COMMUNICATION DEVICE

摘要

An S/N calculation circuit 12 to calculate the S/N ratio of a received signal, and an S/N comparison circuit 13 to compare the S/N calculated by the S/N calculation circuit 12 with a threshold Th are disposed, and a parameter setting circuit 14 controls the radiation state of a beam radiated from a transmission optical system 5 according to the result of the comparison performed by the S/N comparison circuit 13. As a result, even if the state of the propagation environment gets worse, degradation in the communication quality can be prevented and communicative stabilization can be achieved.

主权项

1. A communication device comprising:
a beam transmitter to radiate a beam toward a communication device which is a communications partner; a beam receiver to receive a beam coming from said communication device which is a communications partner; a signal demodulator to demodulate a received signal from said beam receiver to extract communication data piggybacked onto said beam; a signal to noise ratio calculator to calculate a signal to noise ratio of the received signal from said beam receiver; and a beam radiation state controller to control a radiation state of the beam radiated from said beam transmitter according to the signal to noise ratio calculated by said signal to noise ratio calculator, and, when there occurs a state in which the signal to noise ratio calculated by said signal to noise ratio calculator temporarily becomes lower than a preset threshold and then becomes higher than said threshold, enlarge a beam diameter or an angle of divergence of the beam radiated from said beam transmitter.