A vehicle-mounted intercom

Abstract

The utility model provides a vehicle-mounted interphone relates to interphone field, including receiving unit, amplitude demodulation unit, frequency demodulation unit, demodulation selection switch, microprocessor, frequency modulation unit, amplitude modulation unit, sending unit, microphone and loudspeaker, receiving unit output respectively with amplitude demodulation unit and frequency demodulation unit input end connection, amplitude demodulation unit and frequency demodulation unit output respectively with demodulation selection switch two input end connection, demodulation selection switch output and microprocessor's first analog -to -digital conversion port connection, microprocessor's first digital -to -analog conversion port is connected with loudspeaker, microphone is connected with microprocessor's second analog -to -digital conversion port, microprocessor's second digital -to -analog conversion port is connected with frequency modulation unit and amplitude modulation unit's input respectively, frequency modulation unit and amplitude modulation unit's output is connected with sending unit's input respectively. The utility model can simplify circuit, reduce cost and failure rate.

Description

Technical Field

[0001] This utility model relates to the field of walkie-talkies, and in particular to a vehicle-mounted walkie-talkie. Background Technology

[0002] Vehicle-mounted walkie-talkies are communication tools installed inside vehicles. Existing vehicle-mounted walkie-talkies require a baseband-based audio processor at the front of the speaker to remove unwanted audio and ensure call quality. They also need peripheral circuitry at the rear of the microphone, including an echo processing unit, microphone gain, audio processing unit, and VOX detection. Furthermore, switching between noise-canceled and non-noise-canceled frequencies requires a separate switching device and a dedicated noise-canceling module. This results in complex peripheral circuitry, higher costs, and a greater susceptibility to malfunctions. Summary of the Invention

[0003] The main purpose of this invention is to propose a vehicle-mounted walkie-talkie that can simplify the circuit, reduce costs, and lower the failure rate while retaining rich functions.

[0004] This utility model is achieved through the following technical solution: A vehicle-mounted walkie-talkie includes a receiving unit, an amplitude modulation (AM) demodulation unit, a frequency modulation (FM) demodulation unit, a demodulation selection switch, a microprocessor, an FM modulation unit, an AM modulation unit, a transmitting unit, a microphone, and a speaker. The output of the receiving unit is connected to the inputs of the AM and FM demodulation units, respectively. The outputs of the AM and FM demodulation units are connected to the two inputs of the demodulation selection switch, respectively. The output of the demodulation selection switch is connected to the first analog-to-digital converter (ADC) port of the microprocessor. The first ADC port of the microprocessor is connected to the speaker, and the microphone is connected to the second ADC port of the microprocessor. The second ADC port of the microprocessor is connected to the inputs of the FM and AM modulation units, respectively. The outputs of the FM and AM modulation units are connected to the inputs of the transmitting unit, respectively. During reception, a microprocessor processes the demodulated signal and outputs an analog signal for playback by the speaker. During transmission, a microprocessor processes the microphone data and outputs an analog signal, which is then modulated and transmitted. This eliminates the need for external circuitry that processes the signal in existing technologies, making the entire walkie-talkie circuit simpler and reducing costs. Because the circuit is simpler, the probability of malfunction is also reduced.

[0005] Furthermore, the microprocessor uses the KT0712 chip, which has comprehensive audio processing capabilities and can be matched with the modulation and demodulation units to achieve better signal processing results.

[0006] Furthermore, it also includes an antenna, a transceiver switch unit, a receive frequency selection unit, and a power amplifier unit. The receiving unit is formed by the antenna, the transceiver switch unit, and the receive frequency selection unit connected in sequence, and the transmitting unit is formed by the power amplifier unit, the transceiver switch unit, and the antenna connected in sequence.

[0007] Furthermore, the amplitude modulation and demodulation unit includes a detection circuit.

[0008] Furthermore, the frequency modulation and demodulation unit includes an intermediate frequency integrated circuit.

[0009] Furthermore, the frequency modulation unit includes a phase-locked loop circuit.

[0010] Furthermore, the amplitude modulation unit includes an automatic gain control circuit.

[0011] Furthermore, the demodulation selection switch is an analog electronic switch controlled by a microprocessor.

[0012] Furthermore, it also includes an audio amplifier, which includes a chip U300, whose input is connected to the first digital-to-analog converter port of the microprocessor and whose output is connected to a speaker. Attached Figure Description

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0014] Figure 1 This is a schematic diagram of the principle of this utility model.

[0015] The components include: 1. Antenna; 2. Transceiver switch unit; 3. Receiver frequency selection unit; 4. Amplitude modulation and demodulation unit; 5. Frequency modulation and demodulation unit; 6. Demodulation selection switch; 7. Microprocessor; 8. Audio amplifier; 9. Frequency modulation unit; 10. Amplitude modulation unit; 11. Power amplifier unit; 12. Microphone; and 13. Speaker. Detailed Implementation

[0016] The present invention will be further described below through specific embodiments.

[0017] like Figure 1As shown, the vehicle-mounted walkie-talkie includes an antenna 1, a transceiver switch unit 2, a receiver frequency selection unit 3, a power amplifier unit 11, an amplitude modulation demodulation unit 4, an frequency modulation demodulation unit 5, a demodulation selection switch 6, a microprocessor 7, a frequency modulation unit 9, an amplitude modulation unit 10, an audio amplifier 8, a microphone 12, and a speaker 13. The antenna 1, transceiver switch unit 2, and receiver frequency selection unit 3, connected sequentially, form the receiver unit. The output of the receiver unit is connected to the inputs of the amplitude modulation demodulation unit 4 and the frequency modulation demodulation unit 5, respectively. The outputs of the amplitude modulation demodulation unit 4 and the frequency modulation demodulation unit 5 are connected to the two inputs of the demodulation selection switch 6, respectively. The output of the demodulation selection switch 6 is connected to the microprocessor... The first analog-to-digital converter (ADC-L) port of the microprocessor 7 is connected to the input terminal of the audio amplifier 8. The output terminal of the audio amplifier 8 is connected to the speaker 13. The microphone 12 is connected to the second analog-to-digital converter (ADC-R) port of the microprocessor 7. The second digital-to-analog converter (DAC-L) port of the microprocessor 7 is connected to the input terminals of the frequency modulation unit 9 and the amplitude modulation unit 10, respectively. The output terminals of the frequency modulation unit 9 and the amplitude modulation unit 10 are connected to the input terminals of the transmitting unit, respectively. The transmitting unit is formed by the power amplifier unit 11, the transceiver switch unit 2, and the antenna 1 connected in sequence. Among them, the microprocessor 7 uses the KT0712 chip, which can realize a single-chip solution for audio signal processing. It only requires simple peripheral circuits to realize all functions from audio data acquisition, audio algorithm processing to analog audio output (such as volume adjustment, equalizer, dynamic range compression, delay compensation, echo, noise reduction, voice enhancement, sound effect simulation, etc.). This chip is existing technology.

[0018] In this embodiment, the transceiver switch unit 2 is used to put the walkie-talkie into a receiving or transmitting state. After the antenna 1 receives the carrier signal, the carrier signal enters the receiving frequency selection unit 3 after passing through the transceiver switch unit 2. In the receiving frequency selection unit 3, the carrier signal is filtered out of band, mixed, and amplified using a known intermediate frequency (IF) signal, and then undergoes a second frequency conversion to generate an IF signal. This IF signal is split into two paths and demodulated by the amplitude modulation demodulation unit 4 and the frequency modulation demodulation unit 5 respectively to obtain an AM demodulated signal and an FM demodulated signal. The microprocessor 7 controls the demodulation selection switch 6 to select either the AM demodulated signal or the FM demodulated signal to enter the microprocessor 7. The microprocessor 7 performs audio processing such as gain control, dynamic compression, filtering, and noise reduction on the input signal, and then converts it into an analog audio signal through the first analog-to-digital converter port and outputs it to the audio amplifier 8, where it is played by the speaker 13. During transmission, microphone 12 collects sound signals and converts them into audio signals, which are then input to microprocessor 7. Microprocessor 7 performs audio processing such as gain control, dynamic compression, filtering, noise reduction, and echo cancellation. AM modulation carrier signals and FM modulation carrier signals are then obtained using amplitude modulation unit 10 and frequency modulation unit 9, and transmitted via power amplifier, transceiver switch unit 2, and antenna 1. The local oscillator signal used for mixing in receiver frequency selection unit 3 originates from frequency modulation unit 9.

[0019] In this embodiment, the amplitude modulation (AM) demodulation unit 4 includes a detector circuit, the frequency modulation (FM) demodulation unit 5 includes an intermediate frequency integrated circuit, the frequency modulation (FM) modulation unit 9 includes a phase-locked loop (PLL) circuit, the AM modulation (AM) modulation unit 10 includes an automatic gain control (AGC) circuit, and the demodulation selection switch 6 is an analog electronic switch controlled by the microprocessor 7. The audio amplifier 8 includes a chip U300, whose input terminal is connected to the first digital-to-analog converter port of the microprocessor 7, and whose output terminal is connected to the speaker 13. More specifically, the specific circuits of the AM demodulation unit 4, FM demodulation unit 5, FM modulation unit 9, and AM modulation unit 10 are all existing technologies.

[0020] In this utility model, the terms "first," "second," and "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. The use of terms such as "upper," "lower," "left," "right," "front," and "rear" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings and is only for the convenience of describing this utility model, and does not indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, it should not be construed as a limitation on the scope of protection of this utility model. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0022] The above are merely specific embodiments of this utility model, but the design concept of this utility model is not limited thereto. Any non-substantial modifications made to this utility model using this concept shall be considered as an infringement of the protection scope of this utility model.

Claims

1. A vehicle-mounted walkie-talkie, characterized in that: The device includes a receiving unit, an amplitude modulation (AM) demodulation unit, a frequency modulation (FM) demodulation unit, a demodulation selection switch, a microprocessor, an FM modulation unit, an AM modulation unit, a transmitting unit, a microphone, and a speaker. The output of the receiving unit is connected to the inputs of the AM and FM demodulation units, respectively. The outputs of the AM and FM demodulation units are connected to the two inputs of the demodulation selection switch, respectively. The output of the demodulation selection switch is connected to the first analog-to-digital converter (ADC) port of the microprocessor. The first ADC port of the microprocessor is connected to the speaker, and the microphone is connected to the second ADC port of the microprocessor. The second ADC port of the microprocessor is connected to the inputs of the FM and AM modulation units, respectively. The outputs of the FM and AM modulation units are connected to the inputs of the transmitting unit, respectively.

2. The vehicle-mounted walkie-talkie according to claim 1, characterized in that: The microprocessor uses the KT0712 chip.

3. A vehicle-mounted walkie-talkie according to claim 2, characterized in that: It also includes an antenna, a transceiver switch unit, a receive frequency selection unit, and a power amplifier unit. The receiving unit is formed by the antenna, the transceiver switch unit, and the receive frequency selection unit connected in sequence, and the transmitting unit is formed by the power amplifier unit, the transceiver switch unit, and the antenna connected in sequence.

4. A vehicle-mounted walkie-talkie according to claim 1, 2, or 3, characterized in that: The amplitude modulation and demodulation unit includes a detection circuit.

5. A vehicle-mounted walkie-talkie according to claim 1, 2, or 3, characterized in that: The frequency modulation and demodulation unit includes an intermediate frequency integrated circuit.

6. A vehicle-mounted walkie-talkie according to claim 1, 2, or 3, characterized in that: The frequency modulation unit includes a phase-locked loop circuit.

7. A vehicle-mounted walkie-talkie according to claim 1, 2, or 3, characterized in that: The amplitude modulation unit includes an automatic gain control circuit.

8. A vehicle-mounted walkie-talkie according to claim 1, 2, or 3, characterized in that: The demodulation selection switch is an analog electronic switch controlled by a microprocessor.

9. A vehicle-mounted walkie-talkie according to claim 1, 2, or 3, characterized in that: It also includes an audio amplifier, which includes a chip U300, whose input is connected to the first digital-to-analog converter port of the microprocessor and whose output is connected to a speaker.

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