METHOD AND APPARATUS FOR CHANNEL QUALITY INDICATOR REPORT

• US 20090196190A1
• Filed: 12/22/2006
• Published: 08/06/2009
• Est. Priority Date: 12/23/2005
• Status: Active Grant

• Current Assignee: Beijing Samsung Telecom R&D Center (Samsung Electronics Co. Ltd.), Samsung Electronics Co. Ltd.
• Original Assignee: Beijing Samsung Telecom R&D Center (Samsung Electronics Co. Ltd.), Samsung Electronics Co. Ltd.
• Inventors: Li, Xiaoqiang, Lee, Ju-Ho, Zhang, Yujian, Sun, Chengjun
• Granted Patent: US 7,885,202 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 1/0029 Reduction of the amount of signalling, e.g. retention of useful signalling or differential signalling power control H04W52/04
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated

Abstract

A method for a UE reporting a CQI comprising steps of: obtaining a total number M of CQI report sub-bands in a system and a number N of CQI report sub-bands needed to be reported; measuring channel qualities of all sub-bands and according to the measurement result, determining N CQI report sub-bands needed to be reported and corresponding CQI values; sending a L-bit long sequence to a base station for indicating the sub-bands that need to be reported; sending CQI values corresponding to the sub-bands need to be reported to the base station. The present invention uses comparatively shorter bit sequence to indicate CQI report sub-bands needed to be reported and reduces the number of information bits necessary for CQI report sub-bands and also reduces the number of information bits corresponding to the CQI values in the CQI report sub-bands.

Claims

1. A method for a UE reporting a Channel Quality Indicator comprising steps of:

a) the UE obtaining a total number M of CQI report sub-bands in a system and a number N of CQI report sub-bands needed to be reported;

b) the UE measuring channel qualities of all sub-bands and according to the measurement result, the UE determining N CQI report sub-bands needed to be reported and the corresponding CQI values;

c) the UE sending a L-bit long sequence to a base station for indicating the sub-bands that need to be reported, and the length of the sequence is;

L=[log₂C_M^N]; and

d) the UE sending CQI values corresponding to the sub-bands needed to be reported to the base station.

2. The method according to claim 1, wherein the value of the M is obtained through dividing a transmission bandwidth in the system by a bandwidth in the CQI report sub-band, and N is no less than zero, but less than M.

3. The method according to claim 1, wherein in step c), the UE finds out the L-bit long sequence corresponding to sub-bands combination that needs to be reported for indication according to the corresponding relationship between the L=[log₂C_M^N] bits long sequence and combination formed by selecting N report sub-bands from M ones.

4. The method according to claim 1, wherein the indication of the indexes of the reported sub-bands via the L-bit long sequence accompanies with the report of the CQI values in corresponding sub-bands.

5. The method according to claim 1, wherein after the indication of the reported CQI sub-bands with the L bit long sequence, several times of the indication of corresponding CQI values will be transmitted.

6. The method according to claim 1, wherein in step c), the UE transmits the L-bit long sequence for the indication of reported sub-bands to the base station via physical layer signaling.

7. The method according to claim 1, wherein in step c), the UE transmits the L-bit long sequence for the indication of reported sub-bands to the base station via high level layer signaling.

8. The method according to claim 1, wherein in step d), transmitting report CQI values in sub-bands comprising steps of:

indicating a index of the CQI report sub-band bearing a maximum CQI value and the maximum CQI value;

indicating differential values between the maximum CQI value and CQI values in other CQI report sub-bands.

9. The method according to claim 1, wherein a corresponding relationship table is stored in both the UE and the base station.

10. The method according to claim 1, wherein a corresponding relationship is determined by:

the UE obtaining a total number M of CQI report sub-bands in the system and the number N of CQI report sub-bands needed to be reported;

generating all possible M-bit long sequences whose N bits are set as “

1”

;

sorting the generated sequences according to their binary values;

the UE measuring channel qualities for all sub-bands;

selecting N CQI report sub-bands bearing optimal channel qualities as the N sub-bands to be reported, and determining a M-bit long bit-mapped sequence whose N bits are set as “

1”

corresponding to the combinations formed by selecting N sub-bands from the M CQI report sub-bands;

according to the M-bit long sequence whose N bits are set as “

1”

, finding out its sequence number among the sorted all M-bit long sequences whose N bits are set as “

1”

; and

converting the decimal of the sequence number into a L-bit long binary sequence, which is the desired L-bit long sequence.

11. A method for a base station identifying Channel Quality Indication reported by a UE comprising steps of:

a) the base station receiving CQI signaling reported from the UE via a CQI report channel;

b) the base station extracting a L-bit long sequence indicating CQI report sub-bands from the CQI report signaling, and according to a relationship between combinations formed by picking N CQI report sub-bands out from M CQI report sub-bands and the L-bit long sequence, determining the CQI of which N sub-bands is reported by the UE; and

c) obtaining CQI values of the report sub-bands extracted from the CQI signaling transmitted from the UE.

12. The method according to claim 11, wherein the base station obtains a total number of sub-bands in the system and the number of sub-bands required to be reported through standard specification or through signaling notification from a network entity.

13. The method according to claim 11, wherein in step b), according to a corresponding relationship between the L=[log₂C_M^N] long sequence and the combinations formed through selecting N sub-bands from M ones, the N report sub-bands indicated by the L-bit long sequence is determined.

14. The method according to claim 11, wherein in step c), extracting the CQI values of the CQI report sub-bands in the CQI signaling from the UE comprising steps of:

determining which sub-band bears the maximum CQI value among N CQI report sub-bands according to the extracted information bits that indicate the index of the sub-band bearing the maximum CQI value;

determining the reported maximum CQI value according to the worked out information bits that indicate the maximum CQI value;

determining the CQI values for the other N-1 CQI report sub-bands according to the calculated maximum CQI value and the difference bits that indicate the difference values between CQI values in the other N-1 CQI report sub-bands and the maximum CQI value.

15. The method according to claim 13, wherein the base station obtains the corresponding relationship between the base station and the UE according to a corresponding relationship table stored in both the UE and the base station.

16. The method according to claim 13, wherein the determination of the corresponding relationship comprising steps of:

the base station obtaining a total number M of CQI report sub-bands in the system and the number N of CQI report sub-band that need to be reported;

the base station generating all possible M-bit long sequences whose N bits are set as “

1”

;

sorting the generated sequences according to their binary values;

the base station receiving the CQI report signaling from the UE;

extracting the L-bit long sequence from the CQI report signaling;

converting this L-bit long sequence into a decimal number, and locating the sequence from all M-bit long sequences whose N bits are set as “

1”

according to the decimal value of the its sequence number.

17. An apparatus for a UE reporting Channel Quality Indication comprising an antenna, a RF receiver, an ADC, a guard spacing removing unit, an OFDM demodulation unit, further comprising:

a) a pilot signal-to-noise ratio measuring unit for measuring channel qualities of all sub-bands;

b) a UE control and process unit for determining frequency bands that need to be reported according to the channel qualities of all measured sub-bands, and according to a total number of sub-bands and a number of sub-bands that need to be reported, determining a bit sequence for the indication of report sub-bands and information bits for the indication of report CQI values to generate CQI report signaling; and

c) a transmitter for transmitting the generated CQI report signaling to a base station.