A radio communication system comprising a user terminal and a radio base station apparatus to which the user terminal is connected, wherein: the radio base station apparatus comprises: an acquisition section configured to acquire, from a plurality of transmission points, radio resource allocation information to represent a signal transmission state at each transmission point, over an entire system band; a determining section configured to determine a subband pattern to indicate subbands where the signal transmission state is the same between the plurality of transmission points, based on the acquired radio resource allocation information; and a transmission section configured to transmit a reporting signal to indicate the determined subband pattern to the user terminal; and the user terminal comprises: a receiving section configured to receive the reporting signal and to acquire the subband pattern; and an interference measurement section configured to perform interference measurement over the entire system band, and, to average the interference measurement results in the indicated subbands, based on the acquired subband pattern, wherein the determining section is configured to determine the subband pattern which includes one subband or a plurality of subbands of a fixed bandwidth depending on the bandwidth in which the signal transmission state is the same between the plurality of transmission points. the radio base station apparatus comprises: an acquisition section configured to acquire, from a plurality of transmission points, radio resource allocation information to represent a signal transmission state at each transmission point, over an entire system band; a determining section configured to determine a subband pattern to indicate subbands where the signal transmission state is the same between the plurality of transmission points, based on the acquired radio resource allocation information; and a transmission section configured to transmit a reporting signal to indicate the determined subband pattern to the user terminal; and the user terminal comprises: a receiving section configured to receive the reporting signal and to acquire the subband pattern; and an interference measurement section configured to perform interference measurement over the entire system band, and, to average the interference measurement results in the indicated subbands, based on the acquired subband pattern, wherein the determining section is configured to determine the subband pattern which includes one subband or a plurality of subbands of a fixed bandwidth depending on the bandwidth in which the signal transmission state is the same between the plurality of transmission points. an acquisition section configured to acquire, from a plurality of transmission points, radio resource allocation information to represent a signal transmission state at each transmission point, over an entire system band; a determining section configured to determine a subband pattern to indicate subbands where the signal transmission state is the same between the plurality of transmission points, based on the acquired radio resource allocation information; and a transmission section configured to transmit a reporting signal to indicate the determined subband pattern to the user terminal; and the user terminal comprises: a receiving section configured to receive the reporting signal and to acquire the subband pattern; and an interference measurement section configured to perform interference measurement over the entire system band, and, to average the interference measurement results in the indicated subbands, based on the acquired subband pattern, wherein the determining section is configured to determine the subband pattern which includes one subband or a plurality of subbands of a fixed bandwidth depending on the bandwidth in which the signal transmission state is the same between the plurality of transmission points. a receiving section configured to receive the reporting signal and to acquire the subband pattern; and an interference measurement section configured to perform interference measurement over the entire system band, and, to average the interference measurement results in the indicated subbands, based on the acquired subband pattern, wherein the determining section is configured to determine the subband pattern which includes one subband or a plurality of subbands of a fixed bandwidth depending on the bandwidth in which the signal transmission state is the same between the plurality of transmission points.