Method and apparatus for separable channel state feedback in a wireless communication system

Patent metadata

Field	Value
Publication number	US-9485661-B2
Application number	US-201313750783-A
Country	US
Kind code	B2
Filing date	Jan 25, 2013
Priority date	Oct 24, 2008
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

Systems and methodologies are described herein that facilitate the generation and use of separable, hierarchical channel state feedback in a wireless communication system. As described herein, in the event that multiple network nodes cooperate to conduct downlink transmissions to a network user, channel state feedback as reported by the network user can be separated into intra-node feedback relating to per-node channel conditions and inter-node feedback relating to relative phase and/or amplitude between channels corresponding to respective nodes. Further, a network user can select to report intra-node feedback and/or inter-node feedback based on network instructions, a cooperation strategy to be utilized by respective network nodes, or the like. As additionally described herein, respective codebooks on which inter-node and intra-node channel feedback is based can be configured to convey information relating to a partial channel description and/or to vary based on resource units (e.g., sub-bands, resource blocks, etc.) utilized for downlink communication.

First claim

What is claimed is:

1. A method, comprising:
analyzing parameters relating to both mobility of an associated user equipment (UE) unit and network conditions;
selecting a downlink coordination strategy to be utilized across network nodes for communication with the associated UE unit based on the analyzed parameters; and
instructing the associated UE unit to provide at least one of an intra-node channel state feedback or an inter-node channel state feedback to the network nodes based at least in part on the selected downlink coordination strategy.

2. The method of claim 1 , wherein:
the selecting comprises selecting cooperative transmit interference nulling as the downlink coordination strategy upon determining that analyzed mobility of the associated UE unit is substantially high or analyzed network conditions are substantially inadequate for joint transmission; and
the instructing comprises instructing the associated UE unit to provide the intra-node channel state feedback only.

3. The method of claim 1 , wherein:
the selecting comprises selecting joint transmission as the downlink coordination strategy upon determining that analyzed mobility of the associated UE unit is substantially low and analyzed network conditions are sufficient to support the joint transmission; and
the instructing comprises instructing the associated UE unit to provide the intra-node channel state feedback and the inter-node channel state feedback.

4. The method of claim 1 , wherein:
the method further comprises identifying a number of utilized transmit antennas; and
the instructing comprises instructing the associated UE unit to provide the inter-node channel state feedback only upon determining that a single transmit antenna is utilized.

5. The method of claim 1 , further comprising receiving the at least one of the intra-node channel state feedback and the inter-node channel state feedback from the associated UE unit, wherein the intra-node channel state feedback comprises one or more precoding indices corresponding to respective entries in one or more intra-node precoding codebooks, and the inter-node channel state feedback comprises one or more precoding indices corresponding to respective entries in one or more inter-node precoding codebooks, according to the instructing.

6. The method of claim 5 , wherein:
the method further comprises identifying a set of resource units to be utilized for communication to the associated UE unit; and
the instructing comprises instructing the associated UE unit to provide the at least one of the intra-node channel state feedback and the inter-node channel state feedback corresponding to entries in one or more associated precoding codebooks that correspond to the set of resource units to be utilized for communication to the associated UE unit.

7. The method of claim 6 , wherein the set of resource units comprises at least one of frequency sub-bands or resource blocks.

8. A wireless communications apparatus, comprising:
a memory that stores data relating to a network user and a backhaul link between the wireless communications apparatus and at least one cooperative network node; and
a processor configured to:
analyze respective parameters relating to both at least one of mobility of the network user and network conditions of the backhaul link,
select a downlink coordination strategy to be utilized across network nodes for communication with the network user based on the respective parameters, and
instruct the network user to provide at least one of an intra-node channel state feedback or an inter-node channel state feedback based at least in part on the selected downlink coordination strategy.

9. The wireless communications apparatus of claim 8 , wherein the processor is further configured to select cooperative beamforming as the downlink coordination strategy upon determining that mobility of the network user is substantially high or the network conditions are substantially inadequate for joint transmission and to instruct the network user to provide the intra-node channel state feedback.

10. The wireless communications apparatus of claim 8 , wherein the processor is further configured to select joint transmission as the downlink coordination strategy upon determining that mobility of the network user is substantially low and the network conditions are sufficient to support the joint transmission and to instruct the network user to provide both the intra-node channel state feedback and the inter-node channel state feedback.

11. The wireless communications apparatus of claim 8 , wherein the processor is further configured to identify a number of transmit antennas utilized by the wireless communications apparatus and to instruct the network user to provide the inter-node channel state feedback upon determining that a single transmit antenna is utilized by the wireless communications apparatus.

12. An apparatus, comprising:
means for selecting, based at least in part on an analysis of mobility of with a user equipment (UE) unit, network conditions, and a number of associated transmit antennas, a coordination strategy to be utilized across network nodes for downlink communication with the UE unit; and
means for requesting one or more of an intra-node channel state feedback or an inter-node channel state feedback from the UE unit based at least in part on the selected coordination strategy.

13. The apparatus of claim 12 , wherein:
the means for selecting comprises means for selecting cooperative transmit interference nulling upon determining that mobility of the UE unit is substantially high or that the network conditions are substantially inadequate for joint transmission; and
the means for requesting comprises means for requesting the intra-node channel state feedback from the UE unit.

14. The apparatus of claim 12 , wherein:
the means for selecting comprises means for selecting inter-site packet sharing upon determining that mobility of the UE unit is substantially low and that the network conditions are substantially sufficient for supporting packet sharing; and
the means for requesting comprises means for requesting the intra-node channel state feedback and the inter-node channel state feedback from the UE unit.

15. The apparatus of claim 12 , wherein the means for requesting comprises means for requesting the inter-node channel state feedback from the UE unit upon determining that the number of associated transmit antennas is a single transmit antenna.

16. A non-transitory computer-readable medium storing instruction, the instructions comprising:
one or more instructions which, when executed by a processor, cause the processor to:
select, based at least in part on an analysis of mobility of with a user equipment (UE) unit, network conditions, and a number of associated transmit antennas, a coordination strategy to be utilized across network nodes for downlink communication with the UE unit; and

request one or more of an intra-node channel state feedback or an inter-node channel state feedback from the UE unit based at least in part on the selected coordination strategy.

17. The non-transitory computer-readable medium of claim 16 , wherein:
one or more instructions to select the coordination strategy comprise:
one or more instructions to select cooperative transmit interference nulling upon determining that mobility of the UE unit is substantially high or that the network conditions are substantially inadequate for joint transmission; and

one or more instructions to request the one or more of the intra-node channel state feedback

Assignees

• Qualcomm Inc

Inventors

• Gorokhov Alexei Y

Classifications

• B25B23/0021 Primary

  Prolongations interposed between handle and tool · CPC title

• H04B7/0478

  Special codebook structures directed to feedback optimisation · CPC title

• H04B7/0417

  Feedback systems · CPC title

• H04B7/024

  Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems · CPC title

• H04B7/0626

  Channel coefficients, e.g. channel state information [CSI] · CPC title