Method, system and device for measuring channel state information

• US 10,333,605 B2
• Filed: 04/22/2015
• Issued: 06/25/2019
• Est. Priority Date: 04/23/2014
• Status: Active Grant

• Current Assignee: Datang Mobile Communications Equipment Company Limited (China Information Communication Technology Group Co. Ltd.)
• Original Assignee: China Academy of Telecom Technology (China Information Communication Technology Group Co. Ltd.)
• Inventors: Su, Xin, Li, Chuanjun
• Primary Examiner(s): Mian, Omer S
• Application Number:
  US15/303,657
• Publication Number:
  US 20170033856A1
• Time in Patent Office: 1,525 Days
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

The present disclosure relates to the field of wireless communication technology, in particular to a method, system and device for measuring CSI, so as to solve the problem in the related art where, on the premise that a Massive MIMO technology plays to its strengths, a CSI measurement and feedback mechanism on the basis of a downlink reference signal may lead to obvious time-frequency resource overhead. The method includes steps of: transmitting, by a network side device, a group of reference signals which have been beamformed to a User Equipment (UE), so as to enable the UE to measure the reference signals, each reference signal in the group of reference signals corresponding to a space in a sector; and determining, by the network side device, whether or not a beamforming mode for each reference signal is to be adjusted in accordance with feedback information from the UE. According to the present disclosure, it is able to, on the premise that the Massive MIMO technology plays to its strengths, reduce the time-frequency resource overhead caused by the measurement and feedback of the downlink reference signals.

Claims

1. A method for measuring Channel State Information (CSI), comprising:

transmitting, by a network side device, a group of reference signals which have been beamformed to a User Equipment (UE), so as to enable the UE to measure the reference signals, each reference signal in the group of reference signals corresponding to a space in a sector, wherein correspondence between the group of reference signals and sector spaces is of a form of a mufti-level tree structure;

determining, by the network side device, quality information corresponding to each reference signal in accordance with an identifier and quality information from the UE;

determining, by the network side device, whether or not a beamforming mode for each reference signal is to be adjusted in accordance with the quality information corresponding to each reference signal;

determining, by the network side device, each space in the spaces corresponding to the reference signals with the best quality information, in the case that the beamforming mode for each reference signal needs to be adjusted; and

adjusting, by the network side device, the beamforming mode for the reference signal corresponding to each space, taking the reference signals with the best quality information as a group of reference signals, and transmitting the group of reference signals which have been beamformed to the UE,

wherein the network side device determines that a channel for transmitting reference signals to the UE is instable and the beamforming mode needs to be adjusted, in the case that changing speed of the channel exceeds a predetermined value, and otherwise, determines that the beamforming mode does not need to be adjusted.

2. The method according to claim 1, wherein the reference signals in the sector correspond to different identifiers.

3. The method according to claim 1, wherein each reference signal is a Channel State Information-Reference Signal (CSI-RS).

4. The method according to claim 3, wherein the reference signals in the sector correspond to different CSI-RS configurations and/or different CSI-RS ports;

wherein a group of CSI-RSs comprises parts of the CSI-RSs broadcast by the network side device, and the CSI-RSs transmitted to different UEs are partially or completely identical.

5. The method according to claim 1, wherein prior to the step of transmitting, by the network side device, the group of reference signals which have been beamformed to the UE, the method further comprises:

determining, by the network side device, different reference signals in accordance with one or more of time domain, frequency domain and code domain, wherein the different reference signals are orthogonal to each other.

6. A network side device for measuring Channel State Information (CSI), comprising a processor and a memory, wherein the memory is configured to store therein programs and data for an operation of the processor , and the processor is configured to read programs stored in the memory, so as to:

transmit a group of reference signals which have been beamformed to a User Equipment (UE), so as to enable the UE to measure the reference signals, each reference signal in the group of reference signals corresponding to a space in a sector, wherein correspondence between the group of reference signals and sector spaces is of a form of a multi-level tree structure;

determine quality information corresponding to each reference signal in accordance with an identifier and quality information from the UE;

determine whether or not a beamforming mode for each reference signal is to be adjusted in accordance with the quality information corresponding to each reference signal;

determine each space in the spaces corresponding to the reference signals with the best quality information, in the case that the beamforming mode for each reference signal needs to be adjusted; and

adjust the beamforming mode for the reference signal corresponding to each space, taking the reference signals with the best quality information as a group of reference signals, and transmitting the group of reference signals which have been beamformed to the UE,

wherein the network side device determines that a channel for transmitting reference signals to the UE is instable and the beamforming mode needs to be adjusted, in the case that changing speed of the channel exceeds a predetermined value, and otherwise, determines that the beamforming mode does not need to be adjusted.

7. The network side device according to claim 6, wherein the reference signals in the sector correspond to different identifiers.

8. The network side device according to claim 6, wherein each reference signal is a Channel State Information-Reference Signal (CSI-RS).

9. The network side device according to claim 8, wherein the reference signals in the sector correspond to different CSI-RS configurations and/or different CSI-RS ports, wherein a group of CSI-RSs comprises parts of the CSI-RSs broadcast by the network side device, and the CSI-RSs transmitted to different UEs are partially or completely identical.

10. The network side device according to claim 6, wherein the network side device is further configured to determine different reference signals in accordance with one or more of time domain, frequency domain and code domain, wherein the different reference signals are orthogonal to each other.