Techniques for improved control channels

Patent metadata

Field	Value
Publication number	US-2018098307-A1
Application number	US-201715663154-A
Country	US
Kind code	A1
Filing date	Jul 28, 2017
Priority date	Oct 3, 2016
Publication date	Apr 5, 2018
Grant date	—

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.

First claim

What is claimed is:

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

Assignees

• Qualcomm Inc

Inventors

• Yang Yang
• Ang Peter Pui Lok
• Chen Wanshi
• Lee Heechoon
• Jiang Jing
• Ji Tingfang
• Luo Tao

Classifications

• H04W72/23 Primary

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W88/02

  Terminal devices · CPC title

• H04L5/0094

  Indication of how sub-channels of the path are allocated · CPC title

• H04W76/27

  Transitions between radio resource control [RRC] states · CPC title

• H04L25/024

  channel estimation algorithms · CPC title