Method and device for monitoring downlink channels

Patent metadata

Field	Value
Publication number	US-9479407-B2
Application number	US-201314384343-A
Country	US
Kind code	B2
Filing date	Apr 5, 2013
Priority date	Apr 5, 2012
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

Disclosed are a method and a device for monitoring a downlink control channel in a wireless communication system. The method for monitoring a downlink control channel in a wireless communication system may comprise the steps of determining whether a common search space in a subframe exists in a physical downlink control channel (PDCCH) region or in an enhanced physical downlink control channel (ePDCCH) region; and when the common search space exists in the ePDCCH region, monitoring, in the ePDCCH region, a downlink control channel for hybrid automatic repeat request (HARQ) acknowledgement (ACK) or non-acknowledgement (NACK) information.

First claim

What is claimed is:

1. A method for monitoring a downlink control channel by a user equipment (UE) in a wireless communication system, the method comprising:
determining, by the UE, whether a common search space is present in a physical downlink control channel (PDCCH) region or an enhanced physical downlink control channel (ePDCCH) region in a subframe; and
monitoring, by the UE, when the common search space is present in the ePDCCH region, a downlink control channel for HARQ (hybrid automatic repeat request) ACK (acknowledgement)/NACK (non-acknowledgement) information in the ePDCCH region,
wherein the monitoring includes:
monitoring, by the UE, the ePDCCH based on a first candidate position in the common search space; and
monitoring, by the UE, the HARQ ACK/NACK based on a second candidate position in the common search space, and

wherein the first candidate position represents a start point of a resource region in which blind decoding is performed,
wherein the common search space is present at a fixed position in the PDCCH region or the ePDCCH region in all subframes,
wherein the PDCCH region is a region in which a PDCCH is monitored based on a cell-specific reference signal (CRS) in the subframe,
wherein the CRS is a reference signal created based on a cell identifier,
wherein the ePDCCH region is a region in which an ePDCCH is monitored based on a demodulation reference signal (DM-RS) in the subframe,
wherein the DM-RS is a reference signal created based on a value given by a base station, and
wherein the downlink control channel transports the HARQ ACK/NACK information for a plurality of UEs.

2. The method of claim 1 ,
wherein the monitoring of the downlink channel further includes:
monitoring, by the UE, the ePDCCH based on a first control channel element (CCE) aggregation level in the common search space; and
monitoring, by the UE, the HARQ ACK/NACK based on a second CCE aggregation level in the common search space, and
wherein the CCE aggregation level represents a unit of the resource region in which the blind decoding is performed.

3. The method of claim 1 , further comprising:
monitoring, when the common search space is present in the PDCCH region, the downlink control channel for the HARQ ACK/NACK information in the PDCCH region.

4. The method of claim 3 , further comprising:
determining whether the common search space of the PDCCH is present as a threshold value or more; and
measuring channel status information based on the CRS when the common search space of the PDCCH is present as the threshold value or more.

5. The method of claim 4 , further comprising:
measuring the channel status information based on the DM-RS when the common search space of the PDCCH is present as a value less than the threshold value.

6. A user equipment (UE) for monitoring a downlink control channel in a wireless communication system, the UE comprising:
a processor,
wherein the processor is configured to:
determine whether a common search space is present in a physical downlink control channel (PDCCH) region or an enhanced physical downlink control channel (ePDCCH) region in a subframe, and
monitor, when the common search space is present in the ePDCCH region, a downlink control channel for HARQ (hybrid automatic repeat request) ACK (acknowledgement)/NACK (non-acknowledgement) information in the ePDCCH region by monitoring the ePDCCH based on a first candidate position in the common search space, and monitoring the HARQ ACK/NACK based on a second candidate position in the common search space, and

wherein the first candidate position represents a start point of a resource region in which blind decoding is performed,
wherein the common search space is present at a fixed position in the PDCCH region or the ePDCCH region in all subframes,
wherein the PDCCH region is a region in which a PDCCH is monitored based on a cell-specific reference signal (CRS) in the subframe,
wherein the CRS is a reference signal created based on a cell identifier,
wherein the ePDCCH region is a region in which an ePDCCH is monitored based on a demodulation reference signal (DM-RS) in the subframe,
wherein the DM-RS is a reference signal created based on a value given by a base station, and
wherein the downlink control channel transports the HARQ ACK/NACK information for a plurality of UEs.

7. The UE of claim 6 ,
wherein the processor is further configured to monitor the downlink control channel by monitoring the ePDCCH based on a first control channel element (CCE) aggregation level in the common search space, and monitoring HARQ ACK/NACK based on a second CCE aggregation level in the common search space, and
wherein the CCE aggregation level represents a unit of the resource region in which the blind decoding is performed.

8. The UE of claim 6 ,
wherein the processor is further configured to monitor the downlink control channel for the HARQ ACK/NACK information in the PDCCH region when the common search space is present in the PDCCH region.

9. The UE of claim 8 ,
wherein the processor is further configured to determine whether the common search space of the PDCCH is present as a threshold value or more and measure a channel status information based on the CRS when the common search space of the PDCCH is present as the threshold value or more.

10. The UE of claim 9 ,
wherein the processor is further configured to measure the channel status information based on the DM-RS when the common search space of the PDCCH is present as a value less than the threshold value.

Assignees

• Lg Electronics Inc

Inventors

• Kim Hakseong
• Seo Hanbyul

Classifications

• H04L43/08 Primary

  Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters · CPC title

• H04L1/1607 Primary

  Details of the supervisory signal · CPC title

• H04L5/0073

  Allocation arrangements that take into account other cell interferences · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04L5/0055

  Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861) · CPC title