The invention discloses a vehicle-mounted interphone with a same-frequency
relay function. The vehicle-mounted interphone comprises an antenna port, a transceiving switch circuit, a receiving
frequency selection circuit, a power amplification circuit, a transmitting
radio frequency unit, a receiving
radio frequency unit, a digital
baseband unit, a coding and decoding unit, an external
clock circuit, a
microprocessor and a
power supply unit. According to the vehicle-mounted interphone, the limitation that two machines are respectively used for receiving and transmitting, a
duplexer and at leastone antenna are needed, and a traditional
relay station erection scheme of two frequencies needs to be applied in the past is solved, and the same-frequency
relay function is realized. According to the vehicle-mounted radio
station, the same-frequency relay function can be achieved only by matching one vehicle-mounted interphone with one antenna, compared with a traditional
pilot frequency relaystation, frequency resources are saved, purchase funds are saved. Meanwhile, frequency point selection is not limited by the frequency bandwidth of a
duplexer, operation is easy and convenient, and communication is efficient and guaranteed.