Channel quality measurements for downlink resource allocation

• US 20030016641A1
• Filed: 05/14/2002
• Published: 01/23/2003
• Est. Priority Date: 05/14/2001
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Zeira, Eldad, Dick, Stephen G., Terry, Stephen E., Miller, James M., Zeira, Ariela
• Granted Patent: US 8,199,726 B2
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: H04B 17/327 Received signal code power [RSCP]
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0027 Scheduling of signalling, e.g. occurrence thereof
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

In a wireless digital communication system which may employ CDMA technology, a method and system for obtaining channel quality (CQ) measurements for downlink resource allocation wherein a User Equipment (UE) continuously measures RSCP based on a communication on a reference channel provided by the network. The UE measures timeslot ISCP either continuously, by configuration or by rotation and reports downlink CQ. The UE may report the RSCP once and the ISCP per timeslot, or may report some function of the RSCP/ISCP ratio such as modulation parameters or combined coding of all timeslots.

Claims

1. A method for providing channel quality (CQ) measurements for allocation of downlink resources between at least one user equipment (UE) and a base station in a wireless digital communications system employing code-division multiple access (CDMA) technology, said method comprising the steps of:

(a) said base station transmitting a signal to the UE for use by said UE to perform a measurement;

(b) said UE performing a first measurement of received signal code power (RSCP) responsive to receipt of the signal from said base station transmitted at step (a);

(c) said UE, performing a second measurement of interference signal code power (ISCP) responsive to receipt of the signal from said base station transmitted at step (a); and

(d) said UE, transmitting a CQ signal comprising RSCP and ISCP values to said base station in a specific format;

whereby said first and second measurements and said format are preselected.

2. The method of claim 1 wherein said first measurement further comprises continuously measuring RSCP.

3. The method of claim 1 further comprising using said first and second measurements to generate a ratio of RSCP/ISCP, whereby said format comprises said ratio.

4. The method of claim 1 wherein said transmitting further comprises transmitting both RSCP and ISCP measurements to the base station.

5. The method of claim 1 wherein said second measurement comprises detecting soft symbol errors.

6. The method of claim 1 wherein said format includes said first and second measurements for each timeslot.

7. The method of claim 1 further comprising generating a ratio of RSCP/ISCP and transmitting modulation parameters to the base station based upon said ratio.

8. The method of claim 1 wherein said base station, responsive to the CQ signal received from the UE, adjusts the power level employed for transmission to the UE.

9. The method of claim 1 further comprising separately coding said first and second measurements such that said format comprises a common CQ for all timeslots and a differential CQ for each timeslot.

10. The method of claim 1 wherein said format includes a mean of the ISCP for all of the channels and a difference from the mean for each channel.

11. The method of claim 1 wherein said format includes a mean of the RSCP for all of the channels and a difference from the mean for each channel.

12. The method of claim 1 wherein said first and second measurements include measuring a different group of timeslots in each frame over N frames and repeating this pattern for every N frames.

13. The method of claim 1 wherein said format comprises one of a given set of MCS levels.

15. The system of claim 14 wherein said first measuring means continuously measures RSCP.

16. The system of claim 14 wherein said UE further includes means for generating a ratio RSCP/ISCP, and whereby said format comprises said ratio.

17. The system of claim 14 wherein said format comprises a selected one of a plurality of MCS levels.

18. The system of claim 14 wherein said format includes a mean of all of the CQ measurements and the deviation from the mean for each of the CQ measurements.

19. The system of claim 14 wherein said format includes an average of the CQ measurements and the deviations from the average for each of the CQ measurements.

14. A wireless digital communications system employing code-division multiple access (CDMA) technology for obtaining channel quality (CQ) measurements for downlink resource allocation of a network to at least one User Equipment (UE), said method comprising:

(a) said network including means for transmitting a signal to the UE for use by said UE to perform a measurement;

(b) said UE having first measuring means for measuring received signal code power (RSCP) responsive to receipt of the signal from said network;

(c) said UE having second measuring means for measuring interference signal code power (ISCP) responsive to receipt of the signal from said network; and

(d) said UE having means for transmitting downlink CQ in accordance with a predetermined format.

20. A UE employing code-division multiple access (CDMA) and a repeating frame structure, each frame having a plurality of timeslots, for providing channel quality (CQ) measurements comprising:

means for receiving a signal to perform a measurement;

means for measuring received signal code power (RSCP) and interference signal code power (ISCP), responsive to receipt of the signal;

format means for receiving said RSCP and ISCP measurements and formatting said RSCP and ISCP measurements in accordance with a predetermined format; and

a transmitter for transmitting at least one of said RSCP and ISCP measurements in said predetermined format.

21. The UE of claim 20 wherein said measuring means continuously measures RSCP.

22. The UE of claim 20 wherein said predetermined format comprises a ratio of RSCP/ISCP.

23. The UE of claim 20 wherein said predetermined format comprises both RSCP and ISCP measurements.

24. The UE of claim 20 further comprising said measuring means detecting soft symbol errors in said signal.

25. The UE of claim 20 wherein said predetermined format comprises RSCP and ISCP for each timeslot.

26. The UE of claim 20 wherein said predetermined format comprises a mean of the ISCP for all of the timeslots and a difference from the mean for each timeslot.

27. The UE of claim 20 wherein said predetermined format comprises a mean of the RSCP for all of the timeslots and a difference from the mean for each timeslot.

28. The UE of claim 20 wherein said measuring means measures a different group of timeslots in each frame over N frames and repeats this pattern for every N frames.

29. The UE of claim 20 wherein said predetermined format comprises one of a plurality of MCS levels.