Method of transmitting/receiving downlink control information and user equipment therefor in wireless access system
A method of receiving downlink control information and a corresponding apparatus in a wireless access system supporting an enhanced physical downlink control channel. The method includes receiving, from an eNB, DCI transmission channel information that indicates which one of a physical downlink control channel (PDCCH) and the e-PDCCH is used to transmit the DCI, checking the starting symbol of the e-PDCCH when the DCI transmission channel information indicates that the e-PDCCH is used to transmit the DCI, and receiving the DCI by performing blind decoding on the e-PDCCH from the starting symbol of the e-PDCCH.
1. A method of receiving downlink control information (DCI) by a user equipment (UE) via an enhanced physical downlink control channel (EPDCCH) multiplexed with a physical downlink shared channel (PDSCH) in a wireless access system supporting the EPDCCH , the method comprising:
receiving, from an eNB, an EPDCCH configuration indicating whether the EPDCCH for the UE is configured;
if the EPDCCH configuration contains an information indicating an EPDCCH starting symbol, receiving the EPDCCH from a starting OFDM (Orthogonal Frequency Division Multiplexing) symbol for the EPDCCH according to the information indicating EPDCCH starting symbol; and
if the EPDCCH configuration does not contain the information indicating the EPDCCH starting symbol, receiving the EPDCCH from a starting OFDM symbol for the EPDCCH which is determined by using a control format indicator (CFI) value based on a downlink bandwidth configuration.
2. The method according to claim 1 , wherein an index of the starting OFDM symbol for the EPDCCH is set as a value corresponding to the CFI value when the downlink bandwidth configuration is greater than 10 resource blocks.
3. The method according to claim 1 , wherein the EPDCCH configuration is transmitted from the eNB to the UE by using higher layer signaling.
4. The method according to claim 1 , the EPDCCH configuration further indicates a plurality of subframes for the EPDCCH by using a bitmap.
5. The method according to claim 1 , wherein the CFI value is received from the eNB via a PCFICH (Physical Control Format Indicator CHannel).
6. The method according to claim 1 , wherein the index of the starting OFDM symbol for the EPDCCH is the same as an index of a starting OFDM symbol for the PDSCH.
7. A user equipment (UE) for receiving DCI via an enhanced physical downlink control channel (EPDCCH) multiplexed with a physical downlink shared channel (PDSCH) in a wireless access system supporting the EPDCCH, the UE comprising:
a radio frequency (RF) unit configured to transmit/receive RF signals; and
a processor operatively connected to the RF unit,
wherein the processor is configured to
receive, from an eNB, an EPDCCH configuration indicating whether the EPDCCH for the UE is configured,
receive the EPDCCH from a starting OFDM (Orthogonal Frequency Division Multiplexing) symbol for the EPDCCH according to information indicating EPDCCH starting symbol, if the EPDCCH configuration contains the information indicating an EPDCCH starting symbol, and
receive the EPDCCH from a starting OFDM symbol for the EPDCCH which is determined by using a control format indicator (CFI) value based on a downlink bandwidth configuration, if the EPDCCH configuration does not contain the information indicating the EPDCCH starting symbol.
8. The UE according to claim 7 , wherein an index of the starting OFDM symbol for the EPDCCH is set as a value corresponding to the CFI value when the downlink bandwidth configuration is greater than 10 resource blocks.
9. The UE according to claim 7 , wherein the EPDCCH configuration is transmitted by using higher layer signaling.
10. The UE according to claim 7 , wherein the EPDCCH configuration further indicates a plurality of subframes for the EPDCCH by using a bitmap.
11. The UE according to claim 7 , wherein the CFI value is received from the eNB via a PCFICH (Physical Physical Control Format Indicator CHannel).
12. The UE according to claim 7 , wherein the index of the starting OFDM symbol for the EPDCCH is the same as an index of a starting OFDM symbol for the PDSCH.