Method and apparatus for reporting a measurement in a wireless communication system
The present invention relates to a method for reporting a measurement by a terminal, comprising the steps of: measuring the magnitude of a signal from a first transmission point; and measuring the magnitude of a signal from a second transmission point. The measurements of the magnitudes of the signals from each transmission point are performed using a channel state information reference signal.
1. A method for performing measurement reporting at a User Equipment (UE) in a wireless communication system, the method comprising:
receiving, from a serving cell, a neighboring cell list;
measuring channel state information (CSI) using a first CSI-reference signal (CSI-RS) from the serving cell;
reporting a result of the CSI measurement to the serving cell;
measuring radio resource management (RRM) using a second CSI-RS from a neighboring cell;
reporting a result of the RRM measurement to the serving cell; and
transmitting a random access preamble to a neighboring cell based on an equation min{Pcmax, PRTP+PLc}, where Pcmax is maximum transmission power allowed to the UE, PRTP is preamble received target power, and PLc is pathloss determined based on a result of the RRM measurement of the second CSI-RS,
wherein the first CSI-RS and the second CSI-RS belong to a specific CSI-RS configuration and are transmitted with different CSI-RS antenna port numbers of the specific CSI-RS configuration by the serving cell and the neighboring cell respectively, and
wherein the serving cell and the neighboring cell are distinguished from each other by the different CSI-RS antenna port numbers, the different CSI-RS antenna port numbers being signaled by the neighbor cell list.
2. The method according to claim 1 , wherein the serving cell and the neighboring cell perform cooperative transmission for the UE.
3. The method according to claim 1 , wherein the second CSI-RS signal is transmitted from a first transmission point of the neighboring cell.
4. The method according to claim 3 , further comprising:
receiving a third CSI-RS signal from a second transmission point of the neighboring cell,
wherein the UE recognizes each of the transmission points that transmit the second CSI-RS and the third CSI-RS respectively using at least one of CSI-RS subframe configurations, CSI-RS configurations, and CSI-RS antenna ports.
5. The method according to claim 1 , further comprising:
receiving information about an antenna port used for transmitting for the first CSI-RS from the serving cell.
6. The method according to claim 1 , further comprising:
receiving a CSI-RS subframe configuration used for transmitting the first CSI-RS from the serving cell.
7. The method according to claim 1 , wherein the RRM measurement includes a reference signal received strength (RSRP) of the second CSI-RS.
8. The method according to claim 1 , wherein a magnitude of the second CSI-RS is measured by calculating a linear average of power of resource elements carrying the second CSI-RS, total reception power, and a number of resource blocks in a corresponding bandwidth, used for measuring the total reception power.
9. A User Equipment (UE) for performing measurement reporting in a wireless communication system, the UE comprising:
a transmitter; and
a processor operatively connected to the transmitter and configured to:
receive, from a serving cell, a neighboring cell list,
measure channel state information (CSI) using a first CSI-reference signal (CSI-RS) from the serving cell,
report a result of the CSI measurement to the serving cell,
measure radio resource management (RRM) using a second CSI-RS from a neighboring cell,
report a result of the RRM measurement to the serving cell, and
transmit a random access preamble to a neighboring cell based on an equation min{Pcmax, PRTP+PLc}, where Pcmax is maximum transmission power allowed to the UE, PRTP is preamble received target power, and PLc is pathloss determined based on a result of the RRM measurement of the second CSI-RS,
wherein the first CSI-RS and the second CSI-RS belong to a specific CSI-RS configuration and are transmitted with different CSI-RS antenna port numbers of the specific CSI-RS configuration by the serving cell and the neighboring cell respectively, and
wherein the serving cell and the neighboring cell are distinguished from each other by the different CSI-RS antenna port numbers, the different CSI-RS antenna port numbers being signaled by the neighbor cell list.