Method for search space configuration of enhanced physical downlink control channel

• US 9,681,436 B2
• Filed: 08/10/2016
• Issued: 06/13/2017
• Est. Priority Date: 03/21/2012
• Status: Active Grant

• Current Assignee: HFI Innovation, Inc. (MediaTek, Inc.)
• Original Assignee: MediaTek, Inc.
• Inventors: Liao, Pei-Kai, Zhuang, Xiangyang
• Primary Examiner(s): Nguyen, Brian D
• Assistant Examiner(s): NGUYEN, TOAN D
• Application Number:
  US15/233,099
• Publication Number:
  US 20160353421A1
• Time in Patent Office: 307 Days
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A method to allocate physical radio resources for both distributed and localized transmission schemes of ePDCCH and configure common and UE-specific search space for UE is provided. In one embodiment, a UE receives a first high-layer information to determine a first set of PRBs. The UE determines a first set of candidate ePDCCHs within the first set of PRBs, wherein one or more candidate ePDCCHs potentially carries DCI intended for the UE. The UE then decodes the first set of candidate ePDCCHs to obtain the DCI intended for the UE. Similar steps are performed for a second set of candidate ePDCCHs potentially carrying DCI intended for the UE. The allocated radio resources of the candidate ePDCCHs may be distributed or localized and constitute either common or UE-specific search space. Blind decoding complexity is reduced.

Claims

1. A method comprising:

receiving a first high-layer information from a base station by a user equipment (UE) to determine a first set of physical resource blocks (PRBs);

determining a first set of candidate enhanced physical downlink control channel (ePDCCHs) within the first set of PRBs, wherein one or a plurality of candidate ePDCCHs carries downlink control information intended for the UE;

decoding the first set of candidate ePDCCHs to obtain the downlink control information intended for the UE;

receiving a second high-layer information from the base station by the UE to determine a second set of PRBs, wherein the second high-layer information is different from the first high-layer information;

determining a second set of candidate ePDCCHs within the second set of PRBs, wherein one or a plurality of candidate ePDCCHs carries the downlink control information intended for the UE; and

decoding the second set of candidate ePDCCHs to obtain the downlink control information intended for the UE.

2. The method of claim 1, wherein the first set of candidate ePDCCHs is of distributed type, wherein radio resources employed by distributed ePDCCHs spread across multiple non-contiguous PRBs.

3. The method of claim 2, wherein the first set of candidate ePDCCHs constitutes a common search space intended for a plurality of UEs in a cell.

4. The method of claim 2, wherein the first set of candidate ePDCCHs constitutes a UE-specific search space intended for the specific UE only.

5. The method of claim 1, wherein the first set of candidate ePDCCHs is of localized type, wherein radio resources employed by localized ePDCCHs are within one PRB or contiguous PRBs.

6. The method of claim 5, wherein the first set of candidate ePDCCHs constitutes a UE-specific search space intended for the specific UE only.

7. The method of claim 1, wherein the second set of candidate ePDCCHs is of distributed type, wherein radio resources employed by distributed ePDCCHs spread across multiple non-contiguous PRBs.

8. The method of claim 1, wherein the second set of candidate ePDCCHs is of localized type, wherein radio resources employed by localized ePDCCHs are within one PRB or contiguous PRBs.

9. The method of claim 1, wherein the UE decodes the first set of ePDCCHs of distributed type for UE-specific search space in a first subframe applying a diversity transmission scheme, and wherein the UE decodes the second set of ePDCCHs of localized type for UE-specific search space in a second subframe applying a beamforming transmission scheme.

10. A method comprising:

transmitting a first high-layer information indicative of a first set of physical resource blocks (PRBs) from a base station to each UE, wherein a first set of candidate enhanced physical downlink control channels (ePDCCHs) are allocated within the first set of PRBs;

mapping physical resources in each candidate ePDCCHs to a set of logical enhanced control channel elements (eCCEs) for each UE, wherein one or a plurality of candidate ePDCCHs carries downlink control information (DCI);

encoding the downlink control information over a corresponding set of logical eCCEs to be transmitted to a UE if there is DCI intended for the UE;

transmitting a second high-layer information indicative of a second set of PRBs from the base station to each UE, wherein a second set of ePDCCHs are allocated within the second set of PRBs, and wherein the second high-layer information is different from the first high-layer information;

mapping physical resources in each candidate ePDCCHs to a set of eCCEs for each UE, wherein one or a plurality of candidate ePDCCHs carries downlink control information (DCI); and

encoding the downlink control information over a corresponding set of logical eCCEs to be transmitted to the UE if there is DCI intended for the UE.

11. The method of claim 10, wherein the first set of candidate ePDCCHs is of distributed type, wherein radio resources employed by distributed ePDCCHs spread across multiple non-contiguous PRBs.

12. The method of claim 11, wherein the first set of candidate ePDCCHs constitutes a common search space associated with predefined logical eCCEs intended for a plurality of UEs in a cell.

13. The method of claim 11, wherein the first set of candidate ePDCCHs constitutes a UE-specific search space associated with predefined logical eCCEs intended for a specific UE only.

14. The method of claim 10, wherein the first set of candidate ePDCCHs is of localized type, wherein radio resources employed by localized ePDCCHs are within one PRB or contiguous PRBs.

15. The method of claim 14, wherein the first set of candidate ePDCCHs constitutes a UE-specific search space intended for the specific UE only.

16. The method of claim 10, wherein the second set of candidate ePDCCHs is of distributed type, wherein radio resources employed by distributed ePDCCHs spread across multiple non-contiguous PRBs.

17. The method of claim 10, wherein the second set of candidate ePDCCHs is of localized type, wherein radio resources employed by localized ePDCCHs are within one PRB or contiguous PRBs.

18. The method of claim 10, wherein the base station transmits the first set of ePDCCHs of distributed type for UE-specific search space to a UE in a first subframe, and wherein the base station transmits the second set of ePDCCHs of localized type for UE-specific search space to the same UE in a second subframe.