A vehicle-mounted walkie-talkie with same-frequency repeater function

Abstract

The invention discloses a vehicle-mounted intercom with the same-frequency relay function, which includes an antenna port, a transceiver 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 codec unit, External clock circuit, microprocessor and power supply unit. This vehicle-mounted walkie-talkie solves the limitations of the traditional relay station erection scheme that requires two machines for receiving and transmitting, a duplexer and at least one antenna, and needs to apply for two frequencies in the past, and realizes the same frequency relay Function. This car radio is simplified to only need a car walkie-talkie with an antenna to realize the same-frequency repeater function. Compared with the traditional different-frequency repeater, it saves frequency resources and purchase funds. At the same time, the frequency point selection does not need to be restricted. Due to the limitation of the frequency bandwidth of the duplexer, the operation is simple and the communication efficiency is 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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