Method and apparatus for transmitting reference signal, method and apparatus for measuring and reporting channel state information, and method for configuring the same

Patent metadata

Field	Value
Publication number	US-2016142189-A1
Application number	US-201514935290-A
Country	US
Kind code	A1
Filing date	Nov 6, 2015
Priority date	Nov 7, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

A method in which a base station transmits a CSI (channel state information)-RS (reference signal) in a MIMO (multiple input multiple output) antenna system is provided. The base station periodically transmits a CSI-RS for first CSI to a terminal. The base station requests the terminal to transmit second CSI in a first subframe. When a CSI-RS occasion is configured, the base station transmits a CSI-RS for the second CSI to the terminal for a duration of the CSI-RS occasion from a second subframe or to the second subframe, which is a subframe after a first offset configured for CSI-RS transmission from the first subframe.

First claim

What is claimed is:

1 . A method in which a base station transmits a CSI (channel state information)-RS (reference signal) in a MIMO (multiple input multiple output) antenna system, the method comprising:
periodically transmitting a CSI-RS for first CSI to a terminal; requesting the terminal to transmit second CSI in a first subframe; and when a CSI-RS occasion is configured, transmitting a CSI-RS for the second CSI to the terminal for a duration of the CSI-RS occasion from a second subframe or to the second subframe, which is a subframe after a first offset configured for CSI-RS transmission from the first subframe.

2 . The method of claim 1 , wherein
the first CSI is CSI for one of a horizontal domain and a vertical domain, and the second CSI is CSI for the other one, and the requesting of the terminal to transmit the second CSI includes, when it is determined that at least one of update for the second CSI and feedback for the second CSI is necessary, requesting the terminal to transmit the second CSI.

3 . The method of claim 1 , wherein
the requesting of the terminal to transmit the CSI-RS for the second CSI includes: receiving a transmission request of the CSI-RS for the second CSI from the terminal in a third subframe; and requesting the terminal to transmit the second CSI in the first subframe that is a subframe after a second offset configured for CSI-RS transmission from the third subframe.

4 . The method of claim 3 , wherein
the receiving of the transmission request of the CSI-RS for the second CSI includes: receiving the transmission request of the CSI-RS for the second CSI from the terminal through at least one of a PUCCH (physical uplink control channel) and a MAC (medium access control) CE (control element).

5 . The method of claim 3 , wherein
the transmission request of the CSI-RS for the second CSI is transmitted from the terminal when a value of at least one of RSRP (reference signal received power), an RSSI (received signal strength indicator), RSRQ (reference signal received quality), and a CQI (channel quality indicator) or a variation degree of the value exceeds a threshold value.

6 . The method of claim 1 , wherein
the transmitting of the CSI-RS for the second CSI includes configuring a CSI-RS transmission resource for the second CSI such that the CSI-RS for the second CSI is not transmitted in a subframe in which the CSI-RS for the first CSI is transmitted or the CSI-RS transmission resource for the second CSI does not overlap with a CSI-RS transmission resource for the first CSI.

7 . The method of claim 1 , further comprising
configuring interconnection information between a periodic CSI report of the terminal and a aperiodic CSI report of the terminal in the terminal through signaling between the base station and the terminal, wherein CSI measurement for the aperiodic CSI report of the terminal is performed by the terminal configured with interconnection information, based on CSI measurement for the periodic CSI report of the terminal.

8 . A method in which a base station configures a terminal with measurement and report of CSI (channel state information) in a MIMO (multiple input multiple output) antenna system, the method comprising:
grouping a plurality of CSI-RS antenna ports and generating a plurality of CSI-RS antenna port groups; when a CSI report on a first CSI-RS antenna port group among the plurality of CSI-RS antenna port groups is to be requested to the terminal, including information indicating the first CSI-RS antenna port group in a CSI request field of a DL (downlink) DCI (downlink control information) format; and requesting a aperiodic CSI report from the terminal by using the CSI request field of the DCI.

9 . The method of claim 8 , further comprising,
when a CSI report on at least one domain of a horizontal domain and a vertical domain is to be requested to the terminal, including information corresponding to the at least one domain in the CSI request field of the DL DCI format.

10 . The method of claim 8 , further comprising:
when the terminal is made to measure second domain CSI among first domain CSI and the second domain CSI on condition of the first domain CSI, configuring a first CSI process for the first domain CSI as a reference CSI process among the first CSI process and a second CSI process for the second domain CSI; and informing the terminal of a process identifier indicating the first CSI process as information of the reference CSI process, wherein the first domain CSI is one of horizontal domain CSI and vertical domain CSI, and the second domain CSI is the other one of the horizontal domain CSI and the vertical domain CSI.

11 . The method of claim 10 , wherein
the configuring of the first CSI process as the reference CSI process includes: configuring the reference CSI process for one first CSI measurement subframe set in the terminal; and configuring the second CSI process for a plurality of second CSI measurement subframe sets in the terminal, wherein the second domain CSI for the plurality of second CSI measurement subframe sets is measured by the terminal on condition of the first domain CSI for the first measurement subframe set, which is measured through the reference CSI process.

12 . The method of claim 10 , wherein
the configuring of the first CSI process as the reference CSI process includes: configuring the reference CSI process for a plurality of CSI measurement subframe sets and the second CSI process for the plurality of CSI measurement subframe sets in the terminal, wherein the second domain CSI process for each of the plurality of CSI measurement subframe sets is measured by the terminal on condition of the first domain CSI for each of the plurality of CSI measurement subframe sets, which is measured through the reference CSI process.

13 . A method in which a base station configures a terminal with a CSI (channel state information) process in a MIMO (multiple input multiple output) antenna system, the method comprising:
when a plurality of CSI-RS (reference signal) antenna ports are operated in a first CSI-RS mode to have the same beam width and direction, including a plurality of first identifiers indicating a plurality of CSI-RS resource configurations and a second identifier indicating one CSI-IM (interference measurement) resource configuration in one piece of first CSI process configuration information; configuring the first CSI process configuration information in the terminal; and receiving CSI measured according to the first CSI process configuration information from the terminal.

14 . The method of claim 13 , wherein
numbers of a plurality of CSI-RS antenna ports included in a plurality of CSI-RS resources corresponding to the plurality of first identifiers are provided by the terminal according to an order of the plurality of first identifiers that are included in the first CSI process configuration information or values of the plurality of first identifiers.

15 . The method of claim 13 , further comprising:
when all or some of the plurality of CSI-RS antenna ports are operated in a second CSI-RS mode to have different beam directions, including a plurality of third identifiers indicating a plurality of CSI-RS resource configurations and a plurality of fourth identifiers indicating a plurality of CSI-IM resource configurations in one piece of second CSI process configuration information; configuring the second CSI process configuration information in the terminal; and receiving CSI measured according to the second CSI process configuration information

Assignees

• Korea Electronics Telecomm

Inventors

• Shin Wooram
• Kim Cheulsoon
• Moon Sung-Hyun
• Ko Young Jo

Classifications

• H04L25/0224

  using sounding signals · CPC title

• H04L5/0051

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

• H04B7/0626 Primary

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

• H04L5/0048 Primary

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04W72/046

  the resource being in the space domain, e.g. beams · CPC title