Vehicle-mounted interphone with same-frequency relay function

Abstract

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.

Description

technical field [0001] The invention relates to the technical field of vehicle-mounted walkie-talkies, in particular to a vehicle-mounted walkie-talkie with the same-frequency relay function. Background technique [0002] In the wireless intercom system, the repeater plays an extremely important role in increasing the communication distance and extending the coverage, and is an indispensable and important device in the wireless communication system. [0003] Existing repeaters usually work in the state of transmitting and receiving different frequencies. The system composition requires two machines for receiving and transmitting, one duplexer and at least one antenna, and two frequencies need to be applied for. This solution has some disadvantages: [0004] (1) The relay function realized by using the duplexer, because the bandwidth of the duplexer is very narrow, the frequency used is limited, and must be limited within the frequency bandwidth of the duplexer; [0005] (2...

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Problems solved by technology

[0005] (2) Using the relay function of dual antennas, the erected antennas must have strict requirements to achieve a certain degree of isolation between sending and receiving, which is often difficult to meet in actual use, resulting in interference between sending and receiving, affecting the communication distance;

[0006] (3) The inter-frequency relay function realized by using dual frequency points needs to apply for two frequencies when setting up, which increases the user's usage fee and also causes a waste of frequency resources

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