TECHNIQUES FOR IMPROVED CONTROL CHANNELS

• US 20180098307A1
• Filed: 07/28/2017
• Published: 04/05/2018
• Est. Priority Date: 10/03/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Yang, Yang, Ang, Peter Pui Lok, Chen, Wanshi, Lee, Heechoon, Jiang, Jing, Ji, Tingfang, Luo, Tao
• Granted Patent: US 11,825,482 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 25/024 channel estimation algorithms
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Methods, systems, and devices for wireless communication are described. A method may include receiving a control transmission from a base station, identifying a control channel search space organized according to a nested structure, the control channel search space including a plurality of control channel candidates associated with one or more control channel elements (CCEs) and an aggregation level, and searching the received control transmission to identify a control channel for the UE using the plurality of control channel candidates. Another method may include determining whether to reorder resource element group (REG) indices for a received control channel transmission based, at least in part, on a transmission mode associated with the control channel transmission. Another method may include decoding a received control channel transmission, where the downlink control information (DCI) formats may be constrained to an integer multiple of a predetermined base number of bits N.

Claims

1. A method for wireless communication, comprising:

receiving a control transmission from a base station;

identifying a control channel search space that is organized according to a nested structure, the control channel search space including a plurality of control channel candidates, wherein each of the plurality of control channel candidates is associated with one or more control channel elements (CCEs) and an aggregation level; and

searching the received control transmission to identify a control channel for the UE using the plurality of control channel candidates.

2. The method of claim 1, wherein a lower aggregation level search space includes one or more CCEs that are a subset of a higher aggregation level search space.

3. The method of claim 1, wherein a higher aggregation level search space comprises a sum of a plurality of lower aggregation level search spaces.

4. The method of claim 3, wherein the plurality of lower aggregation level search spaces comprise one or more search spaces associated with a first aggregation level and one or more search spaces associated with a second aggregation level.

5. The method of claim 3, further comprising:

decoding control channel candidates associated with the plurality of lower aggregation level search spaces;

generating log-likelihood ratio (LLR) information during the decoding; and

decoding control channel candidates associated with the higher aggregation level search space based at least in part on the generated LLR information.

6. The method of claim 1, wherein the control channel search space is based at least in part on whether the control transmission is configured for uplink transmission or downlink transmission.

7. A method for wireless communication, comprising:

receiving a control channel transmission from a base station that includes a plurality of resource element groups (REGs) organized into one or more control channel elements;

identifying REG indices associated with the plurality of REGs;

determining whether to reorder the REG indices based at least in part on a transmission mode associated with the control channel transmission; and

decoding the control channel transmission based at least in part on the plurality of REG indices to generate a control channel.

8. The method of claim 7, further comprising:

reordering the indices associated with the REGs based at least in part on a bit-reversal de-interleaving procedure.

9. The method of claim 7, further comprising:

reordering the indices associated with the REGs, wherein the transmission mode associated with the received control channel transmission comprises broadcasting or multicasting.

10. The method of claim 9, further comprising:

performing wide-band channel estimation independent of the reordering.

11. The method of claim 7, further comprising:

refraining from reordering the indices associated with the REGs, wherein the identified transmission mode for the received control channel transmission comprises beamformed unicasting.

12. The method of claim 11, further comprising:

refraining from performing wide-band channel estimation.

13. A method for wireless communication, comprising:

receiving a control channel transmission from a base station;

identifying a plurality of downlink control information (DCI) formats, each DCI format having a bit length that is an integer multiple of a predetermined base number of bits; and

decoding the control channel transmission based at least in part on the identified plurality of DCI formats to obtain DCI for the UE.

14. The method of claim 13, wherein the predetermined base number of bits associated with DCI formats for uplink data is different that a second predetermined base number of bits associated with DCI formats for downlink data.

15. The method of claim 13, further comprising:

receiving, from the base station, an indicator of a bit length for the DCI for the UE in a radio resource control message or in a control region of a downlink subframe.

16. The method of claim 13, wherein:

one or more DCI formats of the plurality of DCI formats comprise a first DCI format portion and a second DCI format portion;

decoding the control channel transmission comprises decoding a first portion of the control channel transmission based at least in part on the first DCI format portion to obtain an indicator of a bit length of the second DCI portion format and to obtain a first portion of the DCI; and

the method further comprising decoding a second portion of the control channel transmission based at least in part on the obtained indicator to obtain a second portion of the DCI.

17. The method of claim 13, further comprising:

identifying that the UE is configured with a grant associated with a number of transmission time intervals (TTIs), wherein a bit length of the obtained DCI for the UE is based at least in part on the number of TTIs.

18. The method of claim 13, further comprising:

identifying that the UE is configured with a grant associated with a number of component carriers (CCs), wherein a bit length of the obtained DCI for the UE is based at least in part on the number of CCs.

19. The method of claim 13, wherein identifying the plurality of DCI formats comprises:

identifying the bit length based at least in part on radio resource control (RRC) signaling, a preamble, mini-control signaling, or some combination thereof.

20. An apparatus for wireless communication, comprising:

a processor; and

memory coupled to the processor, wherein the processor is configured to;

receive a control channel transmission from a base station;

identify a plurality of downlink control information (DCI) formats, each DCI format having a bit length that is an integer multiple of a predetermined base number of bits; and

decode the control channel transmission based at least in part on the identified plurality of DCI formats to obtain DCI for the UE.

21. The apparatus of claim 20, wherein the predetermined base number of bits associated with DCI formats for uplink data is different that a second predetermined base number of bits associated with DCI formats for downlink data.

22. The apparatus of claim 20, wherein the processor is further configured to:

receive, from the base station, an indicator of a bit length for the DCI for the UE in a radio resource control message or in a control region of a downlink subframe.

23. The apparatus of claim 20, wherein:

one or more DCI formats of the plurality of DCI formats comprise a first DCI format portion and a second DCI format portion;

the processor is configured to decode the control channel transmission comprises the processor is configured to decode a first portion of the control channel transmission based at least in part on the first DCI format portion to obtain an indicator of a bit length of the second DCI portion format and to obtain a first portion of the DCI; and

the processor is further configured to decode a second portion of the control channel transmission based at least in part on the obtained indicator to obtain a second portion of the DCI.

24. The apparatus of claim 20, wherein the processor is further configured to:

identify that the UE is configured with a grant associated with a number of transmission time intervals (TTIs), wherein a bit length of the obtained DCI for the UE is based at least in part on the number of TTIs.

25. The apparatus of claim 20, wherein the processor is further configured to:

identify that the UE is configured with a grant associated with a number of component carriers (CCs), wherein a bit length of the obtained DCI for the UE is based at least in part on the number of CCs.

26. The apparatus of claim 20, wherein the processor is configured to identify the plurality of DCI formats by being configured to:

identify the bit length based at least in part on radio resource control (RRC) signaling, a preamble, mini-control signaling, or some combination thereof.