Radio communication system, base station apparatus, mobile station apparatus and radio communication method

Abstract

A reference signal for channel estimation is transmitted a predetermined number of times with one signaling. In a radio communication system including a base station apparatus and a mobile station apparatus, the base station apparatus transmits a radio resource control signal including information indicating a number of times of transmission of the reference signal for channel estimation to the mobile station apparatus, and transmits a physical downlink control channel including information indicating transmission of the reference signal to the mobile station apparatus. The mobile station apparatus transmits the reference signal to the base station apparatus until the number of transmissions of the reference signal reaches the number of times of transmission, according to information, which is included in the radio resource control signal, when the information indicating transmission of the reference signal is included in the physical downlink control channel.

1 . A radio communication system comprising a base station apparatus and a mobile station apparatus, wherein
 the base station apparatus   transmits, to the mobile station apparatus, a radio resource control signal including information indicating a number of times of transmission of a reference signal for channel estimation, and transmits, to the mobile station apparatus, a physical downlink control channel including information indicating transmission of the reference signal, and   the mobile station apparatus   transmits the reference signal to the base station apparatus until a number of times of transmission reaches the number of times of transmission, according to the information indicating the number of times of transmission, which is included in the radio resource control signal when the information indicating transmission of the reference signal is included in the physical downlink control channel.   
     
     
         2 . The radio communication system according to  claim 1 , wherein
 the base station apparatus transmits, to the mobile station apparatus, a radio resource control signal including information indicating whether or not to perform frequency hopping of the reference signal, and   the mobile station apparatus transmits the reference signal to the base station apparatus while performing frequency hopping until a number of times of transmission reaches the number of times of transmission, according to the information indicating frequency hopping of the reference signal, which is included in the radio resource control signal.   
     
     
         3 . The radio communication system according to  claim 1 , wherein
 the base station apparatus transmits, to the mobile station apparatus, a radio resource control signal including information indicating whether or not the mobile station apparatus performs antenna selection, and   the mobile station apparatus transmits the reference signal to the base station apparatus while performing antenna selection until a number of times of transmission reaches the number of times of transmission, according to the information indicating antenna selection of the mobile station apparatus, which is included in the radio resource control signal.   
     
     
         4 . The radio communication system according to  claim 1 , wherein in the mobile station apparatus, a subframe transmitting the reference signal is set for each cell. 
     
     
         5 . The radio communication system according to  claim 1 , wherein in the mobile station apparatus, a subframe transmitting the reference signal is set for each the mobile station apparatus. 
     
     
         6 . The radio communication system according to  claim 1 , wherein in the mobile station apparatus, a subframe transmitting the reference signal, which is set for each the mobile station apparatus, includes a subframe capable of transmitting the reference signal, which is set for each the cell. 
     
     
         7 . A base station apparatus that communicates with a mobile station apparatus, the base station apparatus comprising:
 a transmitter for transmitting, to the mobile station apparatus, a radio resource control signal including information indicating a number of times of transmission of a reference signal for channel estimation; and   a transmitter for transmitting, to the mobile station apparatus, a physical downlink control channel including information indicating transmission of the reference signal.   
     
     
         8 . The base station apparatus according to  claim 7 , further comprising a transmitter for transmitting, to the mobile station apparatus, a radio resource control signal including information indicating whether or not to perform frequency hopping of the reference signal. 
     
     
         9 . The base station apparatus according to  claim 7 , further comprising a transmitter for transmitting, to the mobile station apparatus, a radio resource control signal including information indicating whether or not the mobile station apparatus performs antenna selection. 
     
     
         10 . A mobile station apparatus that communicates with a base station apparatus, the mobile station apparatus comprising
 a transmitter for transmitting, to the base station apparatus, the reference signal until a number of times of transmission reaches the number of times of transmission, according to the information indicating the number of times of transmission, which is included in the radio resource control signal, when the information indicating transmission of the reference signal is included in the physical downlink control channel.   
     
     
         11 . The mobile station apparatus according to  claim 10 , further comprising
 a transmitter for transmitting, to the base station apparatus, the reference signal while performing frequency hopping until a number of times of transmission reaches the number of times of transmission, according to the information indicating frequency hopping, which is included in the radio resource control signal.   
     
     
         12 . The mobile station apparatus according to  claim 10 , further comprising a transmitter for transmitting, to the base station apparatus, the reference signal while performing antenna selection until a number of times of transmission reaches the number of times of transmission, according to the information indicating antenna selection, which is included in the radio resource control signal. 
     
     
         13 . A radio communication method of a radio communication system including a base station apparatus and a mobile station apparatus, comprising at least the steps of:
 in the base station apparatus,   transmitting, to the mobile station apparatus, a radio resource control signal including information indicating a number of times of transmission of a reference signal for channel estimation, and   transmitting, to the mobile station apparatus, a physical downlink control channel including information indicating transmission of the reference signal, and   in the mobile station apparatus,   transmitting, to the base station apparatus, the reference signal until a number of times of transmission reaches the number of times of transmission, according to the information indicating the number of times of transmission, which is included in the radio resource control signal, when the information indicating transmission of the reference signal is included in the physical downlink control channel.   
     
     
         14 . The radio communication method according to  claim 13 , further comprising at least the steps of:
 in the base station apparatus, transmitting, to the mobile station apparatus, a radio resource control signal including information indicating whether or not to perform frequency hopping of the reference signal, and   in the mobile station apparatus, transmitting, to the base station apparatus, the reference signal while performing frequency hopping until a number of times of transmission reaches the number of times of transmission, according to the information indicating frequency hopping, which is included in the radio resource control signal.   
     
     
         15 . The radio communication method according to  claim 13 , further comprising at least the steps of:
 in the base station apparatus, transmitting, to the mobile station apparatus, a radio resource control signal including information indicating whether or not the mobile station apparatus performs antenna selection, and   in the mobile station apparatus, transmitting, to the base station apparatus, the reference signal while performing antenna selection until a number of times of transmission reaches the number of times of transmission, according to the information indicating antenna selection, which is included in the radio resource control signal.