE that minimizes or reduces leakage caused by the UE's use of a given beam. Reducing leakage may reduce interference to other UEs using other beams. Other examples are described and claimed.

First claim

The invention claimed is:

1. At least one non-transitory machine readable medium comprising a plurality of instructions that, in response to being executed at user equipment (UE) capable of operating in compliance with one or more 3 rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) standards including LTE-Advanced (LTE-A), cause the UE to:
receive a plurality of reference symbols from an evolved node B (eNB) via separate beams, each beam associated with one of a plurality of beam sets;
select a beam from each beam set according to a defined parameter;
report the selected beams to the eNB;
receive precoding weights for a given beam of the reported beams from the eNB, the given beam selected from among the plurality of beams based on the given beam causing no interference to other beams from among the plurality of beams selected for other UEs that is above a given interference threshold; and
receive data from the given beam using the precoding weights.

2. The at least one non-transitory machine readable medium of claim 1 , comprising instructions that, in response to being executed at the UE, cause the UE to select the beam from each beam set based on the defined parameter comprising a highest channel gain.

3. The at least one non-transitory machine readable medium of claim 1 , comprising instructions that, in response to being executed at the UE, cause the UE to report the selected beam to the eNB via transmission of a channel state information (CSI) report.

4. The at least one non-transitory machine readable medium of claim 1 , the plurality of antennas included in a multi-user, full-dimension, multiple-in and multiple-output, (FD-MIMO) system supported by the eNB.

5. An apparatus, comprising:
at least one memory; and
logic for user equipment (UE) capable of operating in compliance with one or more 3 rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) standards including LTE-Advanced (LTE-A), at least a portion of the logic in hardware coupled to the at least one memory, the logic to:
receive a plurality of reference symbols transmitted from an evolved node B (eNB), each received reference symbol precoded by the eNB and transmitted through a plurality of antennas via separate beams, each beam associated with one of a plurality of beam sets;
determine which beam has highest channel gain for each beam set;
report information to the eNB to indicate respective highest channel gain beams for each beam set;
receive data including precoding weights set based on a given beam selected by the eNB based on the reported highest channel gain beams, and;
use the precoding weights to receive data via the given beam.

6. The apparatus of claim 5 , the given beam selected from among the plurality of beams based on the given beam causing no interference to other beams from among the plurality of beams selected for other UEs that is above a given interference threshold.

7. The apparatus of claim 5 , the logic to report information to the eNB by causing transmission of a channel state information (CSI) report to the eNB.

8. The apparatus of claim 5 , the plurality of antennas included in a multi-user, full-dimension, multiple-in and multiple-output, (FD-MIMO) system supported by the eNB.

9. The apparatus of claim 5 , comprising a digital display coupled to the logic to present a user interface view.

10. An apparatus, comprising:
at least one memory; and
logic for an evolved Node B (eNB) capable of operating in compliance with one or more 3 rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) standards including LTE-Advanced (LTE-A), the eNB having a plurality of antennas, at least a portion of the logic in hardware coupled to the at least one memory, the logic to:
group a plurality of beams in beam sets, each beam arranged to be transmitted from the plurality of antennas;
generate reference symbols for each beam set;
activate each beam set by precoding each beam in each beam set using the reference symbols for each beam set;
cause the reference symbols in an activated beam set to be transmitted via the precoded beams;
receive feedback from a plurality of user equipment (UEs) that indicates which beam from each beam set has a highest channel gain as detected by each of the plurality of UEs;
select a number of UEs from among the plurality of UEs, the number of selected UEs to equal a total number of beam sets having the grouped beams;
select a beam from among the plurality of beams for a first selected UE based on the beam causing no interference to other beams from among the plurality of beams selected for other selected UEs that is above a given interference threshold; and
forward data to the first selected UE that includes precoding weights set based on the selected beam.

11. The apparatus of claim 10 , comprising the logic to:
create a gain table having three or more rows to indicate strongest to weakest channel gains reported by respective selected UEs indicated in each column of the gain table, the first row to indicate strongest channel gain; and
reject individual beams having a strongest channel gain for a given selected UE based on the strongest channel gain beam included in a second or third row of the gain table for any of the other selected UEs indicating interference above the given interference threshold.

12. The apparatus of claim 11 , the rejected strongest channel gain beam included in the second or third row of the gain table for any of the other selected UEs to indicate the rejected strongest channel gain beam causes signal leakage that interferes with strongest channel gain beams for the other selected UEs.

13. The apparatus of claim 10 , the logic to:
assign sequential index identifiers to each beam set; and
iteratively activate each beam set according to assigned sequential identifiers.

14. The apparatus of claim 10 , the plurality of antennas included in a multi-user, full-dimension, multiple-in and multiple-output, (FD-MIMO) system supported by the eNB.

15. The apparatus of claim 10 , the logic to activate each beam set over a given number of consecutive sub-frames, the given number based on a system design or at least one environmental parameter via which each beam is to be transmitted.

16. The apparatus of claim 10 , the feedback from the plurality of UEs received via separate channel state information (CSI) reports from the plurality of UEs.

17. The apparatus of claim 10 , comprising a digital display coupled to the logic to present a user interface view.

18. A computer-implemented method comprising:
grouping, at an evolved Node B (eNB) capable of operating in compliance with one or more 3 rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) standards including LTE-Advanced (LTE-A), a plurality of beams in beam sets, each beam arranged to be transmitted from a plurality of antennas;
generating reference symbols for each beam set;
activating each beam set by precoding each beam in each beam set using the reference symbols for each beam set;
causing the reference symbols in an activated beam set to be transmitted via the precoded beams;
receiving feedback from a plurality of user equipment (UEs) that indicates which beam from each beam set has a highest channel gain as detected by each of the plurality of UEs;
selecting a number of UEs from among the plurality of UEs, the number of selected UEs to equal a total number of beam sets having the grouped beams;
creating a gain table having three or more rows to indicate strongest to weakest channel gains rep

Assignees

• Intel Corp

Inventors

• Sajadieh Masoud
• Shirani-Mehr Hooman

Classifications

• H04L5/0007

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title

• H04W56/001

  Synchronization between nodes · CPC title

• H04N21/2402

  Monitoring of the downstream path of the transmission network, e.g. bandwidth available (traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876) · CPC title

• H04B7/0695

  using beam selection · CPC title

• H04L5/0051

  of dedicated pilots, i.e. pilots destined for a single user or terminal · CPC title