Method and apparatus for channel estimation in a distributed multi-node system

• US 9,379,960 B2
• Filed: 09/07/2012
• Issued: 06/28/2016
• Est. Priority Date: 09/09/2011
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Ihm, Bin Chul, Kim, Ki Tae, Kim, Su Nam, Kang, Ji Won, Chun, Jin Young, Park, Sung Ho
• Primary Examiner(s): Patel, Parth
• Application Number:
  US14/343,669
• Publication Number:
  US 20140198683A1
• Time in Patent Office: 1,390 Days
• Field of Search: 370/252, 370/208, 370/311, 370/329, 370/331, 455/522, 455/452.2, 455/456.1, 455/456.6, 455/550.1, 375/260, 375/224
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

Disclosed are a method and an apparatus for channel estimation in a multi-node distributed system. A method for channel state estimation comprises the steps of: a terminal receiving channel state information reference signal (CSI-RS) set-up information; and the terminal calculating interference on the basis of the CSI-RS set-up information and then transmitting channel state information (CSI) based on the interference, wherein the CSI-RS set-up information may include at least one of an external interference measurement field and an internal interference measurement field. Accordingly, during the external interference and internal interference measurements, the node for use in the interference measurements may be controlled by a base station so that interference is accurately measured and feedback of accurate channel information is enabled.

Claims

1. A method of measuring a channel state in a multi-node distributed system, the method comprising:

receiving, by a user equipment (UE), Channel State Information-Reference Signal (CSI-RS) configuration information from a node, wherein the node is one of a plurality of nodes that make up a node set in the multi-node distributed system; and

determining, by the UE, internal interference and external interference; and

transmitting Channel State Information (CSI) based on the internal interference and the external interference to the node,

wherein the CSI-RS configuration information includes an internal interference measurement field and an external interference field,

wherein the internal interference field includes information related to at least one first node among the plurality of nodes,

wherein the at least one first node transmits a non-zero power CSI-RS to determine internal interference in the node set,

wherein the external interference field includes information related to a second node among the plurality of nodes,

wherein the second node transmits a zero power CSI-RS to determine external interference in the node set,

wherein the UE computes the external interference based on the zero-power CSI-RS and the internal interference based on the non-zero-power CSI-RS, and wherein the zero power CSI-RS is a CSI-RS in which an energy value of a resource element is 0.

2. The method of claim 1, wherein the internal interference is generated by the plurality of nodes, and wherein the external interference is generated by at least one node not among the plurality of nodes.

3. The method of claim 1, wherein the internal interference field includes a bitmap, wherein the bitmap indicates the at least one first node among the plurality of nodes.

4. The method of claim 1, further comprising:

receiving, by the UE, another CSI-RS configuration information from another node among the plurality of nodes; and

determining, by the UE, another internal interference and another external interference based on the another CSI-RS configuration information; and

transmitting CSI based on the another internal interference and the another external interference to the another node, wherein the another CSI-RS configuration information includes another internal interference measurement field and another external interference field, wherein the another internal interference field includes information related to at least one third node among the plurality of nodes, wherein the at least one third node transmits a non-zero power CSI-RS to determine the another internal interference, wherein the external interference field includes information related to an a forth node among the plurality of nodes, and wherein the fourth node transmits a zero power CSI-RS to determine the another external interference.

5. A user equipment (UE) configured to measure a channel state in a multi-node distributed system, the UE comprising:

a radio frequency (RF) unit configured to transmit or receive a radio signal; and

a processor operatively connected to the RF unit and configured to;

receive Channel State Information-Reference Signal (CSI-RS) configuration information from a node, wherein the node is one of a plurality of nodes that make up a node set in the multi-node distributed system,

determine internal interference and external interference, and

transmit Channel State Information (CSI) based on the internal interference and the external interference to the node,

wherein the CSI-RS configuration information includes an internal interference measurement field and an external interference field,

wherein the internal interference field includes information related to at least one first node among the plurality of nodes,

wherein the at least one first node transmits a non-zero power CSI-RS to determine internal interference in the node set,

wherein the external interference field includes information related to a second node among the plurality of nodes,

wherein the second node transmits a zero power CSI-RS to determine external interference included in the node set,

wherein the UE computes the external interference based on the zero-power CSI-RS and the internal interference based on the non-zero-power CSI-RS, and wherein the zero power CSI-RS is a CSI-RS in which an energy value of a resource element is 0.

6. The UE of claim 5, wherein the internal interference is generated by the plurality of nodes, and wherein the external interference is generated by at least one node not among the plurality of nodes.

7. The UE of claim 5, wherein the internal interference field includes a bitmap, wherein the bitmap indicates the at least one first node among the plurality of nodes.

8. The UE of claim 5, wherein the processor is configured to:

receive another CSI-RS configuration information from another node included in the node set; and

determine another internal interference and another external interference based on the another CSI-RS configuration information, and transmit another CSI based on the another internal interference and the another external interference to the another node, wherein the another CSI-RS configuration information includes another internal interference measurement field and another external interference field, wherein the another internal interference field includes information related to at least one third node among the plurality of nodes, wherein the at least one third node transmits a non-zero power CSI-RS to determine the another internal interference, wherein the external interference field includes information related to an a forth node among the plurality of nodes, and wherein the fourth node transmits a zero power CSI-RS to determine the another external interference.