WO2018188193A1

WO2018188193A1 - Automatic gain control device and method

Info

Publication number: WO2018188193A1
Application number: PCT/CN2017/089626
Authority: WO
Inventors: 朱钧; 王元鹏
Original assignee: 深圳思凯微电子有限公司
Priority date: 2017-04-11
Filing date: 2017-06-22
Publication date: 2018-10-18
Also published as: CN107086875B; CN107086875A

Abstract

The invention discloses an automatic gain control device. The invention further discloses an automatic gain control method. A new AGC circuit structure is designed for an in-band same-frequency wireless receiver. A close coupling multi-stage multipath AGC architecture is used for matching the signal quality, power change and dynamic range requirement at different stages. Respective characteristics of an analog signal and a digital signal are used for performing mutual calibration so that each signal can acquire the best demodulation performance. The close coupling multi-stage multipath AGC circuit structure designed by the invention can enable each signal, especially the digital signal demodulated by an IBOC receiver to realize the best signal to noise ratio; therefore, the multipath signals in same-frequency playing have the same transmission effect, namely, the consistent receiving quality and coverage.

Description

Automatic gain control device and method

Technical field

The present invention relates to the field of communications, and in particular, to an automatic gain control apparatus and method.

Background technique

In a wireless communication environment, since the wireless channel transmitting the radio frequency signal is a time-varying channel, various signal fading phenomena exist, and both communication parties may move or switch channels, so the radio frequency signal power received by the wireless receiver is Unpredictable, it will certainly fluctuate within a large range. When the signal source is very close or the signal transmission conditions are good, the receiver may receive a very strong signal. When the signal source is far away or the transmission conditions are not good, the receiver may receive a very weak signal. The signal power that the receiver may receive varies widely, that is, the dynamic range of the wireless signal is large.

In order to realize a large dynamic range wireless receiver, it is necessary to implement a large dynamic range automatic gain control circuit to adjust the signal gain of the receiver so that the signal power is stabilized near a desired value to minimize the influence of signal power variation. The receiver can stably demodulate the data. It is highly probable that the receiver will not be able to demodulate the signal properly until the automatic gain control circuit in the receiver has set the appropriate signal gain. Therefore, automatic gain control becomes an indispensable part of the communication system implementation.

The automatic gain control referred to as AGC is the automatic control of the gain of the signal, or power and amplitude. Generally, at the receiver end, the amplifier on the radio frequency module is controlled to adjust the power of the analog signal by detecting the received signal energy, or the amplitude of the sampled digital signal is adjusted to achieve signal power control.

The AGC circuit achieves the goal of signal power adjustment. One is to amplify the simulated RF signal to the optimal power quantized by the digital-to-analog converter, and the second is to ensure that the receiver has a large enough dynamic range to process signals of different intensities. Therefore, the AGC circuit can minimize the quantization noise introduced by the receiver analog-to-digital converter and provide the optimal signal-to-noise ratio for the demodulator to achieve the lowest bit error rate.

In the field of wireless digital audio broadcasting, HD Radio, CDRadio, CDR and other technologies The scheme allows the existing analog modulated signal and the new digital modulated signal to be broadcasted in the same frequency band through digital analog aliasing and simulcasting, that is, In Band On Channel (IBOC) technology. The biggest feature of IBOC technology is the smooth transition from traditional analog broadcast to digital broadcast without the need for new frequency resource allocation.

Such IBOC broadcast systems mix and transmit analog FM signals and digital OFDM modulated signals on the same frequency, these signals have different transmit powers, and the time-varying signal power ratio occurs due to the fading effect during wireless transmission, making IBOC Wireless receivers face significant challenges in signal separation and demodulation. In particular, the AGC circuit design structure of the existing wireless receiver is difficult to satisfy the optimal reception effect of the IBOC signal, and the multi-channel signal simultaneously broadcast cannot achieve the optimal reception signal-to-noise ratio at the same time. The multi-channel signals broadcasted at the same frequency have different receiving quality and coverage, which has a significant impact on the promotion of IBOC technology, engineering implementation complexity and market efficiency.

The above content is only used to assist in understanding the technical solutions of the present invention, and does not constitute an admission that the above is prior art.

DRAWINGS

1 is a schematic circuit diagram of an automatic gain control device according to the present invention;

2 is a schematic diagram of a first embodiment of an automatic gain control device according to the present invention;

3 is a schematic view showing a second embodiment of an automatic gain control device according to the present invention;

4 is a flow chart of an automatic gain control method according to the present invention;

5 is a flow chart of a first embodiment of an automatic gain control method according to the present invention;

FIG. 6 is a flow chart of a second embodiment of an automatic gain control method according to the present invention.

The implementation, functional features, and advantages of the present invention will be further described in conjunction with the embodiments.

detailed description

It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

1 is a schematic circuit diagram of an automatic gain control device according to the present invention. Referring to FIG. 1, the device includes:

a first AGC module 10, a signal separation module 20, a second AGC module 30, and a third AGC module 40;

The first AGC module 10 is configured to receive a mixed signal, perform gain control on the mixed signal according to a first gain value, and send the mixed signal that is subjected to gain control to the signal separation module 20;

It should be noted that, when the mixed signal is received, the received mixed signal may be received by the receiver by a mixed signal sent by the RF front end and the analog to digital converter, that is, by modulating and digital-to-analoging the original signal of the RF or baseband. To form a mixed signal; the received mixed signal may also be directly receiving an existing mixed signal. The mixed signal is a set including an analog amplitude modulated signal, a digital OFDM modulated signal, or a set of other signals including an analog amplitude modulated signal, an analog frequency modulated signal, a digital OFDM modulated signal, etc., and the present invention does not limit the mixed signal herein. .

It can be understood that the automatic gain control is an automatic control method that automatically adjusts the gain of the amplifying circuit with the signal strength. Automatic gain control is a type of limited output that uses an effective combination of linear amplification and compression amplification to adjust the output signal. When a weak signal is input, the linear amplifying circuit works to ensure the intensity of the output signal; when the input signal reaches a certain intensity, the compression amplifying circuit is activated to reduce the output amplitude. In other words, the AGC function can automatically control the magnitude of the gain by changing the input-output compression ratio. The AGC is subdivided into AGCi (input automatic gain control) and AGCo (output automatic gain control).

It should be noted that the hybrid signal is subjected to automatic gain control, wherein the automatic gain control includes an internal AGC implementation manner and an external AGC implementation manner, and an external AGC implementation manner or an internal AGC implementation manner is adopted according to the specific situation of the radio frequency front end; The AGC can be divided into two types according to the signal adjustment mode: an external AGC that regulates the external analog RF signal and an internal AGC that adjusts the internal digital sampled signal. The external AGC controls the variable gain amplifier of the RF module by calculating the power of the received signal, so that the RF module output signal falls within the optimal dynamic range of the analog-to-digital converter and remains stable. There is a digital domain to the analog domain. Feedback signal. The internal AGC calculates the gain adjustment coefficient of the received signal, and then multiplies the signal after the delay, so that the output signal falls within the optimal dynamic range of the signal demodulator and remains stable.

The signal separation module 20 is configured to separate the gain-controlled mixed signal, send the separated analog signal to the second AGC module 30, and send the separated digital signal to the third AGC. Module 40;

It should be noted that the process of separating the gain-controlled mixed signal includes: separating the mixed signal that has undergone gain control, and separately setting a subsequent AGC for the separated analog signal and the digital OFDM signal, that is, The second AGC module 30 and the third AGC module 40 further adjust the separated signal, wherein the second AGC module 30 is responsible for gain control of the analog signal, and the third AGC module 40 is responsible for performing gain on the digital signal. Control, of course, if there is another type of signal after the separation of the mixed signal, an AGC module corresponding to the type of signal is provided for gain control of the type signal.

The second AGC module 30 is configured to perform gain control on the analog signal according to a second gain value to obtain a gain analog signal;

The third AGC module 40 is configured to perform gain control on the digital signal according to a third gain value to obtain a gain digital signal;

The second AGC module 30 is further configured to adjust the first gain value according to the second power difference, and adjust the third gain value according to the second power difference, and the adjusted Sending a gain value to the first AGC module 10, and transmitting the adjusted third gain value to the third AGC module 40; the second power difference value is a second power estimation value according to the analog signal And a difference obtained by subtracting the second preset reference power value, wherein the second power estimation value is an average power value of the analog signal in the preset time period.

It can be understood that the modification of the first AGC module 10 and the third AGC module 40 by the second AGC module 30 means that the respective AGC circuits are mutually modified, that is, using analog signals and digital signals respectively. The characteristics are mutually calibrated so that each signal can obtain the best demodulation performance; the use of the digital signal demodulation result to correct the gain adjustment coefficient refers to demodulation of the digital signal by a demodulation device such as a demodulator. A corresponding digital signal demodulation result is obtained, and the gain adjustment coefficient is adjusted by the digital signal demodulation result. The gain adjustment coefficient has a decisive influence on the convergence speed and stability of the gain value. Large gain adjustment factor value makes AGC close The convergence speed is increased, and it can adapt to the rapidly changing dynamic receiving environment, but its stability is poor, and it is more susceptible to noise signals, resulting in significant jitter of the gain-adjusted signal; smaller gain adjustment coefficient values can make the signal jitter very small, but The convergence speed is slow and it is not suitable for the fast changing dynamic receiving environment. To this end, the scheme adopts a tight coupling method to make each AGC circuit mutually correct, and uses the digital signal demodulation result to correct the gain adjustment coefficient, so that each AGC can work in an optimal state.

Correspondingly, the second AGC module 30 adjusts the first gain value according to the second power difference by:

G _next1 =G ₁ +α ₁ ·ΔP ₁ +β ₁ ·ΔP ₂

Where G _next1 is the adjusted first gain value, G ₁ is the first gain value, ΔP ₁ is a first power difference value, and the first power difference value is first according to the mixed signal And a difference between the power estimation value and the first preset reference power value, wherein the first power estimation value is an average power value of the mixed signal in a preset time period; and ΔP ₂ is the second power difference value , α ₁ and β ₁ are preset gain adjustment coefficients adapted to the first AGC module.

It should be noted that the first AGC module 10 is corrected by using the calculation result of the separated second AGC module 30. Because the analog FM signal is a constant envelope signal, the tracking of the signal strength is more accurate.

α ₁ and β ₁ is adapted to the predetermined gain adjustment coefficient of the first AGC module 10 may set an appropriate value is determined according to the specific system.

Correspondingly, the second AGC module 30 adjusts the third gain value according to the second power difference by:

G _next3 =G ₃ +α ₃ ·ΔP ₃ +β ₃ ·ΔP ₂

Where G _next3 is the adjusted third gain value, G ₃ is the third gain value, ΔP ₃ is the third power difference value, and the third power difference value is the third according to the digital signal. a difference obtained by subtracting the power estimated value from a third preset reference power value, the third power estimated value being an average power value of the digital signal in a preset time period; ΔP ₂ being the second power difference value , α ₃ and β ₃ are preset gain adjustment coefficients adapted to the third AGC module 40.

It can be understood that the third AGC module 40 is modified by using the calculation result of the separated second AGC module 30. Because the digital signal power in the digital-analog mixed signal is much lower than the analog frequency modulated signal, in the high-noise environment, the data input by the third AGC module 40 contains a large proportion of noise components, so that the signal power estimation is inaccurate. The data input by the second AGC module 30 is a frequency modulated signal sample, and has a high signal to noise ratio, so the calculation result can be used to correct the third AGC module 40.

It should be noted that the power difference is a difference obtained by subtracting the power estimation value from the preset reference power value, where the power estimation value is an average power value of the signal in the preset time period, and is calculated in a preset time period. The average power of the N sampled signals s(i) is calculated as follows:

Where P _est is the power estimation value, N is the tracking and control period length of the AGC, and s(i) is the sampling signal.

The current gain value is adjusted by using a power difference value, where the power difference value is a difference between the power estimation value and a preset reference power value, and the calculation formula is as follows:

ΔP=P _ref -P _est

Where ΔP is the power difference value, P _ref is the preset reference power value, and P _est is the power estimation value.

2 is a schematic diagram of a first embodiment of an automatic gain control device according to the present invention, based on the content shown in FIG. 1, referring to FIG. 2, the device further includes: a demodulator module 50;

The demodulator module 50 is configured to receive a gain digital signal sent by the third AGC module 40, and demodulate the gain digital signal;

In a specific implementation, a demodulator module may be further disposed after the second AGC module 30, for receiving the gain digital signal sent by the third AGC module 40, and demodulating the gain digital signal; Of course, if the separated mixed signal has other types of signals besides the analog signal and the digital signal, a demodulator module can be correspondingly reset for demodulating the type of signal to restore the type of signal to The signal capable of directly performing the communication service is not limited by the present invention;

The demodulator module 50 is further configured to modify α ₃ and β ₃ of the third AGC module 40 according to a signal to noise ratio SNR value of the demodulator module 50, and receive the third AGC module. 40. The modified gain digital signal demodulates the corrected gain digital signal.

The demodulator module 50 is further configured to: when the SNR value of the demodulator module 50 is less than a preset threshold, increase the α ₃ and reduce the β ₃ ; when the demodulator When the SNR value of the module 50 is greater than or equal to a preset threshold, the α ₃ is turned down and the β _{3 is} turned up.

It should be noted that the gain adjustment coefficient of the third AGC module 40 is corrected according to the SNR estimation result of the demodulator module 50. The SNR estimation result of the demodulator module 50 indicates the noise specific gravity of the input data of the third AGC module 40. When the SNR value of the demodulator module 50 is less than a preset threshold, that is, the SNR value is high, indicating that the noise specific gravity is small, and accordingly, the α _{3 is} adjusted to be large, and the β _{3 is} adjusted to be small; When the SNR value of the module 50 is greater than or equal to the preset threshold, that is, the SNR value is low, indicating that the noise ratio is significant, and accordingly, the α _{3 is} adjusted to be smaller than the β ₃ ; α ₃ and β ₃ are adapted to the The preset gain adjustment coefficient of the third AGC module 40 can be dynamically adjusted.

3 is a schematic diagram of a second embodiment of an automatic gain control device according to the present invention. Based on the content shown in FIG. 2, referring to FIG. 3, the device further includes: a radio frequency front end 01 and an analog to digital converter 02;

The third AGC module 40 is configured to perform gain control on the digital signal according to a third gain value, obtain a gain digital signal, the second AGC module 30, and further configured to pair the first power according to the second power difference value. The gain value is adjusted, and the third gain value is adjusted according to the second power difference, and the adjusted first gain value is sent to the first AGC module 10, and the adjusted third gain value is sent. Up to the third AGC module 40; the second power difference is a difference obtained by subtracting a second power estimated value of the analog signal and a second preset reference power value, the second power estimated value It is the average power value of the analog signal in the preset time period.

In a specific implementation, a demodulator module may be further disposed after the second AGC module 30, for receiving the gain digital signal sent by the third AGC module 40, and demodulating the gain digital signal; Of course, if the separated mixed signal has other types of signals besides the analog signal and the digital signal, it can be reset accordingly. a demodulator module for demodulating the type of signal to restore the signal of the type to a signal capable of directly performing a communication service, which is not limited by the present invention;

The RF front end 01 is configured to receive an external signal by using a radio frequency or a baseband, and send the external signal to the analog to digital converter 02;

It should be noted that the radio frequency front end is composed of a power amplifier (PA), a filter, a duplexer, a radio frequency switch, a low noise amplifier, a receiver/transmitter, and the like. The power amplifier is responsible for amplifying the RF signal of the transmitting channel; the filter is responsible for filtering the transmitting and receiving signals; the duplexer is responsible for the duplex switching of the FDD system and the filtering of the RF signal of the receiving/transmitting channel; the RF switch is responsible for receiving and transmitting between the channels. Switching; low noise amplifier is mainly used for small signal amplification in the receiving channel; receiver/transmitter is used for frequency conversion and channel selection of RF signals.

The analog-to-digital converter 02 is configured to receive the external signal sent by the radio frequency front end 01, convert the external signal into a mixed signal by digital-analog, and send the mixed signal to the first AGC module. 10;

In a specific implementation, the analog RF signal is amplified to the optimal power quantized by the digital-to-analog converter to ensure that the receiver has a large dynamic range to process signals of different strengths, and the AGC circuit can minimize the analog-to-digital conversion of the receiver. The quantization noise introduced by the device provides the optimal signal-to-noise ratio for the demodulator to achieve the lowest bit error rate. In order to realize a large dynamic range wireless receiver, it is necessary to implement a large dynamic range automatic gain control circuit to adjust the receiver. The signal gain stabilizes the signal power near a desired value to minimize the effects of signal power variations, allowing the receiver to demodulate the data stably.

It should be understood that in a wireless communication environment, due to the wireless signal transmitting the radio frequency signal The channel is a time-varying channel, and there are various signal fading phenomena, and the two communicating parties may move or switch channels. Therefore, the power of the RF signal received by the wireless receiver is unpredictable and must be in a large range. Internal fluctuations. When the signal source is very close or the signal transmission conditions are good, the receiver may receive a very strong signal. When the signal source is far away or the transmission conditions are not good, the receiver may receive a very weak signal. The signal power that the receiver may receive varies widely, that is, the dynamic range of the wireless signal is large.

It can be understood that the fading phenomenon includes slow fading and fast fading, which refers to loss due to a shadow effect caused by blocking of a building or a hill or the like on a radio wave transmission path. The fast fading refers to a phenomenon in which multipath propagation signals caused by scatterers (topography, features, moving objects, etc.) in the vicinity of the mobile station are superimposed at the receiving point, causing a rapid fluctuation of the received signal.

4 is a flow chart of an automatic gain control method according to the present invention. Referring to FIG. 4, the method includes:

S1, the first AGC module receives the mixed signal, performs gain control on the mixed signal according to the first gain value, and sends the mixed signal that is subjected to the gain control to the signal separation module;

S2, the signal separation module separates the gain-controlled mixed signal, sends the separated analog signal to the second AGC module, and transmits the separated digital signal to the third AGC module;

S3. The second AGC module performs gain control on the analog signal according to a second gain value to obtain a gain analog signal.

S4. The third AGC module performs gain control on the digital signal according to a third gain value to obtain a gain digital signal.

S5. The second AGC module adjusts the first gain value according to the second power difference, and adjusts the third gain value according to the second power difference, and adjusts the first gain value. Sending to the first AGC module, sending the adjusted third gain value to the third AGC module; the second power difference is a second power estimation value and a second preset according to the analog signal The reference power value is subtracted to obtain a difference, and the second power estimation value is an average power value of the analog signal in a preset time period.

Corresponding description of this embodiment, in order to avoid redundancy, refer to the corresponding description corresponding to FIG.

FIG. 5 is a block diagram of a first embodiment of an automatic gain control method according to the present invention. Based on the content shown in FIG. 4, referring to FIG. 5, the method includes:

S6. The demodulator module receives the gain digital signal sent by the third AGC module, and demodulates the gain digital signal.

S7. The demodulator module corrects α ₃ and β ₃ of the third AGC module according to a signal to noise ratio SNR value of the demodulator module, and receives the modified gain number of the third AGC module. a signal that demodulates the modified gain digital signal.

S8. The demodulator module increases the α ₃ and reduces the β ₃ when the SNR value of the demodulator module is less than a preset threshold; when the SNR value of the demodulator module When greater than or equal to the preset threshold, the α ₃ is turned down and the β _{3 is} turned up.

Corresponding description of this embodiment, in order to avoid redundancy, refer to the corresponding description corresponding to FIG. 2.

6 is a block diagram of a second embodiment of an automatic gain control method according to the present invention. Based on the content shown in FIG. 5, referring to FIG. 6, the method includes:

Before the step S1, the method further includes:

S01. The RF front end is configured to receive an external signal by using a radio frequency or a baseband, and send the external signal to an analog to digital converter;

S02. The analog-to-digital converter receives the external signal sent by the radio frequency front end, and the The external signal is digital-to-analog converted into a mixed signal, and the mixed signal is sent to the first AGC module;

It is to be understood that the term "comprises", "comprising", or any other variants thereof, is intended to encompass a non-exclusive inclusion, such that a process, method, article, or It also includes other elements that are not explicitly listed, or elements that are inherent to such a process, method, item, or system. An element defined by the phrase "comprising a ..." does not exclude the presence of additional equivalent elements in a process, method, article, or system that includes the element, without further limitation.

The serial numbers of the embodiments of the present invention are merely for the description, and do not represent the advantages and disadvantages of the embodiments.

Through the description of the above embodiments, those skilled in the art can clearly understand that the foregoing embodiment method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be through hardware, but in many cases, the former is better. Implementation. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a storage medium (such as ROM/RAM, disk, The optical disc includes a number of instructions for causing a terminal device (which may be a cell phone, a computer, a server, an air conditioner, or a network device, etc.) to perform the methods described in various embodiments of the present invention.

The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformations made by the description of the present invention and the drawings are directly or indirectly applied to other related technical fields. The same is included in the scope of patent protection of the present invention.

Claims

An apparatus for automatic gain control, the apparatus comprising: a first AGC module, a signal separation module, a second AGC module, and a third AGC module;

The first AGC module is configured to receive a mixed signal, perform gain control on the mixed signal according to a first gain value, and send the mixed signal that is subjected to gain control to a signal separation module;

The signal separation module is configured to perform the separation of the gain-controlled mixed signal, send the separated analog signal to the second AGC module, and send the separated digital signal to the third AGC module;

The second AGC module is configured to perform gain control on the analog signal according to a second gain value to obtain a gain analog signal;

The third AGC module is configured to perform gain control on the digital signal according to a third gain value to obtain a gain digital signal;

The second AGC module is further configured to adjust the first gain value according to a second power difference, and adjust the third gain value according to the second power difference, and adjust the first Sending a gain value to the first AGC module, and transmitting the adjusted third gain value to the third AGC module; the second power difference value is a second power estimation value according to the analog signal, and a second The difference between the preset reference power values is subtracted, and the second power estimated value is an average power value of the analog signal in the preset time period.
The apparatus according to claim 1, wherein said second AGC module adjusts said first gain value according to said second power difference value by:

G next1 =G 1 +α 1 ·ΔP 1 +β 1 ·ΔP 2

Where G next1 is the adjusted first gain value, G 1 is the first gain value, ΔP 1 is a first power difference value, and the first power difference value is first according to the mixed signal And a difference between the power estimation value and the first preset reference power value, wherein the first power estimation value is an average power value of the mixed signal in a preset time period; and ΔP 2 is the second power difference value , α 1 and β 1 are preset gain adjustment coefficients adapted to the first AGC module.
The apparatus according to claim 1, wherein said second AGC module adjusts said third gain value according to said second power difference value by:

G next3 =G 3 +α 3 ·ΔP 3 +β 3 ·ΔP 2

Where G next3 is the adjusted third gain value, G 3 is the third gain value, ΔP 3 is the third power difference value, and the third power difference value is the third according to the digital signal. a difference obtained by subtracting the power estimated value from a third preset reference power value, the third power estimated value being an average power value of the digital signal in a preset time period; ΔP 2 being the second power difference value , α 3 and β 3 are preset gain adjustment coefficients adapted to the third AGC module.
The apparatus according to claim 3, wherein said apparatus further comprises: a demodulator module, said demodulator module configured to receive a gain digital signal transmitted by said third AGC module, said gain Digital signal is demodulated;

The demodulator module is further configured to modify α 3 and β 3 of the third AGC module according to a signal to noise ratio SNR value of the demodulator module, and receive the corrected third AGC module. The digital signal is amplified to demodulate the modified gain digital signal.
The apparatus according to claim 4, wherein the demodulator module is further configured to: when the SNR value of the demodulator module is less than a preset threshold, increase the α 3 and β 3 is small; when the SNR value of the demodulator module is greater than or equal to a preset threshold, the α 3 is turned down and the β 3 is turned up.
The device of claim 1 further comprising: a radio frequency front end and an analog to digital converter;

The radio frequency front end is configured to receive an external signal by using a radio frequency or a baseband, and send the external signal to the analog to digital converter;

The analog-to-digital converter is configured to receive the external signal sent by the radio frequency front end, The external signal is digital-to-analog converted to a mixed signal and the mixed signal is sent to the first AGC module.
A method of automatic gain control, the method comprising:

The first AGC module receives the mixed signal, performs gain control on the mixed signal according to the first gain value, and sends the mixed signal that is subjected to the gain control to the signal separation module;

The signal separation module separates the gain-controlled mixed signal, sends the separated analog signal to the second AGC module, and transmits the separated digital signal to the third AGC module;

The second AGC module performs gain control on the analog signal according to a second gain value to obtain a gain analog signal;

The third AGC module performs gain control on the digital signal according to a third gain value to obtain a gain digital signal;

The second AGC module adjusts the first gain value according to the second power difference, adjusts the third gain value according to the second power difference, and sends the adjusted first gain value to Transmitting, by the first AGC module, the adjusted third gain value to the third AGC module; the second power difference value is a second power estimation value and a second preset reference power according to the analog signal The value is subtracted from the difference, and the second power estimate is an average power value of the analog signal within a preset time period.
The method according to claim 7, wherein the second AGC module adjusts the first gain value according to the second power difference by:

G next1 =G 1 +α 1 ·ΔP 1 +β 1 ·ΔP 2

Where G next1 is the adjusted first gain value, G 1 is the first gain value, ΔP 1 is a first power difference value, and the first power difference value is first according to the mixed signal And a difference between the power estimation value and the first preset reference power value, wherein the first power estimation value is an average power value of the mixed signal in a preset time period; and ΔP 2 is the second power difference value , α 1 and β 1 are preset gain adjustment coefficients adapted to the first AGC module.
The method according to claim 7, wherein the second AGC module adjusts the third gain value according to the second power difference by:

G next3 =G 3 +α 3 ·ΔP 3 +β 3 ·ΔP 2

Where G next3 is the adjusted third gain value, G 3 is the third gain value, ΔP 3 is the third power difference value, and the third power difference value is the third according to the digital signal. a difference obtained by subtracting the power estimated value from a third preset reference power value, the third power estimated value being an average power value of the digital signal in a preset time period; ΔP 2 being the second power difference value , α 3 and β 3 are preset gain adjustment coefficients adapted to the third AGC module.
The method according to claim 9, wherein the demodulator module receives the gain digital signal transmitted by the third AGC module, and demodulates the gain digital signal;

Correcting α 3 and β 3 of the third AGC module according to a signal to noise ratio SNR value of the demodulator module, and receiving the modified gain digital signal of the third AGC module, and the corrected The gain digital signal is demodulated.
The method of claim 10, wherein when said SNR value of said demodulator module is less than a predetermined threshold, said α 3 is increased and said β 3 is decreased; when said demodulating When the SNR value of the module is greater than or equal to a preset threshold, the α 3 is turned down and the β 3 is turned up.
The method according to claim 7, wherein said first AGC module receives a mixed signal, performs gain control on said mixed signal according to a first gain value, and transmits a mixed signal subjected to gain control to a signal separation module Previously, the method further includes:

The RF front end uses an RF or baseband to receive an external signal and sends the external signal to an analog to digital converter;

The analog to digital converter receives the external signal sent by the radio frequency front end, converts the external signal into a mixed signal by digital-analog, and sends the mixed signal to the first AGC module.