Method and apparatus for performing channel sensing in a wireless communication system
Provided is a method for performing channel sensing by a node. The node receives information about a known signal to be transmitted by at least one node of a node group that the node performing the channel sensing belongs to, detects the known signal using the information about the known signal, cancels reception power of the known signal from measured reception power, during a time period in which the known signal is detected, compares remaining reception power except for the reception power with a threshold, and determines whether a channel is occupied or unoccupied according to the comparison. The information about the known signal includes a sequence of the known signal, a power offset between a transmission signal and the known signal during a valid duration of the reception power of the known signal, or a cancellation ratio of reception power of the transmission signal during the valid duration.
1. A method for transmitting a signal in an unlicensed band by a first base station (BS), included in a predetermined BS group within a network of a single operator, in a wireless communication system, the method comprising:
transmitting, to a second BS, information on a range of a transmission power of the signal which the first BS intends to transmit;
receiving, from the second BS, a request to reduce the transmission power in response to the information on the range;
receiving, from the second BS, a first known signal, on a time duration, to which a first orthogonal cover code (OCC) is applied,
wherein the first known signal comprises a first sequence generated based on a first identifier (ID) on identifying whether the second BS is included in the predetermined BS group, and
wherein the predetermined BS group consists of a plurality of BSs configured to allow simultaneous transmission in the unlicensed band;
identifying, based on the first ID, whether the second BS included in the predetermined BS group; and
based on being identified that the second BS is included in the predetermined BS group:
performing a channel sensing based on applying a second OCC, orthogonal to the first OCC, to the time duration to cancel a reception power of the first known signal during the channel sensing; and
transmitting, based on the channel sensing, the signal with the transmission power in the unlicensed band,
wherein the transmission power is determined, based on the request, as a value, within the range, to enable simultaneous transmission in the unlicensed band between the first BS and the second BS.
2. The method of claim 1 , wherein identifying whether the second BS included in the predetermined BS group is performed in case of a second known signal received on the time duration, and
wherein the second known signal comprises a second sequence generated based on a second ID related to another operator which is different from the single operator.
3. A first base station (BS), included in a predetermined BS group within a network of a single operator, for transmitting a signal in an unlicensed band in a wireless communication system, the first BS comprising:
a memory; and
at least one processor coupled with the memory and configured to:
transmit, to a second BS, information on a range of a transmission power of the signal which the first BS intends to transmit;
receive, from the second BS, a request to reduce the transmission power in response to the information on the range;
receive, from the second BS, a first known signal, on a time duration, to which a first orthogonal cover code (OCC) is applied,
wherein the first known signal comprises a first sequence generated based on a first identifier (ID) on identifying whether the second BS is included in the predetermined BS group, and
wherein the predetermined BS group consists of a plurality of BSs configured to allow simultaneous transmission in the unlicensed band;
identify, based on the first ID, whether the second BS included in the predetermined BS group; and
based on being identified that the second BS is included in the predetermined BS group:
perform a channel sensing based on applying a second OCC, orthogonal to the first OCC, to the time duration to cancel a reception power of the first known signal during the channel sensing; and
transmit, based on the channel sensing, the signal with the transmission power in the unlicensed band,
wherein the transmission power is determined, based on the request, as a value, within the range, to enable simultaneous transmission in the unlicensed band between the first BS and the second BS.
4. The first BS of claim 3 , wherein the at least one processor is further configured to identify whether the second BS included in the predetermined BS group in case of a second known signal received on the time duration, and
wherein the second known signal comprises a second sequence generated based on a second ID related to another operator which is different from the single operator.