Patent ID: 7319683

Claim:
A radio base station that performs radio communication with a plurality of mobile stations according to spatial multiplexing, comprising: a detection means for detecting the reception timing difference between a signal received from a mobile station already communicating with the radio base station and a signal received from a mobile station that is newly initiating communication with the radio base station; and a multiplex judgment means for judging, by comparing the detected reception timing difference with a threshold value, whether the mobile station that is newly initiating communication with the radio base station can be included as a member for the spatial multiplexing, wherein judging whether the spatial multiplexing is applicable based on a reception timing difference between the signal received from the mobile station already communicating with the radio base station and the signal received from the mobile station that is newly initiating communication with the radio base station; a calculation means for calculating (a) a correlation value between a response vector of the mobile station already communicating with the radio base station and a response vector of the mobile station that is newly initiating communication with the radio base station, and (b) a ration of a field intensity of the signal received from the mobile station already communicating with the radio base station to a field intensity of the signal received from the mobile station that is newly initiating communication with the radio base station, wherein the multiplex judgment means judges whether the mobile station that is newly initiating communication with the radio base station can be included as a member for spatial multiplexing, by comparing the calculated correlation value between the response vectors, the calculated ratio of the field intensity, and the detected reception timing difference, with respective threshold values.