Dynamic channel quality measurement procedure implemented by user equipment for adaptive modulation and coding techniques

• US 7,127,256 B2
• Filed: 01/30/2004
• Issued: 10/24/2006
• Est. Priority Date: 05/14/2001
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Zeira, Eldad, Dick, Stephen G., Terry, Stephen E., Miller, James M., Zeira, Ariela
• Primary Examiner(s): Milord, Marceau
• Application Number:
  US10/768,223
• Publication Number:
  US 20040185789A1
• Time in Patent Office: 998 Days
• Field of Search: 455/67.11, 455/452.2, 455/450, 455/456.5, 455/509, 455/524, 455/452.1, 455/512, 455/456.2, 455/62
• US Class Current: 455/452.2
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover
• 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: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 72/543 based on requested quality, e.g. QoS
• CPC Class Codes: H04W 72/56 based on priority criteria

Abstract

A wireless digital communication method for a plurality of user equipment mobile terminals (UEs) to communicate with a base station. Adaptive modulation and coding (AM&C) is used to achieve improved radio resource utilization and provide optimum data rates for user services. Blocks of downlink (DL) data are received by the base station which requests downlink DL channel quality measurements only from those mobile terminals (UEs) with pending downlink transmissions. The UEs respond to the request by measuring and reporting DL channel quality to the base station, which then allocates resources such that the UEs will make best use of radio resources. The base station notifies the UEs of the physical channel allocation indicating the modulation/coding rate and allocated slots followed by transmission of blocks of downlink data which are transmitted to the UEs.

Claims

1. In a wireless communication system including a plurality of user equipment mobile terminals (UEs) and a base station, wherein a first subset of the UEs have pending downlink transmissions and a second subset of the UEs do not have pending downlink transmissions, a method of minimizing overhead signaling and optimizing radio resource utilization by restricting the transmission of channel quality measurement requests to only those UEs that have pending downlink transmissions so as to avoid unnecessary channel quality measurements performed by the UEs and also avoid unnecessary channel quality measurement requests transmitted by the base station, the method comprising:

(a) each of the UEs in the first subset receiving from the base station a request to begin channel quality measurements, whereby the base station does not transmit a request to begin channel quality measurements to the UEs in the second subset due to not having pending downlink transmissions;

(b) each of the UEs in the first subset performing channel quality measurements and transmitting to the base station the results of the channel quality measurements, whereby the UEs in the second subset do not perform channel quality measurements because they did not receive a request to begin channel quality measurements from the base station due to not having pending downlink transmissions; and

(c) the base station allocating radio resources used by the UEs in the first subset in response to the results of the channel quality measurements transmitted to the base station by the UEs in the first subset.

2. The method of claim 1 further comprising:

(d) each of the UEs in the first subset receiving a communication signal from the base station that indicates a particular coding rate, modulation type and at least one allocated time slot.

3. The method of claim 2 wherein each of the UEs in the first subset prepare for reception of downlink data from the base station by setting reception parameters in accordance with the particular coding rate, the modulation type and the at least one allocated time slot indicated by the communication signal.

4. The method of claim 1 wherein the base station determines which of the UEs in the first subset will make the best use of radio resources.

5. The method of claim 4 wherein the base station further determines specific time slots that the UEs in the first subset should use to receive downlink data from the base station.

6. The method of claim 1 wherein the request to begin channel quality measurements is sent by the base station to the UEs in the first subset in response to the base station receiving blocks of downlink data.

7. The method of claim 1 wherein the UEs that have pending downlink transmissions perform channel quality measurements until there are no longer pending downlink transmissions.

8. In a wireless communication system including a plurality of user equipment mobile terminals (UEs) and a base station, wherein a first subset of the UEs have pending downlink transmissions and a second subset of the UEs do not have pending downlink transmissions, a method of minimizing overhead signaling and optimizing radio resource utilization by restricting the transmission of channel quality measurement requests to only those UEs that have pending downlink transmissions so as to avoid unnecessary channel quality measurements performed by the UEs and also avoid unnecessary channel quality measurement requests transmitted by the base station, the method comprising:

(a) each of the UEs in the first subset receiving from the base station a request to begin channel quality measurements, whereby the base station does not transmit a request to begin channel quality measurements to the UEs in the second subset due to not having pending downlink transmissions;

(b) each of the UEs in the first subset performing channel quality measurements and transmitting to the base station the results of the channel quality measurements, whereby the UEs in the second subset do not perform channel quality measurements because they did not receive a request to begin channel quality measurements from the base station due to not having pending downlink transmissions;

(c) the base station determining which of the UEs in the first subset will make the best use of radio resources; and

(d) the base station sending downlink data only to the UEs determined in step (c).

9. The method of claim 8 further comprising:

(e) each of the UEs determined in step (c) receiving a communication signal from the base station that indicates a particular coding rate, modulation type and at least one allocated time slot.

10. The method of claim 9 wherein each of the UEs determined in step (c) prepare for reception of downlink data from the base station by setting reception parameters in accordance with the particular coding rate, the modulation type and the at least one allocated time slot indicated by the communication signal.

11. The method of claim 10 wherein the base station further determines specific time slots that the UEs determined in step (c) should use to receive downlink data from the base station.

12. The method of claim 8 wherein the request to begin channel quality measurements is sent by the base station to the UEs in the first subset in response to the base station receiving blocks of downlink data.

13. The method of claim 8 wherein the UEs that have pending downlink transmissions perform channel quality measurements until there are no longer pending downlink transmissions.

14. A wireless communication system for minimizing overhead signaling and optimizing radio resource utilization, the system comprising:

(a) a base station; and

(b) a plurality of user equipment mobile terminals (UEs), wherein the base station sends a request to begin channel quality measurements only to a first subset of the UEs that have pending downlink transmissions and not to a second subset of the UEs that do not have pending downlink transmissions, the UEs in the first subset perform channel quality measurements and transmit to the base station the results of the channel quality measurements, and the base station allocates radio resources used by the UEs in the first subset in response to the results of the channel quality measurements transmitted to the base station by the UEs in the first subset.

15. The system of claim 14 wherein each of the UEs in the first subset receives a communication signal from the base station that indicates a particular coding rate, modulation type and at least one allocated time slot.

16. The system of claim 15 wherein each of the UEs in the first subset prepares for reception of downlink data from the base station by setting reception parameters in accordance with the particular coding rate, the modulation type and the at least one allocated time slot indicated by the communication signal.

17. The system of claim 14 wherein the base station determines which of the UEs in the first subset will make the best use of radio resources.

18. The system of claim 14 wherein the base station further determines specific time slots that the UEs in the first subset should use to receive downlink data from the base station.

19. The system of claim 14 wherein the request to begin channel quality measurements is sent by the base station to the UEs in the first subset in response to the base station receiving blocks of downlink data.

20. The system of claim 14 wherein the UEs that have pending downlink transmissions perform channel quality measurements until there are no longer pending downlink transmissions.

21. A wireless communication system for minimizing overhead signaling and optimizing radio resource utilization, the system comprising:

(a) a base station; and

(b) a plurality of user equipment mobile terminals (UEs), wherein the base station sends a request to begin channel quality measurements only to a first subset of the UEs that have pending downlink transmissions and not to a second subset of the UEs that do not have pending downlink transmissions, the UEs in the first subset perform channel quality measurements and transmit to the base station the results of the channel quality measurements, and the base station sends downlink data to those UEs in the first subset that the base station determines will make the best use of radio resources.

22. The system of claim 21 wherein each of the UEs that the base station determines will make the best use of radio resources receives a communication signal from the base station that indicates a particular coding rate, modulation type and at least one allocated time slot.

23. The system of claim 22 wherein each of the UEs that the base station determines will make the best use of radio resources prepares for reception of downlink data from the base station by setting reception parameters in accordance with the particular coding rate, the modulation type and the at least one allocated time slot indicated by the communication signal.

24. The system of claim 21 wherein the base station further determines specific time slots that the UEs that the base station determines will make the best use of radio resources should use to receive downlink data from the base station.

25. The system of claim 21 wherein the request to begin channel quality measurements is sent by the base station to the UEs that the base station determines will make the best use of radio resources in response to the base station receiving blocks of downlink data.

26. The system of claim 21 wherein the UEs that have pending downlink transmissions perform channel quality measurements until there are no longer pending downlink transmissions.

27. In a wireless communication system including a plurality of user equipment mobile terminals (UEs) and a base station, wherein a subset of the UEs have pending downlink transmissions, a method of minimizing overhead signaling and optimizing radio resource utilization, the method comprising:

(a) each of the UEs in the subset receiving from the base station a request to begin channel quality measurements;

(b) each of the UEs in the subset transmitting to the base station the results of the channel quality measurements;

(c) the base station allocating radio resources used by the UEs in the subset in response to the results of the channel quality measurements; and

(d) each of the UEs in the subset receiving a communication signal from the base station that indicates a particular coding rate, modulation type and at least one allocated time slot, wherein each of the UEs in the subset prepare for reception of downlink data from the base station by setting reception parameters in accordance with the particular coding rate, the modulation type and the at least one allocated time slot indicated by the communication signal.

28. The method of claim 27 wherein the base station determines which of the UEs in the subset will make the best use of radio resources.

29. The method of claim 28 wherein the base station further determines specific time slots that the UEs in the subset should use to receive downlink data from the base station.

30. The method of claim 27 wherein the request to begin channel quality measurements is sent by the base station to the UEs in the subset in response to the base station receiving blocks of downlink data.

31. The method of claim 27 wherein the UEs that have pending downlink transmissions perform channel quality measurements until there are no longer pending downlink transmissions.

32. In a wireless communication system including a plurality of user equipment mobile terminals (UEs) and a base station, wherein a subset of the UEs have pending downlink transmissions, a method of minimizing overhead signaling and optimizing radio resource utilization, the method comprising:

(a) each of the UEs in the subset receiving from the base station a request to begin channel quality measurements;

(b) each of the UEs in the subset transmitting to the base station the results of the channel quality measurements;

(c) the base station determining which of the UEs in the subset will make the best use of radio resources;

(d) the base station sending downlink data only to the UEs determined in step (c); and

(e) each of the UEs determined in step (c) receiving a communication signal from the base station that indicates a particular coding rate, modulation type and at least one allocated time slot, wherein each of the UEs determined in step (c) prepare for reception of downlink data from the base station by setting reception parameters in accordance with the particular coding rate, the modulation type and the at least one allocated time slot indicated by the communication signal.

33. The method of claim 32 wherein the base station further determines specific time slots that the UEs determined in step (c) should use to receive downlink data from the base station.

34. The method of claim 32 wherein the request to begin channel quality measurements is sent by the base station to the UEs in the subset in response to the base station receiving blocks of downlink data.

35. The method of claim 32 wherein the UEs that have pending downlink transmissions perform channel quality measurements until there are no longer pending downlink transmissions.

36. A wireless communication system for minimizing overhead signaling and optimizing radio resource utilization, the system comprising:

(a) a base station; and

(b) a plurality of user equipment mobile terminals (UEs), wherein the base station sends a request to begin channel quality measurements only to a subset of the UEs that have pending downlink transmissions, the UEs in the subset transmit to the base station the results of the channel quality measurements, the base station allocates radio resources used by the UEs in the subset in response to the results of the channel quality measurements, and each of the UEs in the subset receives a communication signal from the base station that indicates a particular coding rate, modulation type and at least one allocated time slot, wherein each of the UEs in the subset prepares for reception of downlink data from the base station by setting reception parameters in accordance with the particular coding rate, the modulation type and the at least one allocated time slot indicated by the communication signal.

37. The system of claim 36 wherein the base station determines which of the UEs in the subset will make the best use of radio resources.

38. The system of claim 36 wherein the base station further determines specific time slots that the UEs in the subset should use to receive downlink data from the base station.

39. The system of claim 36 wherein the request to begin channel quality measurements is sent by the base station to the UEs in the subset in response to the base station receiving blocks of downlink data.

40. The system of claim 36 wherein the UEs that have pending downlink transmissions perform channel quality measurements until there are no longer pending downlink transmissions.

41. A wireless communication system for minimizing overhead signaling and optimizing radio resource utilization, the system comprising:

(a) a base station; and

(b) a plurality of user equipment mobile terminals (UEs), wherein the base station sends a request to begin channel quality measurements only to a subset of the UEs that have pending downlink transmissions, the UEs in the subset transmit to the base station the results of the channel quality measurements, the base station sends downlink data to those UEs in the subset that the base station determines will make the best use of radio resources, and each of the UEs that the base station determines will make the best use of radio resources receives a communication signal from the base station that indicates a particular coding rate, modulation type and at least one allocated time slot.

42. The system of claim 41 wherein each of the UEs that the base station determines will make the best use of radio resources prepares for reception of downlink data from the base station by setting reception parameters in accordance with the particular coding rate, the modulation type and the at least one allocated time slot indicated by the communication signal.

43. The system of claim 41 wherein the base station further determines specific time slots that the UEs that the base station determines will make the best use of radio resources should use to receive downlink data from the base station.

44. The system of claim 41 wherein the request to begin channel quality measurements is sent by the base station to the UEs that the base station determines will make the best use of radio resources in response to the base station receiving blocks of downlink data.

45. The system of claim 41 wherein the UEs that have pending downlink transmissions perform channel quality measurements until there are no longer pending downlink transmissions.