Method and apparatus for configuring search space of a downlink control channel
A method for configuring a search space of a downlink control channel is provided. The method includes determining the parameters for Enhanced Physical Downlink Control Channel (E-PDCCH) candidates of each aggregate level according to the number of Resource Elements (RE) in a subframe and/or the number of bits of Downlink Control Information (DCI) formats, when the parameters for E-PDCCH candidates of E-PDCCH search space is configured, determining, by a User Equipment (UE), the parameters for E-PDCCH candidates according to a current downlink subframe and a detected DCI format, and detecting blindly, by the UE, the E-PDCCH candidates in the E-PDCCH search space corresponding to the parameters for E-PDCCH candidates. The present invention also provides a UE and a base station. Application of the present invention can improve the flexibility of the base station scheduling, and reduce the possibility that the E-PDCCHs of different UEs block each other.
1. A method by a terminal in a wireless communication system, the method comprising:
identifying a downlink control information (DCI) format for an enhanced physical downlink control channel (E-PDCCH);
identifying a quantity of E-PDCCH candidates of each of aggregation levels based on whether the identified DCI format is included in a predefined group of DCI format; and
receiving downlink control information by monitoring the E-PDCCH candidates in an E-PDCCH search space,
wherein the E-PDCCH search space is determined based on the identified quantity of E-PDCCH candidates.
2. The method of claim 1 , wherein the quantity of E-PDCCH candidates is identified based on the identified DCI format and a quantity of resource elements (REs) in a physical resource block (PRB) pair for the E-PDCCH.
3. The method of claim 1 , further comprising:
identifying whether the DCI format is included in a first group of DCI format or a second group of DCI format,
wherein a number of bits of control information associated with the first group of DCI format is more than a number of bits of control information associated with the second group of DCI format.
4. The method of claim 1 , wherein a number of bits of control information associated with each of DCI formats is different from each other.
5. The method of claim 2 , wherein the quantity of REs in the PRB pair is calculated based on a quantity of REs for a common reference signal (CRS) and a channel state information reference signal (CSI-RS) in the PRB pair configured for the E-PDCCH.
6. The method of claim 1 , further comprising:
receiving information indicating whether the terminal monitors the E-PDCCH via a higher layer signaling.
7. The method of claim 2 , wherein the quantity of E-PDCCH candidates is identified based on a downlink subframe type, the quantity of REs, and the DCI format.
8. A terminal in a wireless communication system, the terminal comprising:
a transceiver configured to transmit and receive a signal; and
a controller configured to:
identify a downlink control information (DCI) format for an enhanced physical downlink control channel (E-PDCCH),
identify a quantity of E-PDCCH candidates of each of aggregation levels based on whether the identified DCI format is included in a predefined group of DCI format, and
receive downlink control information by monitoring the E-PDCCH candidates in an E-PDCCH search space,
wherein the E-PDCCH search space is determined based on the identified quantity of E-PDCCH candidates.
9. The terminal of claim 8 , wherein the quantity of E-PDCCH candidates is identified based on the identified DCI format and a quantity of resource elements (REs) in a physical resource block (PRB) pair for the E-PDCCH.
10. The terminal of claim 8 ,
wherein the controller is further configured to identify whether the DCI format is included in a first group of DCI format or a second group of DCI format, and
wherein a number of bits of control information associated with the first group of DCI format is more than a number of bits of control information associated with the second group of DCI format.
11. The terminal of claim 8 , wherein a number of bits of control information associated with each of DCI formats is different from each other.
12. The terminal of claim 9 , wherein the quantity of REs in the PRB pair is calculated based on a quantity of REs for a common reference signal (CRS) and a channel state information reference signal (CSI-RS) in the PRB pair configured for the E-PDCCH.
13. The terminal of claim 8 , wherein the controller is further configured to receive information indicating whether the terminal monitors the E-PDCCH via a higher layer signaling.
14. The terminal of claim 9 , wherein the quantity of E-PDCCH candidates is identified based on a downlink subframe type, the quantity of REs, and the DCI format.
15. A method by a base station in a wireless communication system, the method comprising:
identifying a downlink control information (DCI) format for an enhanced physical downlink control channel (E-PDCCH);
identifying a quantity of E-PDCCH candidates of each of aggregation levels based on whether the identified DCI format is included in a predefined group of DCI format;
selecting the E-PDCCH candidate in an E-PDCCH search space that is determined based on the quantity of E-PDCCH candidates; and
transmitting the E-PDCCH using resources corresponding to the selected E-PDCCH candidate.
16. The method of claim 15 , wherein the quantity of E-PDCCH candidates is identified based on the identified DCI format and a quantity of resource elements (REs) in a physical resource block (PRB) pair for the E-PDCCH.
17. The method of claim 15 , further comprising:
identifying whether the DCI format is included in a first group of DCI format or a second group of DCI format,
wherein a number of bits of control information associated with the first group of DCI format is more than a number of bits of control information associated with the second group of DCI format.
18. The method of claim 15 , wherein a number of bits of control information associated with each of DCI formats is different from each other.
19. The method of claim 16 , wherein the quantity of REs in the PRB pair is calculated based on a quantity of REs for a common reference signal (CRS) and a channel state information reference signal (CSI-RS) in the PRB pair configured for the E-PDCCH.
20. The method of claim 15 , further comprising:
transmitting information indicating whether the terminal monitors the E-PDCCH via a higher layer signaling.
21. The method of claim 16 , wherein the quantity of E-PDCCH candidates is identified based on a downlink subframe type, the quantity of REs, and the DCI format.
22. A base station in a wireless communication system, the base station comprising:
a controller configured to transmit and receive a signal; and
a controller configured to:
identify a downlink control information (DCI) format for an enhanced physical downlink control channel (E-PDCCH),
identify a quantity of E-PDCCH candidates of each of aggregation levels based on whether the identified DCI format is included in a predefined group of DCI format,
select the E-PDCCH candidate in an E-PDCCH search space that is determined based on the quantity of E-PDCCH candidates, and
transmit the E-PDCCH using resources corresponding to the selected E-PDCCH candidate.
23. The base station of claim 22 , wherein the quantity of E-PDCCH candidates is identified based on the identified DCI format and a quantity of resource elements (REs) in a physical resource block (PRB) pair for the E-PDCCH.
24. The base station of claim 22 ,
wherein the controller is further configured to identify whether the DCI format is included in a first group of DCI format or a second group of DCI format, and
wherein a number of bits of control information associated with the first group of DCI format is more than a number of bits of control information associated with the second group of DCI format.
25. The base station of claim 22 , wherein a number of bits of control information associated with each of DCI formats is different from each other.
26. The base station of claim 23 , wherein the quantity of REs in the PRB pair is calculated based on a quantity of REs for a common reference signal (CRS) and a channel state information reference signal (CSI-RS) in the PRB pair configured for the E-PDCCH.
27. The base station of claim 22 , wherein the controller is further configured to transmit information indicating whether the terminal monitors the E-PDCCH via a higher layer signaling.
28. The base station of claim 23 , wherein the quantity of E-PDCCH candidates is identified based on a downlink subframe type, the quantity of REs, and the DCI format.