Voice signal adjusting method based on AGC circuit

Abstract

The application discloses a voice signal adjusting method based on an AGC circuit, which comprises the following steps: inputting several different intensity signals through the AGC circuit, and recording the corresponding table in which the AGC circuit can be adjusted to a reasonable state; when the AGC circuit receives a voice signal, adjusting the AGC driving voltage according to the intensity of the input signal and the table established in step S1, so that the AGC circuit adjusts the voice signal to a reasonable state. The application adjusts the voice signal by using the AGC circuit, and realizes fast adjustment based on the look-up table method, so that the adjustment effect is good and the adjustment speed is fast. Compared with the parameter method of the traditional AGC voltage regulating amplifier, the application adopts the AGC driving voltage to adjust the amplification gain of the AGC circuit, which is more flexible and rapid.

Description

Technical Field

[0001] This invention belongs to the field of signal processing technology, specifically relating to a voice signal adjustment method based on an AGC circuit. Background Technology

[0002] With the rapid development of industries such as microelectronics, computer network technology, and communication technology, automatic gain control circuits are becoming increasingly well-known and widely used in various fields.

[0003] The output signal of a receiver depends on the input signal and the receiver's gain. Due to various reasons, the input signal to a receiver often varies greatly, ranging from one or tens of microvolts for weak signals to hundreds of millivolts for strong signals. The difference between the strongest and weakest signals can be tens of decibels. This range of variation is called the receiver's dynamic range.

[0004] Many factors affect the input signal of a receiver, such as the power of the transmitter, the distance between the receiver and the transmitter, changes in the propagation conditions during signal propagation, changes in the receiver environment, and the impact of man-made noise on the receiver.

[0005] In handheld radio applications, the following three situations may occur:

[0006] Scenario 1: The volume is too low, making it impossible to discern specific speech information; we may even need to press our faces against the speaker and furrow our brows to "listen." This could be due to the speaker being too far from the microphone, or the microphone's volume being too low.

[0007] Scenario 2: The volume is too loud, causing our ears to suffer, forcing us to keep our distance from the speaker. This could be because the speaker is too close to the microphone or is speaking too forcefully.

[0008] Scenario 3: The volume fluctuates. The two problems mentioned above may exist in a single audio clip. The fluctuating volume, sometimes loud and sometimes soft, is undoubtedly a "torture" for the listener. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention proposes a voice signal adjustment method based on an AGC circuit.

[0010] To achieve the above objectives, the technical solution of the present invention is as follows:

[0011] This invention discloses a voice signal adjustment method based on an AGC circuit, comprising:

[0012] Step S1: Pass several input signals of different strengths through the AGC circuit, and record the signals that the AGC circuit can adjust to a reasonable state, and establish a corresponding table;

[0013] Step S2: When the AGC circuit receives the voice signal, it adjusts the AGC drive voltage according to the strength of the input signal and the table established in step S1, so that the AGC circuit adjusts the voice signal to a reasonable state.

[0014] Based on the above technical solution, the following improvements can be made:

[0015] As a preferred embodiment, step S1 includes:

[0016] Step S1.1: Determine the range of the input signal for the AGC circuit;

[0017] Step S1.2: Within the dynamic range of the AGC circuit, after the input signal passes through the AGC circuit, the corresponding RSSI value is obtained. At this time, the AGC drive voltage is the initial value.

[0018] Step S1.3: Adjust the AGC drive voltage and record the corresponding AGC drive voltage when the AGC circuit adjusts the input signal of this strength to a reasonable state;

[0019] Step S1.4: Repeat steps S1.2-S1.3 to create a table of AGC drive voltages corresponding to input signals of different intensities.

[0020] As a preferred option, step S1.4 establishes an RSSI value-AGC drive voltage table, which represents the RSSI value of input signals of different intensities and the corresponding AGC drive voltage adjusted to a reasonable state.

[0021] As a preferred embodiment, step S2 includes:

[0022] Step S2.1: When the AGC circuit receives a voice signal, it makes an adjustment at regular intervals. The specific adjustments include:

[0023] When the RSSI value of the voice signal is too high, check the RSSI value - AGC drive voltage table and adjust the AGC drive voltage downward.

[0024] When the RSSI value of the voice signal is too low, check the RSSI value - AGC drive voltage table and adjust the AGC drive voltage upwards.

[0025] When the voice signal is within a reasonable range, the AGC drive voltage is not adjusted.

[0026] Step S2.2: After repeating step S2.1 multiple times, the AGC circuit enters a steady state;

[0027] Step S2.3: After entering steady state, the voltage is adjusted again only when the RSSI value of the voice signal is not within a reasonable range after multiple consecutive monitoring, until the voice signal reception ends.

[0028] As a preferred option, the AGC drive voltage is restored to its initial value after the voice signal reception ends.

[0029] As a preferred embodiment, the input signal and / or voice signal are adjusted by at least two stages of AGC circuits arranged in series.

[0030] As a preferred embodiment, the gain of the AGC circuit is adjusted by the AGC drive voltage, which is obtained through the following steps;

[0031] Step A1: The microcontroller's timer channel outputs a PWM wave;

[0032] Step A2: The PWM wave is filtered into DC voltage through a filter network;

[0033] Step A3: The DC voltage is amplified by an operational amplifier;

[0034] Step A4: The amplified voltage is divided by resistors to obtain the AGC drive voltage, which is supplied to the AGC circuit to control the amplification factor.

[0035] As a preferred approach, the RSSI value of the input signal is obtained through the following steps;

[0036] Step B1: The input signal enters through the antenna;

[0037] Step B2: After the input signal passes through the AGC circuit, it is then mixed and filtered to obtain the intermediate frequency signal;

[0038] Step B3: The microcontroller's AD module samples the intermediate frequency signal and calculates the signal strength RSSI value at this time.

[0039] As a preferred embodiment, step B3 includes:

[0040] Step B3.1: The microcontroller's AD module samples the intermediate frequency signal;

[0041] Step B3.2: Obtain the baseband AM modulated signal through an intermediate frequency filter;

[0042] Step B3.3: Calculate the RSSI value of the baseband AM modulated signal at regular intervals, smooth each RSSI value, and obtain the final signal strength RSSI value.

[0043] This invention discloses a voice signal adjustment method based on an AGC circuit, which has the following characteristics:

[0044] Beneficial effects:

[0045] First, this invention utilizes an AGC circuit to adjust the voice signal, and achieves rapid adjustment based on a lookup table method, resulting in good adjustment effect and fast adjustment speed.

[0046] Secondly, compared to the parametric method of traditional AGC voltage-regulated amplifiers, this invention uses the AGC drive voltage to adjust the amplification gain of the AGC circuit, which is more flexible and rapid. Furthermore, compared to the shortcomings of traditional methods, such as poor linearity and a small dynamic range of gain, this invention improves the linear range of the gain and increases the dynamic range of gain by connecting at least two stages of AGC circuit in series. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A flowchart of a voice signal adjustment method provided in an embodiment of the present invention.

[0049] Figure 2 This is a block diagram of a voice signal adjustment method provided in an embodiment of the present invention. Detailed Implementation

[0050] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Furthermore, the expression "includes" is an "open-ended" expression, which means only that there is a corresponding component or step, and should not be interpreted as excluding additional components or steps.

[0053] To achieve the objectives of this invention, some embodiments of a voice signal adjustment method based on an AGC circuit, such as... Figure 1 As shown, the speech signal adjustment method includes:

[0054] Step S1: Pass several input signals of different strengths through the AGC circuit, and record the signals that the AGC circuit can adjust to a reasonable state, and establish a corresponding table;

[0055] Step S2: When the AGC circuit receives a voice signal, it adjusts the AGC drive voltage according to the strength of the input signal and the table established in step S1, so that the AGC circuit adjusts the input voice signal to a reasonable state before outputting it.

[0056] The following is a detailed explanation of each step.

[0057] Furthermore, step S1 includes:

[0058] Step S1.1: Determine the range of the input signal for the AGC circuit;

[0059] Step S1.2: Within the dynamic range of the AGC circuit, after the input signal passes through the AGC circuit, the corresponding RSSI value is obtained. At this time, the AGC drive voltage is the default maximum value.

[0060] Step S1.3: Adjust the AGC drive voltage and record the corresponding AGC drive voltage when the AGC circuit adjusts the input signal of this strength to a reasonable state;

[0061] Step S1.4: Repeat steps S1.2-S1.3 to create a table of AGC drive voltages corresponding to input signals of different intensities.

[0062] Among them: Step S1.4 establishes an RSSI value-AGC drive voltage table, which represents the RSSI value of input signals of different intensities and the corresponding AGC drive voltage adjusted to a reasonable state.

[0063] Furthermore, step S2 includes:

[0064] Step S2.1: When the AGC circuit receives a voice signal, it makes an adjustment every 50ms. The specific adjustment includes:

[0065] When the RSSI value of the voice signal is too high, check the RSSI value - AGC drive voltage table and adjust the AGC drive voltage downward.

[0066] When the RSSI value of the voice signal is too low, check the RSSI value - AGC drive voltage table and adjust the AGC drive voltage upwards.

[0067] When the voice signal is within a reasonable range, the AGC drive voltage is not adjusted.

[0068] Step S2.2: After repeating step S2.1 three times, the AGC circuit enters a steady state;

[0069] Step S2.3: After entering steady state, the voltage is adjusted only once if the RSSI value of the voice signal is outside the reasonable range for ten consecutive monitoring cycles, until the voice signal reception ends.

[0070] After the voice signal reception ends, the AGC drive voltage returns to its default maximum value.

[0071] When no voice signal is received, the RSSI value is in the white noise range, and the AGC drive voltage is not adjusted.

[0072] The aforementioned input signals and voice signals are adjusted through a two-stage AGC circuit connected in series.

[0073] Furthermore, such as Figure 2 As shown, the gain of the AGC circuit is adjusted by the AGC drive voltage, which is obtained through the following steps;

[0074] Step A1: The microcontroller's timer channel outputs a PWM wave;

[0075] Step A2: The PWM wave is filtered into a DC voltage through a filter network. The DC voltage range is 0-3.3V. The magnitude of the DC voltage can be adjusted by adjusting the duty cycle of the PWM wave.

[0076] Step A3: The DC voltage is amplified by two times by an operational amplifier;

[0077] Step A4: The amplified voltage is divided by the resistor to obtain the AGC drive voltage, which is supplied to the gate of the transistor in the AGC circuit, thereby controlling the amplification factor.

[0078] Furthermore, the RSSI value of the input signal is obtained through the following steps;

[0079] Step B1: The input signal enters through the antenna;

[0080] Step B2: After the input signal passes through the AGC circuit, it is then mixed and filtered to obtain a 450KHz intermediate frequency signal;

[0081] Step B3: The microcontroller's AD module samples the intermediate frequency signal and calculates the signal strength RSSI value at this time.

[0082] The gain of the AGC circuit is adjusted based on the RSSI value to stabilize the output signal amplitude within a certain range. The AGC circuit gains maximum when the gate voltage of the transistor reaches its maximum. When the RSSI value is too low, the coefficient of the demodulated output signal, i.e., the digital amplification factor, is adjusted.

[0083] Step B3 further includes:

[0084] Step B3.1: The microcontroller's AD module samples the 450kHz intermediate frequency signal;

[0085] Step B3.2: Obtain the baseband AM modulated signal through an intermediate frequency filter;

[0086] Step B3.3: Calculate the RSSI value of the baseband AM modulated signal every 10ms. Put each RSSI value into an array of size 5 for smoothing to reduce the impact of AM signal energy fluctuations and obtain the final signal strength RSSI value.

[0087] This invention discloses a voice signal adjustment method based on an AGC circuit, which has the following characteristics:

[0088] Beneficial effects:

[0089] First, this invention utilizes an AGC circuit for voice signal adjustment, and achieves rapid adjustment based on a lookup table method, resulting in good adjustment effect and fast adjustment speed. When the voice signal is weak, the AGC circuit controls the receiver to have a higher gain; when the voice signal is strong, the AGC circuit controls the receiver to have a lower gain. Thus, when the strength of the received voice signal changes, the signal at the receiver's output remains essentially unchanged or constant.

[0090] Secondly, compared to the parametric method of traditional AGC voltage-regulated amplifiers, this invention uses the AGC drive voltage to adjust the amplification gain of the AGC circuit, which is more flexible and rapid. Furthermore, compared to the shortcomings of traditional methods, such as poor linearity and a small dynamic range of gain, this invention improves the linear range of the gain and increases the dynamic range of gain by connecting at least two stages of AGC circuit in series.

[0091] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A voice signal adjusting method based on an AGC circuit, characterized by, include: Step S1: Pass several input signals of different strengths through the AGC circuit, and record the signals that the AGC circuit can adjust to a reasonable state, and establish a corresponding table; Step S1 includes: Step S1.1: Determine the range of the input signal for the AGC circuit; Step S1.2: Within the dynamic range of the AGC circuit, after the input signal passes through the AGC circuit, the corresponding RSSI value is obtained. At this time, the AGC drive voltage is the initial value. Step S1.3: Adjust the AGC drive voltage and record the corresponding AGC drive voltage when the AGC circuit adjusts the input signal of this strength to a reasonable state; Step S1.4: Repeat steps S1.2-S1.3 to establish an RSSI value-AGC drive voltage table. This table represents the RSSI value of input signals of different intensities and the corresponding AGC drive voltage adjusted to a reasonable state. Step S2: When the AGC circuit receives a voice signal, it adjusts the AGC drive voltage according to the intensity of the input signal and the table established in step S1, so that the AGC circuit adjusts the voice signal to a reasonable state. Step S2 includes: Step S2.1: When the AGC circuit receives a voice signal, it makes an adjustment at regular intervals. The specific adjustments include: When the RSSI value of the voice signal is too high, check the RSSI value - AGC drive voltage table and adjust the AGC drive voltage downward. When the RSSI value of the voice signal is too low, check the RSSI value - AGC drive voltage table and adjust the AGC drive voltage upwards. When the voice signal is within a reasonable range, the AGC drive voltage is not adjusted. Step S2.2: After repeating step S2.1 multiple times, the AGC circuit enters a steady state; Step S2.3: After entering steady state, the voltage is adjusted again only when the RSSI value of the voice signal is not within a reasonable range after multiple consecutive monitoring, until the voice signal reception ends.

2. The voice signal adjustment method according to claim 1, characterized in that, After the voice signal reception ends, the AGC drive voltage returns to its initial value.

3. The voice signal adjusting method according to claim 1 or 2, characterized by, The input signal and / or voice signal are adjusted by at least two AGC circuits connected in series.

4. The voice signal adjusting method of claim 1 or 2, wherein, The gain of the AGC circuit is adjusted by the AGC drive voltage, which is obtained through the following steps; Step A1: The microcontroller's timer channel outputs a PWM wave; Step A2: The PWM wave is filtered into DC voltage through a filter network; Step A3: The DC voltage is amplified by an operational amplifier; Step A4: The amplified voltage is divided by resistors to obtain the AGC drive voltage, which is supplied to the AGC circuit to control the amplification factor.

5. The voice signal adjusting method of claim 4, characterized by, The RSSI value of the input signal is obtained through the following steps; Step B1: The input signal enters through the antenna; Step B2: After the input signal passes through the AGC circuit, it is then mixed and filtered to obtain the intermediate frequency signal; Step B3: The microcontroller's AD module samples the intermediate frequency signal and calculates the RSSI value of the signal strength at this time.

6. The voice signal adjusting method of claim 5, characterized by, Step B3 includes: Step B3.1: The microcontroller's AD module samples the intermediate frequency signal; Step B3.2: Obtain the baseband AM modulated signal through an intermediate frequency filter; Step B3.3: Calculate the RSSI value of the baseband AM modulated signal at regular intervals, smooth each RSSI value, and obtain the final signal strength RSSI value.

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