Method for receiving downlink control information in wireless communication system and device therefor
The present invention relates to a method by which a terminal receives downlink control information in a wireless communication system and, more specifically, the method comprises the step of receiving a specific reference signal (RS) in a common search space (CSS) of an enhanced physical downlink control channel (EPDCCH), wherein the specific reference signal is punctured and transmitted when a position allocated to a first terminal in an initial access procedure cannot be commonly applied to a second terminal.
1. A method for receiving downlink control information by a first user equipment (UE) in a wireless communication system, the method comprising:
configuring a start OFDM (Orthogonal Frequency Division Multiplexing) symbol location of a common search space (CSS) in an initial access procedure; and
monitoring an enhanced physical downlink control channel (EPDCCH) on the CSS,
wherein the CSS includes a specific reference signal and downlink control information of the EPDCCH,
wherein, if a specific location allocated to the first UE in the initial access procedure is not commonly applicable to a second UE, the specific reference signal is mapped on resource elements excluding the specific location through a puncturing,
wherein the downlink control information of the EPDCCH is allocated through a rate matching to a subframe excluding the resource elements to which the specific reference signal is mapped, and
wherein the downlink control information is first allocated from the start OFDM symbol location toward a last OFDM symbol of the subframe and then allocated from the start OFDM symbol location toward an initial OFDM symbol of the subframe.
2. The method according to claim 1 , wherein the specific reference signal is a channel state information reference signal (CSI-RS).
3. The method according to claim 2 , further comprising performing channel measurement based on the CSI-RS and transmitting a resultant value of the channel measurement.
4. The method according to claim 1 , wherein the specific reference signal is a CSI-RS pre-configured for channel estimation or radio resource management (RRM).
5. The method according to claim 1 , further comprising:
receiving configuration information of the specific reference signal.
6. The method according to claim 1 , wherein the specific reference signal is transmitted using a rate matching (RM) scheme if the specific location allocated to the first UE in the initial access procedure is commonly applicable to the second UE.
7. A user equipment (UE) for receiving downlink information in a wireless communication system, the UE comprising:
a radio frequency (RF) unit; and
a processor,
wherein the processor is configured to:
configure a start OFDM (Orthogonal Frequency Division Multiplexing) symbol location of a common search space (CSS) in an initial access procedure, and
monitor an enhanced physical downlink control channel (EPDCCH),
wherein the CSS includes a specific reference signal and downlink control information of the EPDCCH,
wherein, if a specific location assigned to the UE in the initial access procedure is not commonly applicable to another UE, the specific reference signal is mapped on resource elements excluding the specific location through a puncturing,
wherein the downlink control information of the EPDCCH is allocated through a rate matching to a subframe excluding the resource elements to which the specific reference signal is mapped, and
wherein the downlink control information is first allocated from the start OFDM symbol location toward a last OFDM symbol of the subframe and then allocated from the start OFDM symbol location toward an initial OFDM symbol of the subframe.