Dynamic channel quality measurement procedures for optimizing data transmission in a wireless digital communication system

• US 7,209,711 B2
• Filed: 01/30/2004
• Issued: 04/24/2007
• 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:
  US10/768,313
• Publication Number:
  US 20040185862A1
• Time in Patent Office: 1,180 Days
• Field of Search: 455/452.2, 455/62, 455/67.11, 455/509, 455/450, 455/512, 455/456.2
• US Class Current: 455/67.11
• 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

Data transmission is optimized in a wireless digital communication system including a base station and a plurality of user equipment mobile terminals (UEs). Adaptive modulation and coding (AM&C) is employed 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 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. A method for optimizing data transmission in a wireless digital communication system including a base station and a plurality of user equipment (UEs), wherein a first subset of the UEs have pending downlink transmissions and a second subset of the UEs do not have pending downlink transmissions, the method comprising:

(a) receiving blocks of downlink data at the base station for distribution to the plurality of UEs in the first subset;

(b) transmitting from the base station to at least one UE in the first subset a request to begin downlink channel quality measurements, whereby the base station does not transmit a request to begin downlink channel quality measurements to the UEs in the second subset due to not having pending downlink transmissions;

(c) the at least one UE in the first subset measuring and reporting the downlink channel quality to the base station;

(d) the at least one UE in the first subset receiving a downlink physical channel allocation signal from the base station;

(e) the at least one UE in the first subset setting up transmission parameters based on the downlink physical channel allocation; and

(f) the at least one UE in the first subset receiving blocks of the downlink data from the base station in accordance with the downlink physical channel allocation.

2. The method of claim 1 wherein the allocation signal indicates a particular coding rate, modulation type and at least one allocated time slot.

3. The method of claim 1 further including:

(g) prioritizing transmissions to be made from the base station to respective ones of the plurality of UEs in the first subset.

4. A wireless digital communication system for optimizing data transmission, the system comprising:

(a) a plurality of user equipment (UEs), wherein a first subset of the UEs have pending downlink transmissions and a second subset of the UEs do not have pending downlink transmissions; and

(b) a base station in communication with the UEs, the base station further comprising;

(b1) means for receiving blocks of downlink data for distribution to the plurality of UEs;

(b2) means for transmitting to at least one of the UEs in the first subset a request to begin downlink channel quality measurements, whereby the base station does not transmit a request to begin downlink channel quality measurements to the UEs in the second subset due to not having pending downlink transmissions;

(b3) means for receiving from the at least one UE in the first subset a report of the results of the downlink channel quality measurements;

(b4) means for transmitting to the at least one UE in the first subset a downlink physical channel allocation signal; and

(b5) means for transmitting to the at least one UE in the first subset blocks of the downlink data from the base station in accordance with the downlink physical channel allocation signal.

5. The system of claim 4 wherein the allocation signal indicates a particular coding rate, modulation type and at least one allocated time slot.

6. The system of claim 4 wherein the base station further includes:

(b6) means for prioritizing transmissions to be made to respective ones of the plurality of UEs in the first subset.

7. A method for optimizing data transmission in a wireless digital communication system including a base station and a plurality of wireless devices, wherein a first subset of the wireless devices have pending downlink transmissions and a second subset of the wireless devices do not have pending downlink transmissions, the method comprising:

(a) receiving blocks of downlink data at the base station for distribution to a plurality of wireless devices in the first subset;

(b) transmitting from the base station to a wireless device in the first subset, a request to begin downlink channel quality measurements, whereby the base station does not transmit a request to begin downlink channel quality measurements to the wireless devices in the second subset due to not having pending downlink transmissions;

(c) the wireless device in the first subset measuring and reporting the downlink channel quality to the base station;

(d) the base station signaling a downlink physical channel allocation to the wireless device in the first subset;

(e) the wireless device in the first subset setting up transmission parameters based on the downlink physical channel allocation; and

(f) the wireless device in the first subset receiving blocks of the downlink data from the base station in accordance with the downlink physical channel allocation.

8. The method of claim 7 wherein the signaled allocation indicates a particular coding rate, modulation type and at least one allocated time slot.

9. The method of claim 7 further including:

(g) prioritizing transmissions to be made from the base station to respective ones of the plurality of wireless devices in the first subset.

10. A method for optimizing data transmission in a wireless digital communication system including a base station and a plurality of user equipment (UEs), wherein a first subset of the UEs have pending downlink transmissions and a second subset of the UEs do not have pending downlink transmissions, the method comprising:

(a) receiving blocks of downlink data at the base station for distribution to a plurality of UEs in the first subset;

(b) sending an allocation signal indicating parameters including a particular coding rate, modulation type and at least one allocated timeslot to ones of the UEs in the first subset;

(c) the UEs in the first subset setting up transmission characteristics based on the indicated parameters; and

(d) the UEs in the first subset receiving blocks of the downlink data from the base station in accordance with the parameters.

11. The method of claim 10 wherein the blocks of data are distributed from the base station to the UEs on a prioritized basis.

12. The method of claim 10 further comprising:

(e) transmitting from the base station to the UEs in the first subset, a request to begin downlink channel quality measurements; and

(f) the UEs measuring and reporting the downlink channel quality to the base station, wherein the UEs are prioritized based on the downlink channel quality measurements.

13. A wireless digital communication system for optimizing data transmission, the system comprising:

(a) a base station; and

(b) a plurality of user equipment (UEs) in communication with the 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, each UE further comprising;

(b1) means for receiving a request from the base station to begin downlink channel quality measurements if the respective UE belongs to the first subset, whereby the base station does not transmit a request to begin downlink channel quality measurements to the UEs in the second subset due to not having pending downlink transmissions;

(b2) means for measuring and reporting the downlink channel quality to the base station;

(b3) means for receiving a downlink physical channel allocation signal from the base station;

(b4) means for setting up transmission parameters based on the downlink physical channel allocation signal; and

(b5) means for receiving blocks of the downlink data from the base station in accordance with the set transmission parameters.

14. The system of claim 13 wherein the allocation signal indicates a particular coding rate, modulation type and at least one allocated time slot.