METHOD AND DEVICE FOR REPORTING CHANNEL STATE

• US 20130343216A1
• Filed: 11/30/2011
• Published: 12/26/2013
• Est. Priority Date: 12/02/2010
• Status: Active Grant

• Current Assignee: Datang Mobile Communications Equipment Company Limited (China Information Communication Technology Group Co. Ltd.)
• Original Assignee: Datang Mobile Communications Equipment Company Limited (China Information Communication Technology Group Co. Ltd.)
• Inventors: Su, Xin, Gao, Qiubin, Tamrakar, Rakesh, Shen, Zukang
• Granted Patent: US 9,363,700 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• 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 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports

Abstract

There is disclosed method for reporting channel state so as to report channel state based upon CSI-RS. The method includes: a UE detecting configuration information of Channel State Information-Reference Signal (CSI-RS), determining according to detection result the number of ports required to report channel state based upon CSI-RS, the UE determining CSI-RS based PMI feedback scheme to be adopted in preset corresponding relationship between the number of ports and feedback scheme upon determining that the eNB is to map data of Physical Downlink Shared Channel (PDSCH) onto P (number) CSI-RS ports for transmission in a codebook-based precoding scheme, wherein the codebook-based precoding scheme is a scheme as represented in the formula of

$\left[\begin{array}{c}{y}^{\left(0\right)}\\ ⋮\\ y^{\left(P-1\right)}\end{array}\right]=W·s,$

wherein W represents a codebook consisted of a precoding matrix, S is PDSCH data consisted of data layers whose quantity is equal to value of Rank Indication (RI) and

$\hspace{1em}\left[\begin{array}{c}{y}^{\left(0\right)}\\ ⋮\\ y^{\left(P-1\right)}\end{array}\right]$

represents a vector consisted of data on P (number) CSI-RS ports; and the UE calculating and reporting channel state information according to the determination result. The invention further discloses apparatus for performing the method.

Claims

1. A method for reporting channel state, comprising:

detecting, by a User Equipment (UE), configuration information of Channel State Information-Reference Signal (CSI-RS);

determining, by the UE, according to detection result, number of ports required to report channel state based upon the CSI-RS;

determining, by the UE, CSI-RS based Precoding Matrix Indicator (PMI) feedback scheme to be adopted by the UE according to the determined number of ports and preset corresponding relationship between the number of ports and feedback scheme, upon determining that the eNB is to map data of Physical Downlink Shared Channel (PDSCH) onto P (number) CSI-RS ports for transmission according to a codebook-based precoding scheme, wherein the codebook-based precoding scheme is a scheme as represented in the formula of

2. The method according to claim 1, wherein the preset corresponding relationship between the number of ports and feedback scheme comprises:

the number of ports being equal to 1 corresponds to non-PMI feedback scheme; and

the number of ports being larger than 1 corresponds to the CSI-RS based PMI feedback scheme.

3. The method according to claim 2, wherein when determined feedback scheme is the CSI-RS based PMI feedback scheme, the reported channel state information comprises CQI, PMI and RI.

4. The method according to claim 3, wherein when the determined feedback scheme is the CSI-RS based PMI feedback scheme, an operation of calculating and reporting, by the UE, channel state information according to the determination result comprises:

calculating and reporting, by the UE, the PMI for each report unit in the frequency domain according to determined mapping scheme;

calculating and reporting, by the UE, the RI for full bandwidth according to the determined mapping scheme; and

calculating and reporting, by the UE, the CQI according to the determined mapping scheme, the PMI and the RI.

5. The method according to claim 4, wherein an operation of calculating and reporting, by the UE, the CQI according to the CSI-RS based PMI feedback scheme and the calculated RI comprises:

calculating and reporting, by the UE, one CQI in each report unit in the frequency domain when the RI is equal to 1; and

calculating and reporting, by the UE, CQI respectively for two codewords in each report unit in the frequency domain when the RI is larger than 1.

6. The method according to claim 1, wherein the determining, by the UE, that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of

13. The method according to claim 2, wherein the determining, by the UE, that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of

14. The method according to claim 3, wherein the determining, by the UE, that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of

15. The method according to claim 4, wherein the determining, by the UE, that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of

16. The method according to claim 5, wherein the determining, by the UE, that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of

7. A user equipment, comprising:

a detection module configured to detect configuration information of Channel State Information-Reference Signal (CSI-RS);

a ports quantity module configured to determine, according to detection result, number of ports required to report channel state based upon CSI-RS;

a transmission mode module configured to determine CSI-RS based Precoding Matrix Indicator (PMI) feedback scheme to be adopted by the UE according to the determined number of ports and preset corresponding relationship between the number of ports and feedback scheme upon determining that the eNB is to map data of Physical Downlink Shared Channel (PDSCH) onto P (number) CSI-RS ports for transmission according to a codebook-based precoding scheme, wherein the codebook-based precoding scheme is a scheme as represented in the formula

8. The user equipment according to claim 7, wherein the preset corresponding relationship between the number of ports and feedback scheme comprises:

the number of ports being equal to 1 corresponding to non-PMI feedback scheme; and

the number of ports being larger than 1 corresponding to CSI-RS based PMI feedback scheme.

9. The user equipment according to claim 8, wherein when determined feedback scheme is CSI-RS based PMI feedback scheme, the reported channel state information comprises CQI, PMI and RI.

10. The user equipment according to claim 9, wherein when the determined feedback scheme is CSI-RS based PMI feedback scheme, the report module calculates and reports PMI for each report unit in the frequency domain according to determined mapping scheme, calculates and reports RI for full bandwidth according to the determined mapping scheme, and calculates and reports CQI according to the determined mapping scheme, the PMI and the RI.

11. The user equipment according to claim 10, wherein the report module calculates and reports one CQI in each report unit in the frequency domain when the RI is equal to 1;

and the report module calculates and reports CQI respectively for two codewords in each report unit in the frequency domain when the RI is larger than 1.

12. The user equipment according to claim 7, wherein the transmission mode module determining that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of

17. The user equipment according to claim 8, wherein the transmission mode module determining that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of

18. The user equipment according to claim 9, wherein the transmission mode module determining that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of

19. The user equipment according to claim 10, wherein the transmission mode module determining that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of

20. The user equipment according to claim 11, wherein the transmission mode module determining that the eNB is to map data of PDSCH onto P (number) CSI-RS ports for transmission according to the scheme as represented in the formula of