Patent attributes
A channel search device is provided, which includes: a quasi-synchronization quadrature detector for outputting an I-axis signal and a Q-axis signal obtained by performing quasi-synchronization quadrature detection, based on the carrier frequency set value, on a PSK modulation signal; a timing reproducer for reproducing and outputting the I-axis signal and the Q-axis signal while correcting an error of the symbol rate set value; and a dispersion detector for detecting a dispersion between the amplitude of a symbol, comprising the I-axis signal and the Q-axis signal, and a reference amplitude. The channel search device monitors the above-described dispersion while varying the carrier frequency set value and the symbol rate set value, and judges that a channel of the symbol rate set value at the present time exists at the position of the carrier frequency set value when the size of the dispersion detected by the dispersion detector becomes an extremal value.
