Control signaling optimization for LTE communications

• US 9,445,429 B2
• Filed: 09/30/2014
• Issued: 09/13/2016
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Tabet, Tarik, Majjigi, Vinay R., Mucke, Christian W., Mujtaba, Syed A.
• Primary Examiner(s): Abelson, Ronald B
• Application Number:
  US14/502,507
• Publication Number:
  US 20150092647A1
• Time in Patent Office: 714 Days
• Field of Search: 370/311
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 28/0221 power availability or consumption
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The disclosure describes procedures for including downlink control information (DCI) within a physical downlink shared channel (PDSCH) communication to reduce power consumption for a user equipment (UE) operating in a Long Term Evolution (LTE) network. A network apparatus can be configured to identify an expected DCI change for the UE, determine whether an LTE subframe location for the DCI change is known, generate either a general or a specific DCI change indicator, and send the corresponding DCI change indicator to the UE on the PDSCH. The specific DCI change indicator can include a bitmap identifying a particular upcoming LTE subframe where the UE is required to decode the PDCCH for DCI, and the general DCI change indicator can include a bit flag identifying a time associated with one or more upcoming LTE subframes when the UE should decode the PDCCH for DCI.

Claims

1. A method for allocating network resources for a user equipment (UE) communicating within a Long Term Evolution (LTE) network, the method comprising:

at a network apparatus;

identifying an expected downlink control information (DCI) change for the UE;

determining whether an LTE subframe location for the DCI change is known;

in response to determining, generating a DCI change indicator; and

sending the DCI change indicator to the UE on a physical downlink shared channel (PDSCH) to instruct the UE where to decode a physical downlink control channel (PDCCH) for a DCI,

wherein the DCI change indicator comprises;

a general DCI change indicator when the LTE subframe location for the DCI change is not known, or

a precise DCI change indicator when the LTE subframe location for the DCI change is known.

2. The method of claim 1, further comprising:

determining that the LTE subframe location for the DCI change is not known; and

in response to determining, generating the general DCI change indicator for the UE.

3. The method of claim 2, wherein the general DCI change indicator is sent to the UE as a bit flag identifying a time associated with one or more upcoming LTE subframes when the UE is required to decode the PDCCH for the DCI.

4. The method of claim 2, wherein the general DCI change indicator is sent to the UE as a bit flag including an open indication that requires the UE to decode the PDCCH at least until the DCI is acquired by the UE.

5. The method of claim 1, further comprising:

determining that the LTE subframe location for the DCI change is known; and

in response to determining, generating precise DCI change indicator for the UE.

6. The method of claim 5, wherein the precise DCI change indicator is sent to the UE as a bitmap identifying a particular upcoming LTE subframe where the UE is required to decode the PDCCH for the DCI.

7. The method of claim 1, wherein:

the DCI change indicator is sent to the UE within a payload portion of a PDSCH communication; and

the DCI corresponds to a voice over LTE (VoLTE) data or a best effort (BE) data network allocation change for the UE.

8. The method of claim 1, wherein the DCI change indicator identifies one or more upcoming LTE subframes that occur during an ON duration of a connected mode discontinuous reception (C-DRX) cycle of the UE.

9. A mobile device, comprising:

at least one transceiver configurable to communicate via a long term evolution (LTE) network;

one or more processors; and

a storage device storing executable instructions that, when executed by the one or more processors, cause the mobile device to;

decode a physical downlink shared channel (PDSCH);

acquire a downlink control information (DCI) change indicator from a payload portion of a PDSCH communication; and

decode a physical downlink control channel (PDCCH) for a DCI based on the DCI change indicator,

wherein the DCI change indicator indicates when the mobile device is required to decode the PDCCH for the DCI and comprises;

a general DCI change indicator that (i) identifies a time associated with one or more upcoming LTE subframes or (ii) includes an open indication to decode the DPCCH at least until the DCI is acquired, or

a specific DCI change indicator that identifies a particular upcoming LTE subframe.

10. The mobile device of claim 9, wherein the DCI change indicator comprises the general DCI change indicator that identifies the time associated with the one or more upcoming LTE subframes when the mobile device is required to decode the PDCCH for the DCI.

11. The mobile device of claim 9, wherein the DCI change indicator comprises the general DCI change indicator that includes the open indication requiring the mobile device to decode the PDCCH at least until the DCI is acquired by the mobile device.

12. The mobile device of claim 9, wherein the DCI change indicator comprises the specific DCI change indicator that includes a bitmap identifying the particular upcoming LTE subframe where the mobile device is required to decode the PDCCH for the DCI.

13. The mobile device of claim 9, wherein:

there are one or more reserved LTE subframes that occur during an ON duration of a connected mode discontinuous reception (C-DRX) cycle of the mobile device requiring the mobile device to decode the PDCCH without a DCI change indication;

the DCI change indicator is valid for multiple ON durations of the C-DRX cycle of the mobile device; and

the DCI decoded from the PDCCH based on the DCI change indicator is valid for multiple ON durations of the C-DRX cycle of the mobile device.

14. The mobile device of claim 9, further comprising a PDCCH timer,

wherein execution of the executable instructions further causes the mobile device to start the PDCCH timer to designate a do-not-decode period that prevents the mobile device from decoding the PDCCH during the do-not-decode period.

15. The mobile device of claim 14, wherein execution of the executable instructions further causes the mobile device to:

determine when the PDCCH timer has expired; and

in response to determining, decode the PDCCH until the PDCCH timer is restarted.

16. The mobile device of claim 14, wherein execution of the executable instructions further causes the mobile device to:

receive a new DCI change indicator on the PDSCH during the do-not-decode period; and

in response to receiving the new DCI change indicator, decode the PDCCH during the do-not-decode period in accordance with the DCI change indicator,

wherein the PDCCH timer is specified in terms of a number of connected mode discontinuous reception (C-DRX) cycles for the mobile device.

17. A non-transitory computer-readable medium storing executable instructions that, when executed by one or more processors of a network apparatus, cause the network apparatus to:

identify an expected downlink control information (DCI) change for a mobile device;

determine whether an LTE subframe location for the DCI change is known;

in response to determining, generate a DCI change indicator; and

send the DCI change indicator to the mobile device on a physical downlink shared channel (PDSCH) to instruct the mobile device where to decode a physical downlink control channel (PDCCH) for a DCI,

wherein the DCI change indicator comprises;

a general DCI change indicator when the LTE subframe location for the DCI change is not known, or

a precise DCI change indicator when the LTE subframe location for the DCI change is known.

18. The non-transitory computer-readable medium of claim 17, wherein:

the DCI change indicator comprises the general DCI change indicator for the mobile device; and

the general DCI change indicator is sent to the mobile device as a bit flag that;

i. identifies a time associated with one or more upcoming LTE subframes when the mobile device is required to decode the PDCCH for the DCI;

or

ii. includes an open indication requiring the mobile device to decode the PDCCH at least until the DCI has been acquired by the mobile device.

19. The non-transitory computer-readable medium of claim 17, wherein:

the DCI change indicator comprises the precise DCI change indicator for the mobile device; and

the precise DCI change indicator is sent to the mobile device as a bitmap that identifies a particular upcoming LTE subframe where the mobile device is required to decode the PDCCH for the DCI.

20. The non-transitory computer-readable medium of claim 17, wherein the DCI change indicator identifies one or more upcoming LTE subframes that occur during an ON duration of a connected mode discontinuous reception (C-DRX) cycle of the mobile device where PDCCH needs to be decoded.