Method and device for monitoring downlink channels

• US 9,479,407 B2
• Filed: 04/05/2013
• Issued: 10/25/2016
• Est. Priority Date: 04/05/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Hakseong, Seo, Hanbyul
• Primary Examiner(s): Nguyen, Brian D
• Assistant Examiner(s): NGUYEN, TOAN D
• Application Number:
  US14/384,343
• Publication Number:
  US 20150043355A1
• Time in Patent Office: 1,299 Days
• US Class Current: 1/1
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 43/08 Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005

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.

Claims

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.