Method and base station for receiving reference signal, and method and user equipment for receiving reference signal
A base station does not transmit any reference signal (RS) for channel measurement in a subframe in which transmission of an RS collides with transmission of a synchronization signal or a broadcast signal or in a resource block including the synchronization signal or the broadcast signal in the subframe. A user equipment assumes that any RS for channel measurement is not transmitted in a subframe or in a resource block when transmission of an RS collides with transmission of a synchronization signal or a broadcast signal in the subframe or in the resource block.
1. A method for receiving, by a user equipment, downlink signals in a wireless communication system, the method comprising:
receiving, by the user equipment, a synchronization signal over a predetermined number of resource blocks among a plurality of resource blocks forming a downlink frequency bandwidth at every 5 subframes;
receiving, by the user equipment, channel state information reference signal (CSI-RS) configuration information; and
based on the CSI-RS configuration information, receiving, by the user equipment, CSI-RSs over the downlink frequency bandwidth in at least one of plural subframes configured for the CSI-RSs, including a subframe where the synchronization signal is present, while assuming none of the CSI-RSs corresponding to the CSI-RS configuration information are present in a subframe where a reception of any CSI-RS of the CSI-RSs collides with a reception of the synchronization signal.
2. The method of claim 1 , wherein the synchronization signal is received in 0 th and 5 th subframes in every radio frame, the radio frame including 0 th to 9 th subframes.
3. The method of claim 1 , wherein the CSI-RS configuration information includes at least one of information indicating a number of antenna ports used to transmit the CSI-RSs, information indicating positions of the CSI-RSs within a resource block, and information indicating a periodicity for the CSI-RSs and a subframe offset for the CSI-RSs.
4. The method of claim 1 , wherein the plural subframes configured for the CSI-RS satisfy:
(10× n f +└n s /2┘−Δ CSI-RS )mod T CSI-RS =0,
where n f is a system frame number, └n s /2┘ is a subframe number n s is a slot number within a radio frame, Δ CSI-RS is a CSI-RS subframe offset, and T CSI-RS is a CSI-RS periodicity.
5. A user equipment for receiving downlink signals in a wireless communication system, the user equipment comprising:
a receiver; and
a processor configured to control the receiver to
receive a synchronization signal over a predetermined number of resource blocks among a plurality of resource blocks forming a downlink frequency bandwidth at every 5 subframes;
receive channel state information reference signal (CSI-RS) configuration information; and
based on the CSI-RS configuration information, receive CSI-RSs over the downlink frequency bandwidth in at least one of plural subframes configured for the CSI-RSs, including a subframe where the synchronization signal is present, while assuming none of the CSI-RSs corresponding to the CSI-RS configuration information are present in a subframe where a reception of any CSI-RS of the CSI-RSs collides with a reception of the synchronization signal.
6. The user equipment of claim 5 , wherein the processor is configured to control the receiver to receive the synchronization signal in 0 th and 5 th subframes in every radio frame, the radio frame including 0 th to 9 th subframes.
7. The user equipment of claim 5 , wherein the CSI-RS configuration information includes at least one of information indicating a number of antenna ports used to transmit the CSI-RSs, information indicating positions of the CSI-RSs in a resource block, and information indicating a periodicity for the CSI-RSs and a subframe offset for the CSI-RSs.
8. The user equipment of claim 5 , wherein the plural subframes configured for the CSI-RS satisfy:
(10× n f +└n s /2┘−Δ CSI-RS )mod T CSI-RS =0,
where n f is a system frame number, └n s /2┘ is a subframe number, n s is a slot number within a radio frame, Δ CSI-RS is a CSI-RS subframe offset, and T CSI-RS is a CSI-RS periodicity.
9. A method for transmitting, by a base station, downlink signals in a wireless communication system, the method comprising:
transmitting, by the base station, a synchronization signal over a predetermined number of resource blocks among a plurality of resource blocks forming a downlink frequency bandwidth at every 5 subframes; and
transmitting, by the base station, channel state information reference signal (CSI-RS) configuration information; and
based on the CSI-RS configuration information, transmitting, by the base station, CSI-RSs over the downlink frequency bandwidth in at least one of plural subframes configured for the CSI-RSs, including a subframe where the synchronization signal is present, while transmitting none of the CSI-RSs corresponding to the CSI-RS configuration information in a subframe where a transmission of any CSI-RS of the CSI-RSs collides with a transmission of the synchronization signal.
10. The method of claim 9 , wherein the synchronization signal is transmitted in 0 th and 5 th subframes in every radio frame, the radio frame including 0 th to 9 th subframes.
11. The method of claim 9 , wherein the CSI-RS configuration information includes at least one of information indicating a number of antenna ports used to transmit the CSI-RSs, information indicating positions of the CSI-RSs in a resource block, and information indicating a periodicity for the CSI-RSs and a subframe offset for the CSI-RSs.
12. The method of claim 9 , wherein the plural subframes configured for the CSI-RS satisfy:
(10× n f +└n s /2┘−Δ CSI-RS )mod T CSI-RS =0,
where n f is a system frame number, └n s /2┘ is a subframe number, n s is a slot number within a radio frame, Δ CSI-RS is a CSI-RS subframe offset, and T CSI-RS is a CSI-RS periodicity.
13. A base station for transmitting downlink signals in a wireless communication system, the base station comprising:
a transmitter; and
a processor configured to control the transmitter to:
transmit a synchronization signal over a predetermined number of resource blocks among a plurality of resource blocks forming a downlink frequency bandwidth at every 5 subframes;
transmit channel state information reference signal (CSI-RS) configuration; and
based on the CSI-RS configuration information, transmit CSI-RSs over the downlink frequency bandwidth in at least one of plural subframes configured for the CSI-RSs, including a subframe where the synchronization signal is present, while transmitting none of the CSI-RSs corresponding to the CSI-RS configuration information in a subframe where a transmission of any CSI-RS of the CSI-RSs collides with a transmission of the synchronization signal.
14. The base station of claim 13 , wherein the processor is configured to control the transmitter to transmit the synchronization signal in 0 th and 5 th subframes in every radio frame, the radio frame including 0 th to 9 th subframes.
15. The base station of claim 13 , wherein the CSI-RS configuration information includes at least one of information indicating a number of antenna ports used to transmit the CSI-RSs, information indicating positions of the CSI-RSs in a resource block, and information indicating a periodicity for the CSI-RSs and a subframe offset for the CSI-RSs.
16. The base station of claim 13 , wherein the plural subframes configured for the CSI-RS satisfy:
(10× n f +└n s /2┘−Δ CSI-RS )mod T CSI-RS =0,
where n f is a system frame number, └n s /2┘ is a subframe number, n s is a slot number within a radio frame, Δ CSI-RS is a CSI-RS subframe offset, and T CSI-RS is a CSI-RS periodicity.