Method, device, and system for signal transmission in unlicensed band
Disclosed relates to a method, device, and system for performing downlink transmission. Specifically, the disclosed relates to a method including when the downlink signal includes a physical downlink shared channel (PDSCH) and a channel in the specific cell is sensed to be idle for a first predefined interval, wherein the processor performs backoff after the second predefined time in order to perform the downlink transmission, and when the downlink transmission includes a Discovery Reference Signal (DRS) and the channel in the specific cell is sensed to be idle for a second predefined interval, performing the downlink transmission immediately after the second predefined interval, and a device and system therefor.
1. A base station transmitting a downlink transmission in a specific cell in a cellular wireless communication system, the base station comprising:
a wireless communication module; and
a processor,
wherein when the downlink transmission including a Discovery Reference Signal (DRS) is transmitted in an unlicensed cell, the processor is configured to transmit the DRS in any subframe within a periodically-configured Discovery Measurement Timing Configuration (DMTC) and a last OFDM symbol of a subframe including the DRS to be empty.
2. The base station of claim 1 , wherein the DRS includes at least one of Cell-specific Reference Signal (CRS), Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), and Channel State Information (CSI)-RS.
3. The base station of claim 1 , wherein when the downlink transmission including the DRS is transmitted in a licensed cell, the processor is configured to transmit one to five consecutive subframes including the DRS in the licensed cell.
4. The base station of claim 1 , wherein when the downlink transmission including the DRS is transmitted in a licensed cell, the processor is configured to transmit two to five consecutive subframes including the DRS in the licensed cell.
5. A user equipment receiving a downlink transmission in a specific cell in a cellular wireless communication system, the user equipment comprising:
a wireless communication module; and
a processor,
wherein the processor is configured to receive a subframe including a Discovery Reference Signal (DRS), and perform a Radio Resource Management (RRM) measurement based on the DRS,
wherein when the downlink transmission including the DRS is received in an unlicensed cell, a last OFDM symbol of the subframe is empty and the DRS is transmitted in any subframe within a periodically-configured Discovery Measurement Timing Configuration (DMTC) by a base station.
6. The user equipment of claim 5 , wherein the DRS includes at least one of Cell-specific Reference Signal (CRS), Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), and Channel State Information (CSI)-RS.
7. The user equipment of claim 5 , wherein when the downlink transmission including the DRS is received in a licensed cell, the processor is configured to receive one to five consecutive subframes including the DRS in the licensed cell.
8. The user equipment of claim 5 , wherein when the downlink transmission including the DRS is received in a licensed cell, the processor is configured to receive two to five consecutive subframes including the DRS in the licensed cell.
9. A method of operation of a user equipment receiving a downlink transmission in a specific cell in a cellular wireless communication system, the method comprising:
receiving a subframe including a Discovery Reference Signal (DRS), and
performing a Radio Resource Management (RRM) measurement based on the DRS,
wherein when the downlink transmission including the DRS is received in an unlicensed cell, a last OFDM symbol of the subframe is empty and the DRS is transmitted in any subframe within a periodically-configured Discovery Measurement Timing Configuration (DMTC) by a base station.
10. The method of claim 9 , wherein the DRS includes at least one of Cell-specific Reference Signal (CRS), Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), and Channel State Information (CSI)-RS.
11. The method of claim 9 , further comprising when the downlink transmission including the DRS is received in a licensed cell, one to five consecutive subframes including the DRS are received in the licensed cell.
12. The method of claim 9 , further comprising when the downlink transmission including the DRS is received in a licensed cell, two to five consecutive subframes including the DRS are received in the licensed cell.