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, channel state information reference signal (CSI-RS) configuration information; and
based on the CSI-RS configuration information, receiving, by the user equipment, CSI-RSs in at least one of plural subframes configured for the CSI-RSs, including a subframe where a physical broadcast channel (PBCH) 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 PBCH.
2. 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.
3. The method of claim 2 , 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 the subframe offset, and T CSI-RS is the periodicity.
4. 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 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 a physical broadcast channel (PBCH) 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 PBCH.
5. The user equipment of claim 4 , 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.
6. 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 the subframe offset, and T CSI-RS is the periodicity.
7. A method for transmitting, by a base station, downlink signals in a wireless communication system, the method comprising:
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 a physical broadcast channel (PBCH) 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 PBCH.
8. The method of claim 7 , 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.
9. The method of claim 8 , 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 the subframe offset, and T CSI-RS is the periodicity.
10. 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 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 a physical broadcast channel (PBCH) 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 PBCH.
11. The base station of claim 10 , 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 base station of claim 11 , 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 the subframe offset, and T CSI-RS is the periodicity.