A lower radio base station comprising: an acquisition unit, comprised in a radio baseband unit, configured to acquire channel state information indicating a channel state between the lower radio base station and a plurality of mobile terminals by estimation from uplink signals transmitted from the plurality of mobile terminals; a scheduler unit configured to convert the channel state information into a converted value of the channel state information representing a state of the channel between the lower radio base station and the mobile terminal in real scalar quantity notation, transmit the converted value of the channel state information to a higher radio base station, and determine the number of signal streams and a modulation and coding scheme for a destination terminal that is a first mobile terminal selected from among the plurality of mobile terminals, based on the destination terminal and a data transmission rate for the destination terminal sent for notification by the higher radio base station; and a signal processing unit comprised in the radio baseband unit, configured to generate Multi User-Multiple Input Multiple Output downlink baseband signals to a plurality of destination terminals selected by the higher radio base station including the first mobile terminal, wherein the converted value of the channel state information is calculated based on a transmission power of the mobile terminal, the number of antennas of the mobile terminal, a thermal noise power at the mobile terminal, and a channel matrix representing a state of the channel between the lower radio base station and the mobile terminal, wherein the converted value of the channel state information C m,j (f) is calculated from the following equation, using a channel matrix H m,j (f) at a radio frequency f between a lower base station 20-m and a mobile terminal 90-m-j, a transmission power P m (f) of the mobile terminal 90-m-j, a precoding matrix B m (f), a covariance matrix Ω j (f) determined from channel information on a component with interference of the mobile terminal 90-m-j, a thermal noise power σ 2 j of the mobile terminal 90-m-j, an identity matrix I with the number of receiving antenna ports of the mobile terminal 90-m-j being set as the order of the matrix, and weighting values α m and β π wherein 0≤α m ≤1 and 0≤β m ≤1 are fixed coefficients determined by requirements of the lower radio base station equation c m, j f = α m log 2 det I + P m f H m, j f B m, j f B m, j H f H m, j H f β m Ω j f + σ j 2 I an acquisition unit, comprised in a radio baseband unit, configured to acquire channel state information indicating a channel state between the lower radio base station and a plurality of mobile terminals by estimation from uplink signals transmitted from the plurality of mobile terminals; a scheduler unit configured to convert the channel state information into a converted value of the channel state information representing a state of the channel between the lower radio base station and the mobile terminal in real scalar quantity notation, transmit the converted value of the channel state information to a higher radio base station, and determine the number of signal streams and a modulation and coding scheme for a destination terminal that is a first mobile terminal selected from among the plurality of mobile terminals, based on the destination terminal and a data transmission rate for the destination terminal sent for notification by the higher radio base station; and a signal processing unit comprised in the radio baseband unit, configured to generate Multi User-Multiple Input Multiple Output downlink baseband signals to a plurality of destination terminals selected by the higher radio base station including the first mobile terminal, wherein the converted value of the channel state information is calculated based on a transmission power of the mobile terminal, the number of antennas of the mobile terminal, a thermal noise power at the mobile terminal, and a channel matrix representing a state of the channel between the lower radio base station and the mobile terminal, wherein the converted value of the channel state information C m,j (f) is calculated from the following equation, using a channel matrix H m,j (f) at a radio frequency f between a lower base station 20-m and a mobile terminal 90-m-j, a transmission power P m (f) of the mobile terminal 90-m-j, a precoding matrix B m (f), a covariance matrix Ω j (f) determined from channel information on a component with interference of the mobile terminal 90-m-j, a thermal noise power σ 2 j of the mobile terminal 90-m-j, an identity matrix I with the number of receiving antenna ports of the mobile terminal 90-m-j being set as the order of the matrix, and weighting values α m and β π wherein 0≤α m ≤1 and 0≤β m ≤1 are fixed coefficients determined by requirements of the lower radio base station equation c m, j f = α m log 2 det I + P m f H m, j f B m, j f B m, j H f H m, j H f β m Ω j f + σ j 2 I