A distance measurement system for transmitting and receiving a distance measurement signal including a phase detection signal between first and second devices and calculating a distance between the devices based on a phase detection result of the received phase detection signal includes a modulation circuit configured to generate the distance measurement signal including a modulated signal obtained by modulating an identification signal, a transmission circuit configured to transmit the distance measurement signal, a reception circuit configured to receive the distance measurement signal, a demodulation circuit configured to demodulate the modulated signal in the received distance measurement signal, and a control circuit configured to judge a restored state of the identification signal obtained from a demodulation result of the demodulation circuit.