Signal receiving device, signal identification system and method

A signal receiving apparatus includes a first receiving circuit, a second receiving circuit, a third receiving circuit, and a light emitting device. The first receiving circuit is configured to receive a first electromagnetic wave and obtain a first signal according to the first electromagnetic wave, and the first electromagnetic wave is an electromagnetic wave generated by modulating the first signal to the first carrier wave. And the second receiving circuit is coupled to the first receiving circuit and is configured to amplify the amplitude of the first signal output by the first receiving circuit to obtain a second signal. And a third receiving circuit configured to receive the third signal and output a fourth signal. And the light-emitting device is coupled between the second receiving circuit and the third receiving circuit, and is configured to be in an off state when the second signal is the same as the fourth signal, and in a light-emitting state when the second signal is different from the fourth signal.