A controller for controlling transmission availability for a radio station in a radio communication system, comprising: an information acquisition unit configured to acquire radio communication state information on another radio station different from the radio station via a backbone network connected to the radio station and the other radio station, the radio communication state information including frequency information indicative of a frequency band used by the other radio station and waveform feature information indicative of a waveform feature of a radio signal transmitted from the other radio station, the waveform feature including cyclostationarity derived from second order periodic autocorrelations, variances of signal amplitudes or frequency correlations; a waveform information extraction unit configured to receive a radio signal and calculate a waveform feature based on the waveform feature information, the waveform feature indicating whether the received radio signal includes the radio signal transmitted from the other radio station; and a radio resource parameter determination unit configured to determine whether signal transmission from the radio station is available by comparing a waveform feature threshold with the waveform feature calculated by the waveform information extraction unit and to specify a radio resource to be used for the signal transmission based on the frequency information, the waveform feature information and/or the calculated waveform feature; wherein the radio resource parameter determination unit comprises a quality estimation table including correspondence between a peak amount of a waveform feature and signal quality of a channel between the radio station and the other radio station, and the radio resource parameter determination unit is configured to estimate the signal quality of the channel based on the calculated waveform feature indicative of the waveform feature of the radio signal transmitted from the other radio station with reference to the quality estimation table to determine whether signal transmission from the radio station is available by determining whether a desired communication quality is achievable under a transmit power constraint for limiting interference caused to the other radio station to be below a predefined level and specify a radio resource to be used for the signal transmission. an information acquisition unit configured to acquire radio communication state information on another radio station different from the radio station via a backbone network connected to the radio station and the other radio station, the radio communication state information including frequency information indicative of a frequency band used by the other radio station and waveform feature information indicative of a waveform feature of a radio signal transmitted from the other radio station, the waveform feature including cyclostationarity derived from second order periodic autocorrelations, variances of signal amplitudes or frequency correlations; a waveform information extraction unit configured to receive a radio signal and calculate a waveform feature based on the waveform feature information, the waveform feature indicating whether the received radio signal includes the radio signal transmitted from the other radio station; and a radio resource parameter determination unit configured to determine whether signal transmission from the radio station is available by comparing a waveform feature threshold with the waveform feature calculated by the waveform information extraction unit and to specify a radio resource to be used for the signal transmission based on the frequency information, the waveform feature information and/or the calculated waveform feature; wherein the radio resource parameter determination unit comprises a quality estimation table including correspondence between a peak amount of a waveform feature and signal quality of a channel between the radio station and the other radio station, and the radio resource parameter determination unit is configured to estimate the signal quality of the channel based on the calculated waveform feature indicative of the waveform feature of the radio signal transmitted from the other radio station with reference to the quality estimation table to determine whether signal transmission from the radio station is available by determining whether a desired communication quality is achievable under a transmit power constraint for limiting interference caused to the other radio station to be below a predefined level and specify a radio resource to be used for the signal transmission.