Systems and methods for downlink scheduling that mitigate PDCCH congestion

• US 10,368,343 B2
• Filed: 05/27/2015
• Issued: 07/30/2019
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Sarkar, Debasish, Sen, Ayan, Singh, Jaspal, Singh, Narendra Kumar
• Primary Examiner(s): Solinsky, Peter G
• Application Number:
  US14/722,386
• Publication Number:
  US 20160353415A1
• Time in Patent Office: 1,525 Days
• Field of Search: 370336
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/1273 of downlink data flows
• 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

Abstract

Systems and methods are disclosed for improving Physical Downlink Control Channel (PDCCH) allocation for improved downlink scheduling. In some embodiments, a method of operation of a network node in a cellular communications network comprises transmitting a downlink assignment to a wireless device, the downlink assignment comprising an indication of whether the downlink assignment applies to a single Transmit Time Interval (TTI) or multiple consecutive TTIs, and transmitting a downlink data transmission to the wireless device during a single TTI or multiple downlink data transmissions to the wireless device during multiple consecutive TTIs according to the downlink assignment. In this manner, the network node does not need to transmit, and the wireless device does not need to receive/decode, a separate downlink assignment in each TTI. This may be beneficial to, e.g., mitigate PDCCH congestion.

Claims

1. A method of operation of a network node in a cellular communications network, comprising:

transmitting a downlink assignment to a wireless device, the downlink assignment comprising an indication of whether the downlink assignment applies to a single transmit time interval or multiple consecutive transmit time intervals;

transmitting a downlink data transmission to the wireless device during a single transmit time interval or multiple downlink data transmissions to the wireless device during multiple consecutive transmit time intervals according to the downlink assignment where the multiple downlink data transmissions comprise at least two different data values;

determining whether the wireless device supports multiple transmit time interval downlink assignment;

determining whether a service type of a service associated with the downlink transmission to the wireless device is a guaranteed bit rate service type; and

upon determining that the wireless device supports multiple transmit time interval downlink assignment and determining that the service type of the service associated with the downlink transmission to the wireless device is a guaranteed bit rate service type;

determining a number of consecutive transmit time intervals to be scheduled for downlink data transmission to the wireless device, the determined number of consecutive transmit time intervals being greater than or equal to 1; and

scheduling the multiple downlink data transmissions to the wireless device during the determined number of consecutive transmit time intervals.

2. The method of claim 1 wherein the indication in the downlink assignment indicates that the downlink assignment applies to multiple consecutive transmit time intervals, and transmitting comprises transmitting multiple downlink data transmissions to the wireless device during the multiple consecutive transmit time intervals according to the downlink assignment.

3. The method of claim 2 wherein the downlink assignment assigns the same physical resources for the multiple downlink data transmissions in the multiple consecutive transmit time intervals.

4. The method of claim 2 wherein:

transmitting the downlink assignment to the wireless device comprises transmitting the downlink assignment to the wireless device during a first transmit time interval of the multiple consecutive transmit time intervals; and

transmitting the multiple downlink data transmissions to the wireless device during the multiple consecutive transmit time intervals comprises;

transmitting a first downlink data transmission to the wireless device during the first transmit time interval according to the downlink assignment transmitted during the first transmit time interval; and

transmitting a second downlink data transmission to the wireless device during a second transmit time interval of the multiple consecutive transmit time intervals according to the downlink assignment transmitted during the first transmit time interval.

5. The method of claim 1 wherein transmitting the downlink assignment to the wireless device comprises transmitting the downlink assignment to the wireless device via a downlink control information message comprising the indication of whether the downlink assignment applies to a single transmit time interval or multiple consecutive transmit time intervals.

6. The method of claim 5 wherein, if the indication indicates that the downlink assignment applies to multiple consecutive transmit time intervals, the indication is further indicative of the number of consecutive transmit time intervals in the multiple consecutive transmit time intervals.

7. The method of claim 1 wherein, if the indication indicates that the downlink assignment applies to multiple consecutive transmit time intervals, the indication is further indicative of the number of consecutive transmit time intervals in the multiple consecutive transmit time intervals.

8. The method of claim 1 wherein determining the number of consecutive transmit time intervals comprises determining the number of consecutive transmit time intervals to be scheduled for downlink data transmission to the wireless device based on channel quality information reported by the wireless device.

9. The method of claim 1 wherein scheduling the downlink data transmissions to the wireless device for the multiple consecutive transmit time intervals further comprises:

determining whether a multiple transmit time interval assignment procedure is to be performed for the wireless device;

wherein determining the number of consecutive transmit time intervals to be scheduled for downlink data transmission to the wireless device and scheduling the multiple downlink data transmissions to the wireless device during the determined number of consecutive transmit time intervals are performed upon determining that the multiple transmit time interval assignment procedure is to be performed for the wireless device.

10. The method of claim 1 wherein the determined number of consecutive transmit time intervals is greater than or equal to 2.

11. A network node for a cellular communications network, comprising:

at least one radio unit;

one or more processors; and

memory storing instructions executable by the one or more processors whereby the network node is operative to;

transmit, via the at least one radio unit, a downlink assignment to a wireless device, the downlink assignment comprising an indication of whether the downlink assignment applies to a single transmit time interval or multiple consecutive transmit time intervals;

transmit, via the at least one radio unit, a downlink data transmission to the wireless device during a single transmit time interval or multiple downlink data transmissions to the wireless device during multiple consecutive transmit time intervals according to the downlink assignment where the multiple downlink data transmissions comprise at least two different data values;

determine whether the wireless device supports multiple transmit time interval downlink assignment;

determine whether a service type of a service associated with the downlink transmission to the wireless device is a guaranteed bit rate service type; and

upon determining that the wireless device supports multiple transmit time interval downlink assignment and determining that the service type of the service associated with the downlink transmission to the wireless device is a guaranteed bit rate service type;

determine a number of consecutive transmit time intervals to be scheduled for downlink data transmission to the wireless device, the determined number of consecutive transmit time intervals being greater than or equal to 1; and

schedule the multiple downlink data transmissions to the wireless device during the determined number of consecutive transmit time intervals.

12. The network node of claim 11 wherein the indication in the downlink assignment indicates that the downlink assignment applies to multiple consecutive transmit time intervals, and the network node transmits multiple downlink data transmissions to the wireless device during the multiple consecutive transmit time intervals according to the downlink assignment.

13. The network node of claim 12 wherein the downlink assignment assigns the same physical resources for the multiple downlink data transmissions in the multiple consecutive transmit time intervals.

14. The network node of claim 11 wherein the network node is further operative to transmit the downlink assignment to the wireless device via a downlink control information message comprising the indication of whether the downlink assignment applies to a single transmit time interval or multiple consecutive transmit time intervals.

15. The network node of claim 14 wherein, if the indication indicates that the downlink assignment applies to multiple consecutive transmit time intervals, the indication is further indicative of the number of consecutive transmit time intervals in the multiple consecutive transmit time intervals.

16. The network node of claim 11 wherein, if the indication indicates that the downlink assignment applies to multiple consecutive transmit time intervals, the indication is further indicative of the number of consecutive transmit time intervals in the multiple consecutive transmit time intervals.

17. The network node of claim 11 wherein the network node is further operative to determine a number of consecutive transmit time intervals to be scheduled for downlink data transmission to the wireless device, the determined number of consecutive transmit time intervals being greater than or equal to 1.

18. The network node of claim 17 wherein the determined number of consecutive transmit time intervals is greater than or equal to 2.

19. The network node of claim 17 wherein the network node determines the number of consecutive transmit time intervals to be scheduled for downlink data transmission to the wireless device based on channel quality information reported by the wireless device.

20. A method of operation of a wireless device in a cellular communications network, comprising:

receiving a downlink assignment from a network node, the downlink assignment comprising an indication of whether the downlink assignment applies to a single transmit time interval or multiple consecutive transmit time intervals; and

determining whether the downlink assignment is in a format that supports multiple consecutive transmit time interval assignment;

upon determining that the downlink assignment is in a format that supports multiple consecutive transmit time interval assignment;

determining a number of consecutive transmit time intervals being scheduled by the downlink assignment based on the indication comprised in the downlink assignment, the number of consecutive transmit time intervals being greater than or equal to 1;

receiving one or more downlink data transmissions on the determined number of consecutive transmit time intervals according to the downlink assignment where the multiple downlink data transmissions comprise at least two different data values.

21. The method of claim 20 wherein the indication in the downlink assignment indicates that the downlink assignment applies to multiple consecutive transmit time intervals, and receiving comprises receiving multiple downlink data transmissions during the multiple consecutive transmit time intervals according to the downlink assignment.

22. The method of claim 21 wherein the downlink assignment assigns the same physical resources for the multiple downlink data transmissions in the multiple consecutive transmit time intervals.

23. The method of claim 21 wherein:

receiving the downlink assignment comprises receiving the downlink assignment during a first transmit time interval of the multiple consecutive transmit time intervals; and

receiving the multiple downlink data transmissions during the multiple consecutive transmit time intervals comprises;

receiving a first downlink data transmission during the first transmit time interval according to the downlink assignment received during the first transmit time interval; and

receiving a second downlink data transmission during a second transmit time interval of the multiple consecutive transmit time intervals according to the downlink assignment received during the first transmit time interval.

24. The method of claim 20 wherein receiving the downlink assignment comprises receiving the downlink assignment via a downlink control information message comprising the indication of whether the downlink assignment applies to a single transmit time interval or multiple consecutive transmit time intervals.

25. The method of claim 24 wherein, if the indication indicates that the downlink assignment applies to multiple consecutive transmit time intervals, the indication is further indicative of the number of consecutive transmit time intervals in the multiple consecutive transmit time intervals.

26. The method of claim 20 wherein, if the indication indicates that the downlink assignment applies to multiple consecutive transmit time intervals, the indication is further indicative of the number of consecutive transmit time intervals in the multiple consecutive transmit time intervals.

27. A wireless device for operation in a cellular communications network, comprising:

at least one receiver;

at least one processor; and

memory containing instructions executable by the at least one processor whereby the wireless device is operative to;

receive, via the at least one receiver, a downlink assignment from a network node, the downlink assignment comprising an indication of whether the downlink assignment applies to a single transmit time interval or multiple consecutive transmit time intervals;

determine whether the downlink assignment is in a format that supports multiple consecutive transmit time interval assignment;

upon determining that the downlink assignment is in a format that supports multiple consecutive transmit time interval assignment;

determine a number of consecutive transmit time intervals being scheduled by the downlink assignment based on the indication comprised in the downlink assignment, the number of consecutive transmit time intervals being greater than or equal to 1; and

receive, via the at least one receiver, one or more downlink data transmissions on a single transmit time interval or multiple downlink data transmissions during multiple consecutive transmit time intervals according to the downlink assignment where the multiple downlink data transmissions comprise at least two different data values.

28. The wireless device of claim 27 wherein the indication in the downlink assignment indicates that the downlink assignment applies to multiple consecutive transmit time intervals, and the wireless device is further operative to receive multiple downlink data transmissions during the multiple consecutive transmit time intervals according to the downlink assignment.

29. The wireless device of claim 28 wherein the downlink assignment assigns the same physical resources for the multiple downlink data transmissions in the multiple consecutive transmit time intervals.

30. The wireless device of claim 27 wherein the wireless device is further operative to receive the downlink assignment via a downlink control information message comprising the indication of whether the downlink assignment applies to a single transmit time interval or multiple consecutive transmit time intervals.

31. The wireless device of claim 30 wherein, if the indication indicates that the downlink assignment applies to multiple consecutive transmit time intervals, the indication is further indicative of the number of consecutive transmit time intervals in the multiple consecutive transmit time intervals.

32. The wireless device of claim 27 wherein, if the indication indicates that the downlink assignment applies to multiple consecutive transmit time intervals, the indication is further indicative of the number of consecutive transmit time intervals in the multiple consecutive transmit time intervals.