Method and apparatus for performing handover in c-ran system

Abstract

A method and apparatus for performing handover by a user equipment (UE) in a C-RAN system is disclosed. The method for performing handover by a user equipment (UE) in a Cloud Radio Access Network (C-RAN) includes: measuring at least one candidate remote radio head (RRH); transmitting feedback information caused by the measurement to a primary RRH; and receiving information regarding a changed primary RRH according to the measurement result received from the primary RRH, wherein the measurement is performed to discriminate each RRH on the basis of a channel state information-reference signal (CSI-RS) antenna port discriminated per the at least one candidate RRH.

1 . A method for performing handover by a user equipment (UE) in a Cloud Radio Access Network (C-RAN), the method comprising:
 measuring at least one candidate remote radio head (RRH);   transmitting feedback information caused by the measurement to a primary RRH; and   receiving information regarding a changed primary RRH from the primary RRH according to a result of the measurement,   wherein the measurement is performed to discriminate each RRH on the basis of a channel state information-reference signal (CSI-RS) antenna port discriminated per the at least one candidate RRH.   
     
     
         2 . The method according to  claim 1 , further comprising:
 receiving list information of the at least one candidate RRH from a base station (BS) or the primary RRH.   
     
     
         3 . The method according to  claim 1 , wherein the at least one candidate RRH includes the primary RRH and an RRH communicating with the UE. 
     
     
         4 . The method according to  claim 1 , wherein the changed primary RRH corresponds to an RRH having a highest signal intensity from among the measurement result. 
     
     
         5 . The method according to  claim 1 , further comprising:
 transmitting a RACH to the changed primary RRH through RRH dedicated RACH resources.   
     
     
         6 . The method according to  claim 1 , further comprising:
 receiving information regarding a CSI-RS antenna port discriminated per RRH from a base station (BS).   
     
     
         7 . A user equipment (UE) for performing handover in a Cloud Radio Access Network (C-RAN) comprising:
 a receiver;   a transmitter; and   a processor,   wherein the processor measures at least one candidate remote radio head (RRH), controls the transmitter to transmit feedback information caused by the measurement to a primary RRH, and controls the receiver to receive information regarding a changed primary RRH from the primary RRH according to a result of the measurement, and the processor performs the measurement to discriminate each RRH on the basis of a channel state information-reference signal (CSI-RS) antenna port discriminated per the at least one candidate RRH.   
     
     
         8 . The user equipment (UE) according to  claim 7 , wherein the processor receives list information of the at least one candidate RRH from a base station (BS) or the primary RRH. 
     
     
         9 . The user equipment (UE) according to  claim 7 , wherein the at least one candidate RRH includes the primary RRH and an RRH communicating with the UE. 
     
     
         10 . The user equipment (UE) according to  claim 7 , wherein the processor controls the transmitter to transmit a RACH to the changed primary RRH through RRH dedicated RACH resources. 
     
     
         11 . The user equipment (UE) according to  claim 7 , wherein the processor controls the receiver to receive information regarding a CSI-RS antenna port discriminated per RRH from a base station (BS). 
     
     
         12 . The user equipment (UE) according to  claim 7 , wherein the changed primary RRH corresponds to an RRH having the highest signal intensity from among the measurement result.