Abbreviated blind detection in wireless communication systems including LTE

Patent metadata

Field	Value
Publication number	US-9681256-B2
Application number	US-201414214739-A
Country	US
Kind code	B2
Filing date	Mar 15, 2014
Priority date	Mar 15, 2014
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A method and apparatus are provided for abbreviating the blind decoding process performed by a UE, such as an LTE UE, on control channel data such as PDCCH data of PRB pairs of a set of PRB pairs transmitted concurrently within a subframe. In some embodiments, only a prioritized portion of the PDCCH data is decoded, thereby expediting blind decoding. In some embodiments, a reduced number of encoding options for the PDCCH data is used, and blind decoding is expedited by considering only such options as possibilities. When blind decoding of the PDCCH data is completed before the end of the subframe, this may be used to identify and discard corresponding PDSCH data which is irrelevant to the UE. The prioritized portion may be adjusted as needed to include the CSS so as not to miss certain critical data.

First claim

We claim:

1. A method of supporting downlink communication in an LTE wireless communication system, comprising:
wirelessly receiving a set of Physical Resource Block (PRB) pairs at a UE, each PRB pair of the set of PRB pairs comprising PDCCH data followed by PDSCH data, each PRB pair of the set of PRB pairs having been transmitted concurrently within a subframe;
concurrently with receipt of said set of PRB pairs, performing blind decoding by the UE of a prioritized portion of the PDCCH data of PRB pairs of the set of PRB pairs, wherein said blind decoding is completed prior to reception of an end of the subframe; and
for at least some PRB pairs for which the decoded PDCCH data thereof is indicative that the PDSCH data of the same subframe is devoid of data intended for the UE, refraining, by the UE, from one or both of buffering and decoding of at least some of said PDSCH data.

2. The method according to claim 1 , further comprising determining whether the UE is in connected mode, wherein performing said blind decoding of the PDCCH data of each subframe when the UE is in connected mode comprises:
selecting the prioritized portion of the PDCCH data as a strict subset of: a User Search Space (USS) portion of the PDCCH data in combination with a Common Search Space (CSS) portion of the PDCCH data; and
performing blind decoding of only the prioritized portion.

3. The method according to claim 2 , wherein the prioritized portion corresponds to either the entire USS portion or the entire CSS portion.

4. The method according to claim 2 , wherein the prioritized portion is periodically selected to correspond to the entire CSS portion, thereby configuring the UE for receipt of predetermined information scheduled via the CSS portion.

5. The method according to claim 4 , wherein the predetermined information comprises one or more of: P-RNTI and SIB data.

6. The method according to claim 4 , further comprising transmitting a notification from the UE to a eNB serving the UE, the notification indicative of the subframe during which the prioritized portion is periodically selected to correspond to the entire CSS portion, and refraining, by the eNB, from scheduling transmissions to the UE via the USS portion which is received at the UE during said subframe.

7. The method according to claim 2 , further comprising communicating to the UE, prior to the subframe, that a P-RNTI message will appear in the subframe, and monitoring, by the UE, the CSS portion during the subframe in order to facilitate reception of the P-RNTI message.

8. The method according to claim 2 , further comprising communicating via the USS, that SIB information has been updated, said communication being triggered by the eNB transmitting both a P-RNTI message and USS data for receipt by the UE in the subframe.

9. The method according to claim 1 , further comprising transmitting a request, from the UE to a eNB serving the UE, that the eNB transmit SIB refresh information during a subframe or subframe window indicated in the request, and transmitting, by the eNB, the requested SIB update information during the indicated subframe or subframe window.

10. The method according to claim 1 , further comprising transmitting, from a eNB serving the UE and upon request by the UE, SIB information to the UE, the SIB information scheduled via a USS portion of the PDCCH.

11. The method according to claim 1 , wherein the UE belongs to a subclass of UEs within a larger population of UEs, wherein the subclass of UEs exhibits relatively reduced capability in terms of one or both of: computational power and buffer memory size.

12. The method according to claim 11 , further comprising defining a restricted SI window size for transmission of one or more SIBs other than SIB1 by an eNB for receipt by the UE, wherein the restricted SI window size is smaller than the corresponding default SI window size defined generally for the larger population of UEs.

13. The method according to claim 11 , further comprising pre-defining a SIB update window known a priori to the UE and an eNB and transmitting SIB updates during said window, wherein the SIB update window is specific to the UE.

14. The method according to claim 1 , wherein the UE is configured to acquire P-RNTI data by decoding CSS at a period corresponding to a longest DRX cycle supported by the LTE wireless communication system, wherein the eNB is configured to transmit P-RNTI data periodically at times related to a DRX cycle of the UE, said times being selected such that said P-RNTI data is transmitted via subframes during which the UE is anticipated to be decoding CSS in accordance with the DRX cycle.

15. The method according to claim 1 , further comprising defining a SIB update time window for the UE, and upon expiry of SIB information, refreshing, by the UE, SIB information at the earlier of: expiry of the SIB update time window; and shifting of the UE from connected mode to idle mode.

16. The method of claim 1 ,
wherein at least a portion of the PDCCH data is encoded utilizing a reduced set of encoding options relative to a full set of encoding options available for use in communication with relatively higher capability UEs; and
wherein said blind decoding is limited to a reduced set of decoding options which is complementary to the reduced set of encoding options.

17. The method according to claim 16 , wherein the portion of the PDCCH data is a User Search Space (USS) portion of the PDCCH data.

18. The method according to claim 16 , wherein said reduced set of encoding options is defined by a reduced set of candidates for the User Search Space (USS), relative to a full set of candidates for the USS available for use in communication with the relatively higher capability UEs.

19. The method according to claim 16 , wherein said reduced set of encoding options is defined by a reduced set of DCI formats for the User Search Space (USS), relative to a full set of DCI formats for the USS available for use in communication with the relatively higher capability UEs.

20. The method according to claim 1 , further comprising:
notifying an eNB, by the UE via wireless communication, of one or more subframes during which the UE will be unreceptive of data scheduled via USS due to lack of monitoring of USS portions of PDCCH data of said one or more subframes; and
refraining, by the eNB, from scheduling data transmission via USS during the one or more subframes.

21. A wireless terminal device configured for communication in an LTE wireless communication system, comprising:
a receiver configured to wirelessly receive, from a base station, a set of Physical Resource Block (PRB) pairs, each PRB pair of the set of PRB pairs comprising PDCCH data followed by PDSCH data, each PRB pair of the set of PRB pairs having been transmitted concurrently within a subframe;
a prioritization filter configured to select a prioritized portion of the PDCCH data of PRB pairs of the set of PRB pairs;
a blind decoder configured, concurrently with receipt of said set of PRB pairs, to perform blind decoding of the prioritized portion of the PDCCH data of PRB pairs of the set of PRB pairs, wherein said blind decoding is completed prior to reception of an end of the subframe; and
a buffer controller configured, for at least some PRB pairs for which the decoded PDCCH data thereof is indicative that the PDSCH data of the same subframe is devoid of data intended for the UE, to inhibit one or both of buffering and decoding of at least some of said PDSCH data.

Assignees

• Sierra Wireless Inc

Inventors

• Vos Gustav Gerald
• Mysore Balasubramanya Naveen
• Lampe Lutz Hans-Joachim
• Bennett Steven John

Classifications

• H04L5/0007

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title

• H04W4/70 Primary

  Services for machine-to-machine communication [M2M] or machine type communication [MTC] · CPC title

• H04L5/0053

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title

• H04L5/00

  Arrangements affording multiple use of the transmission path · CPC title

• H04W4/005 Primary

  Electricity · mapped topic