A controller having a wireless transmission interface is provided. The controller includes an amplifier, an analog-to-digital converter, a digital filter, a processor, and a radio frequency signal transceiver. The amplifier is coupled to the wireless transmission interface, and generates an amplification signal according to an input signal. The analog-to-digital converter is coupled to the amplifier, and configured to convert the amplification signal into a digital format. The digital filter is coupled to the analog-to-digital converter, and configured to filter the amplification signal in the digital format to generate a filtered signal. The processor is coupled to the digital filter, and configured to perform a calculation on the filtered signal to generate a calculation result. The radio frequency signal transceiver is coupled to the processor, and obtains received information according to the calculation result and the filtered signal.