To provide a wireless base station that can avoid a disabled speech when there is possibility of a disabled speech because reception timings of symbol sequences subjected to spatial multiplex processing from mobile stations are close to each other.

A transmission timing adjustment section 53 calculates transmission timing of a symbol sequence to a mobile station so as to obtain a reception timing difference ΔtR having a prescribed value or over when the reception timing difference ΔtR of the symbol sequences from two mobile stations is less than the prescribed value and informs a clock generating section 52 about the transmission timing. Receiving a notice of new transmission timing, the clock generating section 52 generates clocks that are sequentially shifted by Δtc per transmission slot until the generating timing of the current clock reaches the informed transmission timing, and a signal adjustment section 51 transmits the symbol sequence to the mobile stations according to the clock generated by the clock generating section 52.