Patent ID: 7209709

Claim:
A signal discrimination device, which is used in a mobile communications system for transmitting a radio signal from a first device to a second device, for determining whether the radio signal indicates first information or second information, comprising: a demodulation unit demodulating a received radio signal; a first threshold generation unit calculating a variance of voltage of the radio signal, and generating a first threshold to guarantee a predetermined probability of misdetection according to the calculated variance; a second threshold generation unit estimating a difference between a center voltage of a signal propagating the first information and a center voltage of a signal propagating the second information based on received power or received amplitude of the radio signal, and generating a second threshold to guarantee a predetermined probability of omitted detection according to the estimated value; a selection unit selecting one of the first threshold and the second threshold according to a communications environment; and a discrimination unit determining whether the radio signal indicates the first information or the second information based on a comparison result between an output of said demodulation unit and the selected threshold selected by said selection unit.