CN116471656A - Automatic gain control method and device for monitoring receiver - Google Patents
Automatic gain control method and device for monitoring receiver Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/04—TPC
- H04W52/52—TPC using AGC [Automatic Gain Control] circuits or amplifiers
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
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- H04B1/16—Circuits
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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Abstract
The application provides a method and a device for controlling automatic gain of a monitoring receiver, wherein the device comprises the following steps: the digital control attenuator, the low noise amplifier, the preselect filter, the variable gain amplifier, the analog-to-digital converter, the digital average amplitude calculation module and the gain adjustment control module; the digital control attenuator is sequentially connected with the low noise amplifier, the preselection filter, the variable gain amplifier and the analog-to-digital converter; the output of the analog-to-digital converter is sequentially connected with a digital average amplitude calculation module and a gain adjustment control module; the output of the gain adjustment control module is respectively connected with the numerical control attenuator and the variable gain amplifier. The device provided by the application realizes automatic control of gain, effectively solves the problems that an analog automatic gain control circuit in the existing receiver is complex, digital feedback type automatic gain control performs gain control by logarithmic digital power, has high calculation complexity, only performs gain adjustment on a medium-frequency signal, and is not suitable for simultaneous receiving of broadband multiple signals.
Description
Technical Field
The present disclosure relates to the field of wireless communications technologies, and in particular, to a method and an apparatus for controlling automatic gain of a monitoring receiver.
Background
The monitoring receiver needs to receive all signals of the target frequency band, in which strong signals and weak signals may exist at the same time. For weak signals, a sufficient gain is required, and for strong signals, the gain cannot be too great, otherwise the ADC (Analog-to-Digital Converter) will be saturated, many nonlinear frequency components will be generated, and even the device will be burned out, so the receiver radio frequency link needs to be automatically gain controlled.
The goal of automatic gain control is to have the total rf signal output amplitude close to and well below the full scale of the ADC so that the strong and weak signals fall within the spurious free dynamic range of the ADC.
The conventional automatic gain control method mainly includes analog feedforward gain control (the circuit structure of which is shown in fig. 1), analog feedback gain control (the circuit structure of which is shown in fig. 2), and digital feedback gain control (the circuit structure of which is shown in fig. 3). Whether of the analog feed-forward or analog feedback type, additional rf detection circuitry is required, increasing rf circuitry size and cost. The existing digital feedback type gain control circuit is mainly used for a superheterodyne receiver, performs gain adjustment through digital logarithmic power, performs gain adjustment only on a medium-frequency signal, and is not suitable for an application scene of simultaneous receiving of a plurality of broadband signals.
Disclosure of Invention
In order to solve one of the above technical drawbacks, the present application provides a method and apparatus for controlling automatic gain of a monitoring receiver.
In a first aspect of the present application, there is provided an automatic gain control apparatus for a monitoring receiver, the apparatus comprising:
the digital control attenuator, the low noise amplifier, the preselect filter, the variable gain amplifier, the analog-to-digital converter, the digital average amplitude calculation module and the gain adjustment control module;
the digital control attenuator is sequentially connected with the low noise amplifier, the preselection filter, the variable gain amplifier and the analog-to-digital converter;
the output of the analog-to-digital converter is sequentially connected with a digital average amplitude calculation module and a gain adjustment control module;
the output of the gain adjustment control module is respectively connected with the numerical control attenuator and the variable gain amplifier.
Optionally, the digital control attenuator is a two-gear attenuator, 20dB attenuation and 0dB attenuation respectively, and the digital control attenuator defaults to 0dB attenuation.
Optionally, the fixed gain of the low noise amplifier is 20dB.
Optionally, the gain maximum adjustment value of the variable gain amplifier is 48dB.
Optionally, the sampling rate of the analog-to-digital converter is 245.76MHz.
In a second aspect of the present application, there is provided a method for monitoring automatic gain control of a receiver, the method being applied to the apparatus described in the first method, the method comprising:
the digital control attenuator attenuates the input broadband radio frequency signal according to a first gain control instruction of the gain adjustment control module;
amplifying the attenuated signal by a low noise amplifier;
the preselection filter filters the amplified signals to obtain signals in a target frequency band;
the variable gain amplifier carries out gain adjustment on signals in a target frequency band according to a second gain control instruction of the gain adjustment control module;
the analog-to-digital converter performs analog-to-digital conversion on the signal after gain adjustment;
the digital average amplitude calculation module calculates the average value of the analog-to-digital converted signal;
the gain adjustment control module determines a first gain control instruction and a second gain control instruction according to the relation between the average value and a preset threshold value.
Optionally, the digital average amplitude calculation module calculates an average value of the analog-to-digital converted signal, including:
the digital average amplitude calculation module calculates the average value of the analog-to-digital converted signal in each preset time interval;
the digital average amplitude calculation module calculates an average value of a preset number of output average values.
Optionally, the gain adjustment control module determines the first gain control instruction and the second gain control instruction according to a relationship between the average value and a preset threshold value, including:
gain value gain_value is obtained, and the initial value of gain_value is the maximum gain;
adjusting the gain_value according to the relation between the average value and a preset threshold value;
and determining a first gain control instruction and a second gain control instruction according to the current gain_value.
Optionally, the preset threshold value includes a preset high threshold value, a preset middle threshold value, and a preset low threshold value;
adjusting the gain_value according to the relation between the average value and a preset threshold value, including:
if the average value is greater than or equal to a preset high threshold, gain_value=gain_value-first step size;
if the average value is less than or equal to the preset low threshold value, gain_value=maximum gain;
if the average value is greater than the preset low threshold value and less than the preset medium threshold value, gain_value=gain_value+second step length;
if the average value is greater than or equal to the preset middle threshold value and less than the preset high threshold value, gain_value=gain_value.
Optionally, the numerical control attenuator is a two-gear attenuator, and the two attenuations are respectively 20dB attenuation and 0dB attenuation;
determining a first gain control instruction and a second gain control instruction according to the current gain_value, including:
if the current gain_value is larger than the maximum gain, setting the gain_value as the maximum gain, and determining that the first gain control instruction is attenuated by 0dB and the second gain control instruction is a gain maximum adjustment value of the gain adjustment variable gain amplifier;
if the current gain_value is not greater than the maximum gain but greater than or equal to the gain maximum adjustment value of the variable gain amplifier, determining that the first gain control instruction is attenuation 0dB and the second gain control instruction is gain adjustment gain_value- (maximum gain-gain maximum adjustment value of the variable gain amplifier);
if the current gain value is smaller than the gain maximum adjustment value of the variable gain amplifier, the first gain control instruction is determined to be attenuated by 20dB and the second gain control instruction is determined to be gain adjustment gain value.
The application provides a method and a device for controlling automatic gain of a monitoring receiver, wherein the device comprises the following steps: the digital control attenuator, the low noise amplifier, the preselect filter, the variable gain amplifier, the analog-to-digital converter, the digital average amplitude calculation module and the gain adjustment control module; the digital control attenuator is sequentially connected with the low noise amplifier, the preselection filter, the variable gain amplifier and the analog-to-digital converter; the output of the analog-to-digital converter is sequentially connected with a digital average amplitude calculation module and a gain adjustment control module; the output of the gain adjustment control module is respectively connected with the numerical control attenuator and the variable gain amplifier. The device provided by the application realizes automatic control of gain, effectively solves the problems that an analog automatic gain control circuit in the existing receiver is complex, digital feedback type automatic gain control performs gain control by logarithmic digital power, has high calculation complexity, only performs gain adjustment on a medium-frequency signal, and is not suitable for simultaneous receiving of broadband multiple signals.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:
FIG. 1 is a schematic diagram of a conventional receiver analog feedforward type automatic gain circuit;
FIG. 2 is a schematic diagram of a conventional receiver analog feedback type automatic gain circuit;
FIG. 3 is a schematic diagram of a digital feedback type automatic gain circuit of a conventional receiver;
fig. 4 is a schematic structural diagram of an automatic gain control device of a monitoring receiver according to an embodiment of the present application;
fig. 5 is a schematic flow chart of a method for monitoring automatic gain control of a receiver according to an embodiment of the present application;
fig. 6 is a schematic structural diagram of another automatic gain control device for a monitoring receiver according to an embodiment of the present application;
fig. 7 is a schematic diagram of an average amplitude calculation flow provided in an embodiment of the present application.
Detailed Description
In order to make the technical solutions and advantages of the embodiments of the present application more apparent, the following detailed description of exemplary embodiments of the present application is given with reference to the accompanying drawings, and it is apparent that the described embodiments are only some of the embodiments of the present application and not exhaustive of all the embodiments. It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other.
In practicing the present application, the inventors have found that the goal of automatic gain control is to have the total radio frequency signal output amplitude approach and be well below the full scale of the ADC so that the strong and weak signals fall within the spurious free dynamic range of the ADC. The existing automatic gain control method mainly comprises analog feedforward gain control, analog feedback gain control and digital feedback gain control. Whether of the analog feed-forward or analog feedback type, additional rf detection circuitry is required, increasing rf circuitry size and cost. The existing digital feedback type gain control circuit is mainly used for a superheterodyne receiver, performs gain adjustment through digital logarithmic power, performs gain adjustment only on a medium-frequency signal, and is not suitable for an application scene of simultaneous receiving of a plurality of broadband signals.
In view of the foregoing, an embodiment of the present application provides a method and an apparatus for controlling automatic gain of a monitoring receiver, where the apparatus includes: the digital control attenuator, the low noise amplifier, the preselect filter, the variable gain amplifier, the analog-to-digital converter, the digital average amplitude calculation module and the gain adjustment control module; the digital control attenuator is sequentially connected with the low noise amplifier, the preselection filter, the variable gain amplifier and the analog-to-digital converter; the output of the analog-to-digital converter is sequentially connected with a digital average amplitude calculation module and a gain adjustment control module; the output of the gain adjustment control module is respectively connected with the numerical control attenuator and the variable gain amplifier. The device provided by the application realizes automatic control of gain, effectively solves the problems that an analog automatic gain control circuit in the existing receiver is complex, digital feedback type automatic gain control performs gain control by logarithmic digital power, has high calculation complexity, only performs gain adjustment on a medium-frequency signal, and is not suitable for simultaneous receiving of broadband multiple signals.
Referring to fig. 4, an automatic gain control device for a monitoring receiver according to this embodiment includes: a digital controlled attenuator (DATT), a Low Noise Amplifier (LNA), a pre-selection filter, a Variable Gain Amplifier (VGA), an analog-to-digital converter (ADC), a digital average amplitude calculation module (mean_amp_cal), a Gain adjustment control module (gain_adj_ctrl).
The digital control attenuator is sequentially connected with the low noise amplifier, the preselection filter, the variable gain amplifier and the analog-to-digital converter.
The output of the analog-to-digital converter is sequentially connected with a digital average amplitude calculation module and a gain adjustment control module.
The output of the gain adjustment control module is respectively connected with the numerical control attenuator and the variable gain amplifier.
Wherein, the liquid crystal display device comprises a liquid crystal display device,
the numerical control attenuator is a two-gear attenuator, 20dB attenuation and 0dB attenuation are respectively adopted, and the numerical control attenuator defaults to 0dB attenuation.
The fixed gain of the low noise amplifier is 20dB.
The maximum gain adjustment value of the variable gain amplifier is 48dB.
The sampling rate of the analog-to-digital converter is 245.76MHz.
The digital average amplitude calculation module and the gain adjustment control module implement Automatic Gain Control (AGC).
The automatic gain control device of the monitoring receiver provided by the embodiment comprises two stages of gain adjustable devices, wherein the first stage of adjustable gain adopts stepped attenuation, and the second stage of adjustable gain adopts an adjustable gain amplifier.
In the operation process of the automatic gain control device of the monitoring receiver provided by the embodiment, a broadband radio frequency signal firstly passes through a numerical control attenuator, the numerical control attenuator attenuates the radio frequency signal by 0dB or 20dB according to a first gain control instruction sent by an automatic gain control module, then outputs the radio frequency signal to a low noise amplifier, the low noise amplifier fixedly amplifies the signal by 20dB, then outputs the signal to a frequency band preselection filter, outputs the signal to a variable gain amplifier after filtering the signal outside a target frequency band by the preselection filter, and the variable gain amplifier amplifies the signal according to a second gain control instruction sent by the automatic gain control module, and then outputs the signal to an analog-to-digital converter for analog-digital conversion.
The output of the analog-to-digital converter is subjected to automatic gain control, the automatic gain control is realized by an amplitude average value calculation module and a gain adjustment control module, the amplitude average value calculation module obtains an amplitude average value after carrying out a series of processing on the digital signal after analog-to-digital conversion, the amplitude average value is output to the gain adjustment control module, and the gain adjustment module outputs a first gain control instruction and a second gain control instruction which are sequentially connected to a control end of the numerical control attenuator and a control end of the adjustable gain amplifier.
The embodiment provides an automatic gain control device for a monitoring receiver, which comprises: the digital control attenuator, the low noise amplifier, the preselect filter, the variable gain amplifier, the analog-to-digital converter, the digital average amplitude calculation module and the gain adjustment control module; the digital control attenuator is sequentially connected with the low noise amplifier, the preselection filter, the variable gain amplifier and the analog-to-digital converter; the output of the analog-to-digital converter is sequentially connected with a digital average amplitude calculation module and a gain adjustment control module; the output of the gain adjustment control module is respectively connected with the numerical control attenuator and the variable gain amplifier. The device provided by the application realizes automatic control of gain, effectively solves the problems that an analog automatic gain control circuit in the existing receiver is complex, digital feedback type automatic gain control performs gain control by logarithmic digital power, has high calculation complexity, only performs gain adjustment on a medium-frequency signal, and is not suitable for simultaneous receiving of broadband multiple signals.
Based on the automatic gain control device of the monitoring receiver shown in fig. 4, the embodiment provides an automatic gain control method of the monitoring receiver. Referring to fig. 5, the specific implementation procedure is as follows:
501, the digital control attenuator attenuates the input broadband radio frequency signal according to a first gain control instruction of the gain adjustment control module.
The low noise amplifier amplifies 502 the attenuated signal.
503, filtering the amplified signal by a preselection filter to obtain a signal in the target frequency band.
And 504, the variable gain amplifier performs gain adjustment on the signal in the target frequency band according to the second gain control instruction of the gain adjustment control module.
505, the analog-to-digital converter performs analog-to-digital conversion on the gain-adjusted signal.
The digital average amplitude calculation module calculates 506 an average value of the analog-to-digital converted signal.
Specifically, the digital average amplitude calculation module calculates an average value of the analog-to-digital converted signal within each preset time interval (e.g., 1 micro). The digital average amplitude calculation module calculates an average value of a preset number (such as 1024) of output average values.
For example, the absolute value of the analog-to-digital converted signal value is calculated, the absolute values of about 1 microsecond are accumulated and summed, and the average value is calculated to obtain an average value mean1 of the absolute values of about 1 microsecond. The 1024 mean1 are accumulated and summed, and the average value is calculated to obtain an average mean2 of about 1ms, which is the average value of the amplitude of about 1 ms.
507, the gain adjustment control module determines a first gain control instruction and a second gain control instruction according to a relationship between the average value and a preset threshold value.
In this step, three thresholds may be preset, which are respectively a preset high threshold high_th, a preset middle threshold middle_th and a preset low threshold low_th, and are used as thresholds for judging the strong, middle and weak signals.
If the signal amplitude mean2 is higher than or equal to high_th, indicating that the radio frequency signal input to the ADC has approached the full range of the ADC, the gain should be reduced appropriately so as not to risk saturation of the ADC; if the signal amplitude average is lower than or equal to low_th, which means that the signal is weak, the gain should be increased as much as possible, and if the signal amplitude is between low_th and middle_th, the gain should be increased appropriately. In order to accelerate the convergence rate of the AGC to the burst signal, a strategy of fast rising and slow falling is adopted, namely, the step of increasing the gain is larger than the step of reducing the gain.
When mean2 is higher than or equal to high_th, the gain is reduced in steps of a first step size (e.g., 2 dB);
when mean2 is lower than or equal to low_th, setting to maximum gain (e.g., 68 dB);
when mean2 is higher than low_th and lower than middle_th, the gain is increased in steps of a second step (e.g., 6 dB);
when mean2 is higher than or equal to middle_th and lower than high_th, the existing gain is kept unchanged.
After gain adjustment values are obtained, the gain adjustment values are distributed to a two-stage gain adjustment module of the numerical control attenuator and the adjustable gain amplifier.
For example, the specific implementation process is as follows:
1. gain value gain_value is obtained, and the initial value of gain_value is the maximum gain.
2. And adjusting the gain_value according to the relation between the average value and the preset threshold value.
The preset threshold comprises a preset high threshold, a preset middle threshold and a preset low threshold.
If the average value is greater than or equal to the preset high threshold, gain_value=gain_value-first step.
If the average value is less than or equal to the preset low threshold value, gain_value=maximum gain.
If the average value is greater than the preset low threshold and less than the preset medium threshold, gain_value=gain_value+second step.
If the average value is greater than or equal to the preset middle threshold value and less than the preset high threshold value, gain_value=gain_value.
The first step may be 2dB, the maximum gain may be 68dB, and the second step may be 6dB.
The frequency of gain adjustment should not be too fast or too small, and should be determined according to the signal characteristics of the target frequency band, for example, the frequency band of 30 MHz-88 MHz, and there are continuous signals, burst signals, and frequency hopping signals. The duration of the burst signal is typically in the order of several milliseconds to several tens of milliseconds, the guard interval of the frequency hopping signal is typically in the order of 100 microseconds, and the interval time of gain adjustment is typically not less than 500 microseconds in order to reduce the stability of the amplitude of the frequency hopping signal.
Therefore, in the present invention, the frequency of gain adjustment may be set, for example, once every 1ms, since the sampling rate is 245.76MHz, every 2457600 sampling points are 1ms, in order to simplify the calculation of the amplitude average value, the integer power of 2 sampling points closest to 2457600, that is, 256×1024 sampling points are taken as a time window, and the amplitude average value of the time window is calculated.
The process flow of the average amplitude calculation module is shown in fig. 7. The output of the ADC is subjected to absolute value calculation, then the sum1 is obtained by carrying out absolute value accumulation on every 256 points, the sum1 is averaged to obtain the absolute average value mean1 of 256 original sampling points, the accumulation is carried out according to every 1024 mean1, and the average value is calculated to obtain the amplitude average value mean2. Because the points corresponding to the two average value calculations are all the integer powers of 2, a right shift mode can be adopted, and multiplier resources are saved.
Three preset thresholds, namely a preset high threshold high_th, a preset middle threshold middle_th and a preset low threshold low_th, are used as thresholds for signal strength judgment. After the amplitude mean2 is obtained, the mean2 is compared with three thresholds, and the required gain value is determined.
In order to accelerate the convergence rate of the AGC to the burst signal, a strategy of fast rising and slow falling is adopted, namely, the step of increasing the gain is larger than the step of reducing the gain. The specific gain adjustment mode is as follows:
the initial gain value is set to the maximum gain (e.g., 68 dB).
If mean2 is ≡ high_th, the gain is reduced by a first step (e.g., 2 dB), i.e., gain_value=gain_value-2.
If mean2 is equal to or less than low_th, the gain is set to the maximum gain, that is, gain_value=68.
If mean2 > low_th and mean2 < middle_th, the gain is increased by a second step (e.g., 6 dB), i.e., gain_value=gain_value+6.
If mean2. Gtoreq.middle_th and mean2 < high_th, then gain_value remains unchanged.
3. And determining a first gain control instruction and a second gain control instruction according to the current gain_value.
The numerical control attenuator is a two-gear attenuator, namely 20dB attenuation and 0dB attenuation.
Therefore, the implementation process of determining the first gain control instruction and the second gain control instruction according to the current gain_value is as follows:
if the current gain_value is larger than the maximum gain, setting the gain_value as the maximum gain, and determining that the first gain control instruction is attenuated by 0dB and the second gain control instruction is a gain maximum adjustment value of the gain adjustment variable gain amplifier.
If the current gain value is not greater than the maximum gain but greater than or equal to the gain maximum adjustment value of the variable gain amplifier, then the first gain control command is determined to be attenuation 0dB and the second gain control command is determined to be gain adjustment gain value- (maximum gain-gain maximum adjustment value of the variable gain amplifier).
If the current gain value is smaller than the gain maximum adjustment value of the variable gain amplifier, the first gain control instruction is determined to be attenuated by 20dB and the second gain control instruction is determined to be gain adjustment gain value.
For example, if gain_value > 68 is the maximum gain (e.g., 68 dB) based on gain_value obtained in 2, gain_value is set to the maximum gain (e.g., 68 dB), and then gain control command 1 and gain control command 2 are determined based on the magnitude of the values thereof, i.e., the first gain control command is determined to attenuate by 0dB and the second gain control command is determined to be the gain maximum adjustment value (i.e., 48 dB) of the gain-adjusted variable gain amplifier. If the current gain value is less than or equal to the maximum gain (e.g. 68 dB), but the current gain value is greater than or equal to the maximum gain adjustment value (i.e. 48 dB) of the variable gain amplifier, the first gain control instruction is attenuated by 0dB, and the gain of the second gain control instruction is gain value- (68 dB-48 dB). If the current gain value < is less than the gain maximum adjustment value (i.e., 48 dB) of the variable gain amplifier, the first gain control command is attenuation by 20dB and the second gain control command is gain value.
The first gain control command obtained in this step is transmitted to the digitally controlled attenuator to cause the digitally controlled attenuator to perform step 501, and the second gain control command is transmitted to the variable gain amplifier to cause the variable gain amplifier to perform step 504.
The automatic gain control device of the monitoring receiver applying the method provided by the implementation is shown in fig. 5.
In the method for controlling the automatic gain of the monitoring receiver provided by the embodiment, the broadband radio frequency signal firstly passes through the numerical control attenuator, the numerical control attenuator attenuates the radio frequency signal by 0dB or 20dB according to the first gain control instruction sent by the automatic gain control module, then outputs the radio frequency signal to the low noise amplifier, the low noise amplifier fixedly amplifies the signal by 20dB, then outputs the signal to the frequency band preselection filter, outputs the signal to the variable gain amplifier after filtering the signal outside the target frequency band by the preselection filter, and the variable gain amplifier amplifies the signal according to the second gain control instruction sent by the automatic gain control module, and then outputs the signal to the analog-to-digital converter for analog-to-digital conversion.
The output of the analog-to-digital converter is subjected to automatic gain control, the automatic gain control is realized by an amplitude average value calculation module and a gain adjustment control module, the amplitude average value calculation module obtains an amplitude average value after carrying out a series of processing on the digital signal after analog-to-digital conversion, the amplitude average value is output to the gain adjustment control module, and the gain adjustment module outputs a first gain control instruction and a second gain control instruction which are sequentially connected to a control end of the numerical control attenuator and a control end of the adjustable gain amplifier.
According to the automatic gain control method for the monitoring receiver, the gain of the radio frequency link is adjusted through the magnitude of the digital average amplitude, so that the output amplitude of the radio frequency signal is as close as possible and is properly smaller than the full range of the analog-to-digital converter.
In addition, the automatic gain control method of the monitoring receiver does not convert the average amplitude into the logarithmic power, and the magnitude of the digital average amplitude is directly compared with three thresholds to make a gain adjustment decision.
According to the automatic gain control method for the monitoring receiver, automatic Gain Control (AGC) is achieved through the digital average amplitude calculation module and the gain adjustment control module.
According to the automatic gain control method for the monitoring receiver, the gain is controlled based on the average amplitude, and when the average amplitude is calculated, the multiplier resource is omitted in a right shifting mode.
The automatic gain control method of the monitoring receiver provided by the embodiment is different from most gain control methods, and is directly used for carrying out gain adjustment based on the average amplitude, so that the average amplitude is not converted into logarithm, the time delay is reduced, and meanwhile, the calculation resources are saved.
The gain adjustment strategy of the automatic gain control method of the monitoring receiver provided by the embodiment adopts a fast-rising and slow-falling mode, and has stronger adaptability to short-time burst signals and frequency hopping signals.
The automatic gain control method of the monitoring receiver solves the problem of gain control stability under the condition that strong and weak signals exist simultaneously during broadband reception by setting three thresholds.
The embodiment provides a method for controlling automatic gain of a monitoring receiver, and a device applying the method comprises the following steps: the digital control attenuator, the low noise amplifier, the preselect filter, the variable gain amplifier, the analog-to-digital converter, the digital average amplitude calculation module and the gain adjustment control module; the digital control attenuator is sequentially connected with the low noise amplifier, the preselection filter, the variable gain amplifier and the analog-to-digital converter; the output of the analog-to-digital converter is sequentially connected with a digital average amplitude calculation module and a gain adjustment control module; the output of the gain adjustment control module is respectively connected with the numerical control attenuator and the variable gain amplifier. According to the method, an input broadband radio frequency signal is attenuated through a numerical control attenuator according to a first gain control instruction of a gain adjustment control module; amplifying the attenuated signal by a low noise amplifier; filtering the amplified signal through a pre-selection filter to obtain a signal in a target frequency band; gain adjustment is carried out on signals in the target frequency band through the variable gain amplifier according to a second gain control instruction of the gain adjustment control module; performing analog-to-digital conversion on the signal subjected to gain adjustment through an analog-to-digital converter; calculating the average value of the analog-to-digital converted signal by a digital average amplitude calculation module; and determining a first gain control instruction and a second gain control instruction according to the relation between the average value and a preset threshold value by a gain adjustment control module. The method realizes the automatic control of the gain, effectively solves the problems that the analog automatic gain control circuit in the existing receiver is complex, the digital feedback automatic gain control performs gain control by logarithmic digital power, the calculation complexity is high, only performs gain adjustment on the intermediate frequency signal, and is not suitable for simultaneous receiving of broadband multiple signals.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein. The solutions in the embodiments of the present application may be implemented in various computer languages, for example, object-oriented programming language Java, and an transliterated scripting language JavaScript, etc.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the application.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the spirit or scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims and the equivalents thereof, the present application is intended to cover such modifications and variations.
Claims (10)
1. An apparatus for monitoring automatic gain control of a receiver, the apparatus comprising:
the digital control attenuator, the low noise amplifier, the preselect filter, the variable gain amplifier, the analog-to-digital converter, the digital average amplitude calculation module and the gain adjustment control module;
the digital control attenuator is sequentially connected with the low noise amplifier, the pre-selection filter, the variable gain amplifier and the analog-to-digital converter;
the output of the analog-to-digital converter is sequentially connected with the digital average amplitude calculation module and the gain adjustment control module;
and the output of the gain adjustment control module is respectively connected with the numerical control attenuator and the variable gain amplifier.
2. The apparatus of claim 1, wherein the digitally controlled attenuator is a two-stage attenuator, 20dB attenuation and 0dB attenuation, respectively, and the digitally controlled attenuator defaults to 0dB attenuation.
3. The apparatus of claim 1, wherein the low noise amplifier has a fixed gain of 20dB.
4. The apparatus of claim 1, wherein the variable gain amplifier has a gain maximum adjustment value of 48dB.
5. The apparatus of claim 1, wherein the analog-to-digital converter has a sampling rate of 245.76MHz.
6. A method of monitoring automatic gain control of a receiver, the method being applied to the apparatus of any one of claims 1 to 5, the method comprising:
the digital control attenuator attenuates the input broadband radio frequency signal according to a first gain control instruction of the gain adjustment control module;
amplifying the attenuated signal by a low noise amplifier;
the preselection filter filters the amplified signals to obtain signals in a target frequency band;
the variable gain amplifier carries out gain adjustment on the signals in the target frequency band according to a second gain control instruction of the gain adjustment control module;
the analog-to-digital converter performs analog-to-digital conversion on the signal after gain adjustment;
the digital average amplitude calculation module calculates the average value of the analog-to-digital converted signal;
the gain adjustment control module determines a first gain control instruction and a second gain control instruction according to the relation between the average value and a preset threshold value.
7. The method of claim 6, wherein the digital average amplitude calculation module calculates an average of the analog-to-digital converted signal, comprising:
the digital average amplitude calculation module calculates the average value of the analog-to-digital converted signal in each preset time interval;
the digital average amplitude calculation module calculates an average value of a preset number of output average values.
8. The method of claim 6, wherein the gain adjustment control module determining the first gain control command and the second gain control command based on a relationship between the average value and a preset threshold value, comprising:
gain value gain_value is obtained, and the initial value of the gain_value is the maximum gain;
adjusting the gain_value according to the relation between the average value and a preset threshold value;
and determining a first gain control instruction and a second gain control instruction according to the current gain_value.
9. The method of claim 8, wherein the preset threshold comprises a preset high threshold, a preset medium threshold, and a preset low threshold;
the adjusting the gain_value according to the relation between the average value and the preset threshold value comprises the following steps:
if the average value is greater than or equal to a preset high threshold value, gain_value=gain_value-first step length;
if the average value is less than or equal to a preset low threshold value, gain_value=maximum gain;
if the average value is greater than a preset low threshold value and less than a preset medium threshold value, gain_value=gain_value+a second step length;
if the average value is greater than or equal to a preset middle threshold value and less than a preset high threshold value, gain_value=gain_value.
10. The method of claim 8, wherein the digitally controlled attenuator is a two-stage attenuator, 20dB attenuation and 0dB attenuation, respectively;
the determining the first gain control instruction and the second gain control instruction according to the current gain_value comprises the following steps:
if the current gain_value is larger than the maximum gain, setting the gain_value as the maximum gain, and determining that the first gain control instruction is attenuation 0dB and the second gain control instruction is gain adjustment of the gain maximum adjustment value of the variable gain amplifier;
if the current gain_value is not greater than the maximum gain but greater than or equal to the gain maximum adjustment value of the variable gain amplifier, determining that the first gain control instruction is attenuated by 0dB and the second gain control instruction is gain adjustment gain_value- (maximum gain-gain maximum adjustment value of the variable gain amplifier);
if the current gain_value is smaller than the gain maximum adjustment value of the variable gain amplifier, determining that the first gain control instruction is attenuated by 20dB and the second gain control instruction is gain adjustment gain_value.
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| CN202310424725.2A CN116471656A (en) | 2023-04-19 | 2023-04-19 | Automatic gain control method and device for monitoring receiver |
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| CN202310424725.2A CN116471656A (en) | 2023-04-19 | 2023-04-19 | Automatic gain control method and device for monitoring receiver |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116719770A (en) * | 2023-08-08 | 2023-09-08 | 北京国科天迅科技股份有限公司 | Self-adaptive high-speed serial data transmission device |
| CN116908886A (en) * | 2023-09-13 | 2023-10-20 | 北京凯芯微科技有限公司 | System and method for automatically detecting gain range of GNSS module |
| CN117236455A (en) * | 2023-11-15 | 2023-12-15 | 苏州元脑智能科技有限公司 | Signal detection method and device, storage medium and electronic device |
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- 2023-04-19 CN CN202310424725.2A patent/CN116471656A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116719770A (en) * | 2023-08-08 | 2023-09-08 | 北京国科天迅科技股份有限公司 | Self-adaptive high-speed serial data transmission device |
| CN116719770B (en) * | 2023-08-08 | 2024-01-09 | 北京国科天迅科技股份有限公司 | Self-adaptive high-speed serial data transmission device |
| CN116908886A (en) * | 2023-09-13 | 2023-10-20 | 北京凯芯微科技有限公司 | System and method for automatically detecting gain range of GNSS module |
| CN116908886B (en) * | 2023-09-13 | 2023-12-26 | 北京凯芯微科技有限公司 | System and method for automatically detecting gain range of GNSS module |
| CN117236455A (en) * | 2023-11-15 | 2023-12-15 | 苏州元脑智能科技有限公司 | Signal detection method and device, storage medium and electronic device |
| CN117236455B (en) * | 2023-11-15 | 2024-02-09 | 苏州元脑智能科技有限公司 | Signal detection method and device, storage medium and electronic device |
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