A wireless communication system comprises a base station (4) and terminals (1)-(3). The base station (4) and the terminals (1)-(3) perform a space division multiplex wireless transmission. Each of the base station (4) and the terminals (1)-(3) comprises a multi-beam antenna for a space division multiplex. A beam pattern formed by the multi-beam antenna of the base station (4) is orthogonalized based on transfer function values of a radio-wave-propagation characteristic formed between antenna elements of the multi-beam antenna of the base station (4) and antenna elements of multi-beam antenna of the terminals (1)-(3).