A communication system in which a signal is transferred includes a transmitter that transmits a signal, a receiver that receives a signal transmitted thereto, and an adaptive equalizer that generates a compensated signal by compensating degradation of the signal to be received by the receiver. The adaptive equalizer includes a signal compensating section that generates the compensated signal by passing therethrough the signal to be received by the receiver, a jitter measuring section that measures jitter of the compensated signal output from the signal compensating section, and an adjusting section that adjusts a characteristic of the signal compensating section so as to reduce the jitter of the compensated signal which is measured by the jitter measuring section.