Dynamic channel quality measurement procedure for adaptive modulation and coding techniques

• US 20020168944A1
• Filed: 12/21/2001
• Published: 11/14/2002
• Est. Priority Date: 05/14/2001
• Status: Active Grant

• 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
• Granted Patent: US 6,810,236 B2
• Time in Patent Office: Days
• 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

A wireless digital communication method for communicating between a base station and a plurality of user equipment mobile terminals (UEs) and employs adaptive modulation and coding (AM&C) 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. A method for optimizing radio resource utilization and adjusting data rates in a wireless digital communications system comprising a base station and plurality of mobile terminals (MTs), said method comprising the steps of:

(a) said base station, upon receipt of blocks of downlink data for at least one of said MTs, transmits to said MT a request for a channel quality measurement;

(b) said at least one MT receives said request;

(c) said at least one MT measures and reports the downlink channel quality to the base station;

(d) responsive to the channel quality measurement received from said at least one MT, said base station allocates the radio resources;

(e) said base station transmits to said at least one MT in accordance with said allocation.

2. The method of claim 1 whereby said allocation includes modulation type, coding rate and timeslot(s).

3. The method of claim 1 further including said at least one MT, responsive to receipt of said allocation, prepares for reception of downlink data in accordance with said allocation.

4. The method of claim 1 wherein method step (a) further includes said base station indicating specific slots for said measurement

5. The method of claim 4 wherein step (c) further comprises said base station including which slots said at least one MT has been allocated for transmission to the base station.

6. The method of claim 1 wherein step (c) further includes said base station indicating the allocated slots to be used by said at least one MT.

7. The method of claim 2 wherein said at least one MT receives a transmission by the base station according to said allocation.

8. A method for optimizing radio resource utilization and adjusting data rates in a wireless digital communications system comprising a base station and plurality of mobile terminals (MTs), said method comprising the steps of:

(a) said base station, upon receipt of blocks of downlink data intended for given ones of said MTs, transmitting to said given MTs a request for a channel quality measurement;

(b) said given MTs performing said requested measurement;

(c) said given MTs transmitting the channel quality measurements to the base station;

(d) responsive to the channel quality measurement data received from the given ones of MTs reporting downlink channel quality, said base station determining preferred ones of the given ones of MTs are capable of making best use of the radio resources;

(e) said base station allocating time slots to be used by the preferred MTs.

9. A method for optimizing radio resource utilization and adjusting data rates in a wireless digital communications system comprising a base station and plurality of mobile terminals (MTs), said method comprising the steps of:

(a) said base station, upon receipt of blocks of downlink data intended for given MTs, transmitting to given ones of said MTs a request for a channel quality measurement;

(b) said base station determining preferred ones of the given ones of the MTs are capable of making best use of the radio resources responsive to the channel quality measurement data received from the given ones of the MTs reporting downlink channel quality; and

(c) said base station allocating a given number of time slots to said preferred MTs according to the channel quality measurement data and the amount of downlink data available for transmission to said given MTs.

10. A wireless digital communications system comprising a base station and plurality of mobile terminals (MTs), comprising:

(a) said base station, having means for receipt of blocks of downlink data intended for given ones of said MTs and means for transmitting to said given ones of MTs a request for a channel quality measurement;

(b) the given ones of MTs receiving such a request having means for measuring downlink quality and means for reporting the measured downlink channel quality to the base station;

(c) said base station having means for determining preferred ones of the given one of MTs are capable of making best use of the radio resources responsive to the channel quality measurement data received from the given ones of MTs reporting downlink channel quality;

(d) said base station having further means for determining the modulation/coding rate for each preferred MT as a function of the channel quality measurement and for transmitting modulation/coding rate to the preferred MTs according to the channel quality measurement obtained from the respective preferred MT; and

(e) said base station transmitting, at the modulation/coding rate specified in step (d), blocks of downlink data to the preferred MTs.

11. The method of claim 10 wherein said MTs include means responsive to receipt of the channel allocation and modulation/coding rate information, to prepare for reception of downlink data according to specified channel allocation and modulation/coding rate.

13. The method of claim 12 wherein said preferred UEs include means, responsive to receipt of the channel allocation, to prepare for reception of downlink data according to specified channel allocation and modulation/coding rate.

15. The method of claim 14 wherein said preferred UEs include means, responsive to receipt of the channel allocation to prepare for reception of downlink data according to specified channel allocation and modulation/coding rates.

17. The method of claim 16 wherein method step (a) further includes said BS indicating specific required slots for said channel quality measurement.

18. The method of claim 16 whereby said allocation comprises modulation type, coding rate and timeslot(s).

19. The method of claim 16 further including said UEs, responsive to receipt of said allocation, prepare for reception of downlink data in accordance with said allocation.

20. The method of claim 16 wherein step (e) further comprises said BS transmitting said allocation to said UE.

21. The method of claim 16 wherein step (c) further includes said BS prioritizing said UEs from highest channel quality to lowest channel quality, and allocates slots first to the UEs reporting the highest quality channel.

22. The method of claim 21 wherein the UEs receive a transmission by the base station according to the allocation.

12. A wireless digital communications system comprising a base station and plurality of user equipment (UEs), comprising:

(a) said base station, having means for receiving blocks of downlink data intended for given ones of said UEs and means for transmitting to given UEs a request for a channel quality measurement;

(b) the given ones of UEs receiving such a request having means for measuring downlink channel quality and means for reporting the measured downlink channel quality to the base station;

(c) said base station, responsive to the channel quality measurement data received from the given ones of MTs reporting downlink channel quality, having means for determining preferred ones of the given ones of UEs are capable of making best use of the radio resources; and

(d) said base station having further means for allocating the time slots to the preferred UEs.

14. A wireless digital communications system comprising a base station (BS) and plurality of user equipment (UEs), comprising:

(a) said BS having means for receiving blocks of downlink data intended for given ones of said UEs and means for transmitting to the given ones of UEs a request for a channel quality measurement;

(b) the given ones of said UEs receiving such a request having means for measuring downlink channel quality and means for reporting the measured downlink channel quality to the BS;

(c) said BS having means for determining preferred ones of the given ones of UEs are capable of making best use of the radio resources, responsive to the channel quality measurement data received from the given ones of UEs reporting downlink channel quality; and

(d) said BS having further means for determining a modulation/coding rate for each said preferred ones of UEs as a function of the channel quality measurement and for transmitting said modulation/coding rate to the preferred ones of the UEs.

16. A method for optimizing radio resource utilization and adjusting data rates in a wireless digital communications system comprising a base station (BS) and plurality of user equipment (UEs), said method comprising the steps of:

(a) said BS, upon receipt of blocks of downlink data for at least one of said UEs, transmits to said UE a request for a channel quality measurement;

(d) said at least one UE receives said request;

(e) said at least one UE measures the downlink channel quality;

(d) said at least one UE reports the downlink channel quality to the BS;

(e) responsive to the channel quality measurement received from said at least one UE, said BS allocates the radio resources;

(f) said BS transmits to said at least one UE in accordance with said allocation.

23. A method for optimizing radio resource utilization in a wireless digital communications system comprising a base station (BS) and plurality of user equipment (UEs), said method comprising the steps of:

(a) said BS receiving at least one block of downlink (DL) data;

(b) said BS determining the specific UE to which the block of data is destined;

(c) said BS transmitting to said specific UE a request for a DL channel quality (CQ) measurement;

(d) said UE performing a measurement of the DL CQ;

(e) said UE transmitting said measurement to said BS;

(f) said base station prioritizing and allocating radio resources based upon said measurement;

(g) said base station transmitting said allocation to the UE;

(h) said UE adjusting in response to said allocation;

(i) said BS transmitting said DL data in accordance with said allocation; and

(j) said UE receiving said DL data.

24. A system for optimizing radio resource utilization in a wireless digital communications network comprising a base station (BS) and plurality of user equipment (UEs), said system comprising:

(a) means at said BS for receiving at least one block of downlink (DL) data;

(b) means at said BS for determining the specific UE to which the block of data is destined;

(c) means at said BS for transmitting to said specific UE a request for a DL channel quality (CQ) measurement;

(d) means at said UE for performing a measurement of the DL CQ;

(e) means at said UE for transmitting said measurement to said BS;

(f) means at said base station for prioritizing and allocating radio resources based upon said measurement;

(g) means at said base station for transmitting said allocation to the UE;

(h) means at said UE for adjusting in response to said allocation;

(i) means at said BS for transmitting said DL data in accordance with said allocation; and

said UE receiving said DL data.