Downlink signal reception method and user equipment, and downlink signal transmission method and base station
A control channel (CCH) is transmitted/received within a search space which is a group of CCH candidates. The CCH is transmitted/received in one of the CCH candidates. The search space spans N (N is a positive integer) time symbols among the multiple time symbols, and is configured to include a greatest number of CCH candidates in the first time symbols among the N time symbols.
1. A method of receiving a downlink signal by a user equipment, the method comprising:
detecting a control channel (CCH) from one of CCH candidates by monitoring the CCH candidates in a search space which is a set of the CCH candidates of an aggregation level L (where L is a positive integer) within a time transmission interval (TTI); and
receiving downlink data based on downlink control information carried by the CCH,
wherein the TTI includes a plurality of time symbols in a time domain,
wherein the search space spans N time symbols (where N is a positive integer) among the plural time symbols,
wherein each of the CCH candidates consists of one of the N time symbols in the time domain and L control channel elements (CCEs) in a frequency domain, and
wherein the search space includes a greatest number of CCH candidates on a first time symbol of the N time symbols.
2. The method of claim 1 , wherein the search space includes a greater number of CCH candidates on a time symbol having a low time symbol index than on a time symbol having a high time symbol index among the N time symbols.
3. The method of claim 1 , further comprising:
receiving configuration information on the search space.
4. The method of claim 1 , wherein each of the CCH candidates in the search space consists of CCEs located in the same time symbol.
5. A user equipment for receiving a downlink signal, the user equipment comprising,
a radio frequency (RF) module, and
a processor configured to control the RF module,
wherein the processor:
detects a control channel (CCH) from one of CCH candidates by monitoring the CCH candidates in a search space which is a set of the CCH candidates of an aggregation level L (where L is a positive integer) within a time transmission interval (TTI); and
controls the RF module to receive downlink data based on downlink control information carried by the CCH,
wherein the TTI includes a plurality of time symbols in a time domain,
wherein the search space spans N time symbols (where N is a positive integer) among the plural time symbols,
wherein each of the CCH candidates consists of one of the N time symbols in the time domain and L control channel elements (CCEs) in a frequency domain, and
wherein the search space includes a greatest number of CCH candidates on a first time symbol of the N time symbols.
6. The user equipment of claim 5 , wherein the search space includes a greater number of CCH candidates on a time symbol having a low time symbol index than on a time symbol having a high time symbol index among the N time symbols.
7. The user equipment of claim 5 , wherein the processor controls the RF module to receive configuration information on the search space.
8. The user equipment of claim 5 , wherein each of the CCH candidates in the search space consists of CCEs located in the same time symbol.
9. A base station for transmitting a downlink signal, the base station comprising:
a radio frequency (RF) module, and
a processor configured to control the RF module,
wherein the processor:
controls the RF module to transmit a control channel (CCH) using one of CCH candidates in a search space which is a set of the CCH candidates of an aggregation level L (where L is a positive integer) within a time transmission interval (TTI); and
controls the RF module to transmit downlink data based on downlink control information carried by the CCH,
wherein the TTI includes a plurality of time symbols in a time domain,
wherein the search space spans N time symbols (where N is a positive integer) among the plural time symbols,
wherein each of the CCH candidates consists of one of the N time symbols in the time domain and L control channel elements (CCEs) in a frequency domain, and
wherein the search space includes a greatest number of CCH candidates on a first time symbol of the N time symbols.
10. The base station of claim 9 , wherein the search space includes a greater number of CCH candidates on a time symbol having a low time symbol index than on a time symbol having a high time symbol index among the N time symbols.
11. The base station of claim 9 , wherein the processor controls the RF module to transmit configuration information on the search space.
12. The base station of claim 9 , wherein each of the CCH candidates in the search space consists of CCEs located in the same time symbol.