Reliability detection of channel quality indicator (CQI) and application to outer loop power control

• US 8,204,450 B2
• Filed: 08/22/2011
• Issued: 06/19/2012
• Est. Priority Date: 12/04/2002
• Status: Active Grant

• Current Assignee: Pantech Wireless, LLC (Ideahub, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Rudolf, Marian, Dick, Stephen G., Miller, James M.
• Primary Examiner(s): Dao, Minh D
• Application Number:
  US13/214,490
• Publication Number:
  US 20110299447A1
• Time in Patent Office: 302 Days
• Field of Search: 455/69, 455/562.1, 455/561, 370/335, 370/342, 370/328, 370/329
• US Class Current: 455/69
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0033 arrangements specific to the transmitter
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 2001/125 Arrangements for preventing errors in the return channel
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 28/24 Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 52/20 using error rate
• CPC Class Codes: H04W 52/262 taking into account adaptive modulation and coding [AMC] scheme AMC per se H04L1/0001
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method for determining a channel quality in wireless communications includes receiving a high speed shared control channel (HS-SICH) transmission. An expected number of HS-SICH transmissions and a number of unsuccessful HS-SICH transmissions are counted. The number of unsuccessful HS-SICH transmissions includes a number of failed HS-SICH transmissions and a number of missed HS-SICH transmissions. The expected number of HS-SICH transmissions and the number of unsuccessful HS-SICH transmissions over a fixed time period are periodically reported, whereby the reporting is an indication of the channel quality.

Claims

1. A method for performing outer loop power control in wireless communications, including:

receiving a channel quality indicator (CQI) message;

decoding the CQI message;

computing a decision metric value for each symbol in the CQI message;

determining whether the CQI message is erroneous;

counting a number of erroneous CQI messages; and

signaling a wireless/transmit receive unit to adjust an uplink transmission power on a condition that the number of erroneous CQI messages exceeds a threshold.

2. The method according to claim 1, wherein the determining includes:

selecting a largest decision metric value;

selecting a second largest decision metric value;

comparing the largest decision metric value and the second largest decision metric value against a threshold, wherein the CQI message is erroneous on a condition that the comparison result is below the threshold.

3. The method according to claim 2, wherein the decision metric values are logarithmic and the comparing includes determining a difference between the largest decision metric value and the second largest decision metric value.

4. The method according to claim 2, wherein the comparing includes calculating a ratio of the largest decision metric value to the second largest decision metric value.

5. The method according to claim 1, wherein the counting includes using at least one counter.

6. The method according to claim 1, wherein the counting includes counting a total number of high-speed shared control channels (HS-SICHs) received, a number of false HS-SICHs received, and a number of HS-SICHs that have been missed.

7. The method according to claim 1, wherein:

the counting is performed over a time interval; and

the signaling is performed after expiration of the time interval.

8. The method according to claim 1, wherein the method is performed by a radio network controller and the CQI message is received from a wireless transmit/receive unit.

9. The method according to claim 1, wherein the method is performed by a base station and the CQI message is received from a wireless transmit/receive unit.

10. A base station configured to perform outer loop power control, including:

a receiver configured to receive a channel quality indicator (CQI) message;

a decoder configured to decode the CQI message;

a processor configured to;

compute a decision metric value for each symbol in the CQI message; and

determine whether the CQI message is erroneous;

a counter configured to count a number of erroneous CQI messages; and

a transmitter configured to signal a wireless/transmit receive unit to adjust an uplink transmission power on a condition that the number of erroneous CQI messages exceeds a threshold.

11. The base station according to claim 10, wherein the processor is further configured to:

select a largest decision metric value;

select a second largest decision metric value;

compare the largest decision metric value and the second largest decision metric value against a threshold, wherein the CQI message is determined to be erroneous on a condition that the comparison result is below the threshold.

12. The base station according to claim 11, wherein the decision metric values are logarithmic and the processor is configured to determine a difference between the largest decision metric value and the second largest decision metric value.

13. The base station according to claim 11, wherein the processor is configured to calculate a ratio of the largest decision metric value to the second largest decision metric value.

14. The base station according to claim 10, wherein the counter is configured to count a total number of high-speed shared control channels (HS-SICHs) received, a number of false HS-SICHs received, and a number of HS-SICHs that have been missed.

15. The base station according to claim 10, wherein:

the counter is configured to count the number of erroneous CQI messages over a time interval; and

the transmitter is configured to signal the wireless transmit/receive unit after expiration of the time interval.

16. A radio network controller configured to perform outer loop power control, comprising:

a receiver configured to receive a channel quality indicator (CQI) message;

a decoder configured to decode the CQI message;

a processor configured to;

compute a decision metric value for each symbol in the CQI message; and

determine whether the CQI message is erroneous;

a counter configured to count a number of erroneous CQI messages; and

a transmitter configured to signal a wireless/transmit receive unit to adjust an uplink transmission power on a condition that the number of erroneous CQI messages exceeds a threshold.

17. The radio network controller according to claim 16, wherein the processor is further configured to:

select a largest decision metric value;

select a second largest decision metric value;

compare the largest decision metric value and the second largest decision metric value against a threshold, wherein the CQI message is determined to be erroneous on a condition that the comparison result is below the threshold.

18. The radio network controller according to claim 17, wherein the decision metric values are logarithmic and the processor is configured to determine a difference between the largest decision metric value and the second largest decision metric value.

19. The radio network controller according to claim 17, wherein the processor is configured to calculate a ratio of the largest decision metric value to the second largest decision metric value.

20. The radio network controller according to claim 16, wherein the counter is configured to count a total number of high-speed shared control channels (HS-SICHs) received, a number of false HS-SICHs received, and a number of HS-SICHs that have been missed.

21. The radio network controller according to claim 16, wherein:

the counter is configured to count the number of erroneous CQI messages over a time interval; and

the transmitter is configured to signal the wireless transmit/receive unit after expiration of the time interval.