Method and apparatus for performing cell on/off operation in wireless communication system
A method and apparatus for transmitting a periodic reference signal in a wireless communication system is provided. An evolved NodeB (eNB) configures a periodic reference signal, and transmits the periodic reference signal in a specific duration. The periodic reference signal may be a discovery reference signal (DRS) or a channel state information reference signal (CSI RS). The periodic reference signal may be transmitted flexibly or transmitted by performing listen-before-talk (LBT) with reservation of transmission of the periodic reference signal.
1. A method for transmitting, by an evolved NodeB (eNB) which operates in LTE in an unlicensed (LTE-U) spectrum, a discovery reference signal (DRS) in a wireless communication system, the method comprising:
configuring, by the eNB, a periodic transmission of the DRS with DRS occasion;
starting, by the eNB, carrier sensing on a channel related to a wireless local area network (WLAN), before the DRS occasion by an amount of time equal to a maximum allowed channel occupancy time of the WLAN;
detecting, by the eNB, when the channel is idle;
occupying, by the eNB, the channel immediately after the channel becomes idle;
transmitting, by the eNB, a reservation signal until the DRS occasion; and
transmitting, by the eNB, the DRS in the DRS occasion,
wherein a periodicity of the DRS occasion is longer than the maximum allowed channel occupancy time.
2. The method of claim 1 , wherein the DRS occasion consists of 3 subframes every 40 ms.
3. The method of claim 1 , further comprising:
performing listen-before-talk (LBT) before transmitting the DRS.
4. The method of claim 3 , further comprising:
transmitting the reservation signal after performing the LBT and the channel becomes idle.
5. An evolved NodeB (eNB) which operates in LTE in an unlicensed (LTE-U) spectrum, the eNB comprising:
a memory;
a transceiver; and
a processor, operatively coupled to the memory and the transceiver, wherein the processor is configured to:
configure a periodic transmission of a discovery reference signal (DRS) with DRS occasion:
start carrier sensing on a channel related to a wireless local area network (WLAN), before the DRS occasion by an amount of time equal to a maximum allowed channel occupancy time of the WLAN;
detect when the channel is idle;
occupy the channel immediately after the channel becomes idle;
control the transceiver to transmit a reservation signal until the DRS occasion; and
control the transceiver to transmit DRS in the DRS occasion,
wherein a periodicity of the DRS occasion is longer than the maximum allowed channel occupancy time.