Control channel design for machine type communications

• US 10,645,681 B2
• Filed: 10/19/2015
• Issued: 05/05/2020
• Est. Priority Date: 10/20/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Wanshi, Xu, Hao, Wang, Michael Mao, Gaal, Peter
• Primary Examiner(s): Baig, Adnan
• Application Number:
  US14/886,898
• Publication Number:
  US 20160112997A1
• Time in Patent Office: 1,660 Days
• Field of Search: None
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0087 when data requirements change
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 28/0215 based on user or device properties, e.g. MTC-capable devices services for machine-to-machine communication [M2M] or machine type communication [MTC] H04W4/70; wireless resource selection or allocation plan definition based on terminal or device properties H04W72/51
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

Aspects of the present disclosure provide techniques that may be applied in systems to allow for communication over a control channel utilizing a relatively narrow band (e.g., six physical resource blocks) based search space. An exemplary method, performed by a user equipment, generally includes identifying, within a subframe, a first search space to monitor for a downlink control channel that occupies a first number of physical resource blocks (PRBs) that represents a narrowband size and monitoring at least the first search space for the downlink control channel transmitted in the subframe.

Claims

1. A method for wireless communications by a user equipment (UE), comprising:

identifying, within a subframe, a first search space spanning a first number of physical resource blocks (PRBs) that represents a narrowband size;

monitoring the first search space for a first downlink control channel decoding candidate;

monitoring a second search space spanning a second number of PRBs for a second downlink control channel decoding candidate, wherein the second number of PRBs is fewer than the first number of PRBs; and

monitoring a third search space spanning a third number of PRBs for a third downlink control channel decoding candidate, wherein the third number of PRBs is fewer than the first number of PRBs and the second number of PRBs, wherein;

the first search space comprises a combination of the second search space and the third search space; and

the first downlink control channel decoding candidate comprises a first number of control channel elements (CCEs) in the second search space and a second number of CCEs in the third search space.

2. The method of claim 1, wherein the second number of PRBs comprises one of one, two, or four PRBs.

3. The method of claim 1, wherein the first number of PRBs comprises six PRBs.

4. The method of claim 1, wherein the first search space comprises a single downlink control channel decoding candidate.

5. The method of claim 1, wherein the first, second, or third downlink control channel decoding candidate is transmitted utilizing a set of subframes, and wherein the set of subframes comprises two or more subframes.

6. The method of claim 5, further comprising monitoring for the set of subframes, and wherein the set of subframes is determined based, at least in part, on an indication received from a network.

7. The method of claim 1, wherein the narrowband size is within a wider system bandwidth.

8. The method of claim 1, wherein the narrowband size is based on at least one of a category of the UE or a capability of the UE.

20. The method of claim 1, wherein the first number of CCEs comprises 8 CCEs and the second number of CCEs comprises 8 CCEs.

21. The method of claim 1, wherein monitoring for the first downlink control channel decoding candidate is performed according to a pre-defined index.

22. The method of claim 21, wherein the pre-defined index indicates one of:

the second search space followed by the third search space;

or

the third search space followed by the second search space.

23. The method of claim 21, wherein the pre-defined index is different for different UEs.

9. A method for wireless communications by a base station (BS), comprising:

identifying, within a subframe, a first search space spanning a first number of physical resource blocks (PRBs) that represents a narrowband size;

transmitting resources in the first search space corresponding to a first downlink control channel decoding candidate for a user equipment (UE) to monitor;

transmitting resources in a second search space corresponding to a second downlink control channel decoding candidate for the UE to monitor, wherein the second search space spans a second number of PRBs that is fewer than the first number of PRBs; and

transmitting resources in a third search space corresponding to a third downlink control channel decoding candidate for the UE to monitor, wherein the third search space spans a third number of PRBs that is fewer than the first number of PRBs and the second number of PRBs, wherein;

the first search space comprises a combination of the second search space and the third search space; and

the first downlink control channel decoding candidate comprises a first number of control channel elements (CCEs) in the second search space and a second number of CCEs in the third search space.

10. The method of claim 9, wherein the second number of PRBs comprises one, two, or four PRBs.

11. The method of claim 9, wherein the first number of PRBs comprises six PRBs.

12. The method of claim 9, further comprising transmitting different sets of downlink control channel decoding candidates within each of the first, second, and third search spaces.

13. The method of claim 9, wherein the first search space comprises a single downlink control channel decoding candidate.

14. The method of claim 9, wherein the resources corresponding to the first, second, or third downlink control channel decoding candidate comprise a set of subframes, and wherein the set of subframes comprises two or more subframes.

15. The method of claim 14, further comprising transmitting an indication indicating the set of subframes to monitor.

16. The method of claim 9, wherein the narrowband size is within a wider system bandwidth.

17. The method of claim 9, wherein the narrowband size is based on at least one of a category of the UE or a capability of the UE.

24. The method of claim 9, wherein the first number of CCEs comprises 8 CCEs and the second number of CCEs comprises 8 CCEs.

25. The method of claim 9, wherein the first downlink control channel decoding candidate is indexed according to a pre-defined index.

26. The method of claim 25, wherein the pre-defined index indicates one of:

the second search space followed by the third search space;

or

the third search space followed by the second search space.

27. The method of claim 25, wherein the pre-defined index is different for different UEs.

18. An apparatus for wireless communications by a user equipment (UE), comprising:

at least one processor;

memory coupled to the at least one processor, the memory comprising code executable by the at least one processor to cause the UE to;

identify, within a subframe, a first search space spanning a first number of physical resource blocks (PRBs) that represents a narrowband size;

monitor the first search space for a first downlink control channel candidate;

monitor a second search space spanning a second number of PRBs for a second downlink control channel decoding candidate, wherein the second number of PRBs is fewer than the first number of PRBs; and

monitor a third search space spanning a third number of PRBs for a third downlink control channel decoding candidate, wherein the third number of PRBs is fewer than the first number of PRBs and the second number of PRBs, wherein;

the first search space comprises a combination of the second search space and the third search space; and

the first downlink control channel decoding candidate comprises a first number of control channel elements (CCEs) in the second search space and a second number of CCEs in the third search space.

19. An apparatus for wireless communications by a base station (BS), comprising:

at least one processor;

memory coupled to the at least one processor, the memory comprising code executable by the at least one processor to cause the BS to;

identify, within a subframe, a first search space spanning a first number of physical resource blocks (PRBs) that represents a narrowband size;

transmit resources in the first search space corresponding to a first downlink control channel decoding candidate for a use equipment (UE) to monitor;

transmit resources in a second search space corresponding to a second downlink control channel decoding candidate for the UE to monitor, wherein the second search space spans a second number of PRBs that is fewer than the first number of PRBs; and

transmit resources in a third search space corresponding to a third downlink control channel decoding candidate for the UE to monitor, wherein the third search space spans a third number of PRBs that is fewer than the first number of PRBs and the second number of PRBs, wherein;

the first search space comprises a combination of the second search space and the third search space; and

the first downlink control channel decoding candidate comprises a first number of control channel elements (CCEs) in the second search space and a second number of CCEs in the third search space.

28. An apparatus for wireless communications by a user equipment (UE), comprising:

means for identifying, within a subframe, a first search space spanning a first number of physical resource blocks (PRBs) that represents a narrowband size;

means for monitoring the first search space for a first downlink control channel decoding candidate;

means for monitoring a second search space spanning a second number of PRBs for a second downlink control channel decoding candidate, wherein the second number of PRBs is fewer than the first number of PRBs; and

means for monitoring a third search space spanning a third number of PRBs for a third downlink control channel decoding candidate, wherein the third number of PRBs is fewer than the first number of PRBs and the second number of PRBs, wherein;

the first search space comprises a combination of the second search space and the third search space; and

the first downlink control channel decoding candidate comprises a first number of control channel elements (CCEs) in the second search space and a second number of CCEs in the third search space.

29. An apparatus for wireless communications by a base station (BS), comprising:

means for identifying, within a subframe, a first search space spanning a first number of physical resource blocks (PRBs) that represents a narrowband size;

means for transmitting resources in the first search space corresponding to a first downlink control channel decoding candidate for a user equipment (UE) to monitor;

means for transmitting resources in a second search space corresponding to a second downlink control channel decoding candidate for the UE to monitor, wherein the second search space spans a second number of PRBs that is fewer than the first number of PRBs; and

means for transmitting resources in a third search space corresponding to a third downlink control channel decoding candidate for the UE to monitor, wherein the third search space spans a third number of PRBs that is fewer than the first number of PRBs and the second number of PRBs, wherein;

the first search space comprises a combination of the second search space and the third search space; and

the first downlink control channel decoding candidate comprises a first number of control channel elements (CCEs) in the second search space and a second number of CCEs in the third search space.

30. A computer-readable medium for wireless communications by a user equipment (UE), the computer-readable medium comprising code executable by at least one processor to cause the UE to:

identify, within a subframe, a first search space spanning a first number of physical resource blocks (PRBs) that represents a narrowband size;

monitor the first search space for a first downlink control channel decoding candidate;

monitor a second search space spanning a second number of PRBs for a second downlink control channel decoding candidate, wherein the second number of PRBs is fewer than the first number of PRBs; and

monitor a third search space spanning a third number of PRBs for a third downlink control channel decoding candidate, wherein the third number of PRBs is fewer than the first number of PRBs and the second number of PRBs, wherein;

the first search space comprises a combination of the second search space and the third search space; and

the first downlink control channel decoding candidate comprises a first number of control channel elements (CCEs) in the second search space and a second number of CCEs in the third search space.

31. A computer-readable medium for wireless communications by a base station (BS), the computer-readable medium comprising code executable by at least one processor to cause the BS to:

identify, within a subframe, a first search space spanning a first number of physical resource blocks (PRBs) that represents a narrowband size;

transmit resources in the first search space corresponding to a first downlink control channel decoding candidate for a user equipment (UE) to monitor;

transmit resources in a second search space corresponding to a second downlink control channel decoding candidate for the UE to monitor, wherein the second search space spans a second number of PRBs that is fewer than the first number of PRBs; and

transmit resources in a third search space corresponding to a third downlink control channel decoding candidate for the UE to monitor, wherein the third search space spans a third number of PRBs that is fewer than the first number of PRBs and the second number of PRBs, wherein;

the first search space comprises a combination of the second search space and the third search space; and

the first downlink control channel decoding candidate comprises a first number of control channel elements (CCEs) in the second search space and a second number of CCEs in the third search space.