Device and application method for identifying pulse amplitude modulation signals based on level control

Abstract

The present invention discloses a device and an application method for identifying a pulse amplitude modulation signal based on level control, including: a radio frequency front end for filtering and amplifying the received signal; a down-conversion component for performing frequency conversion processing on the signal processed by the radio frequency front end; an intermediate frequency conditioning component for performing secondary frequency conversion processing on the signal processed by the down-conversion component; a level control component for conditioning the signal amplitude in the radio frequency front end and the intermediate frequency conditioning component; a detection component arranged at the output end of the intermediate frequency conditioning component for adjusting the voltage magnitude of the level control component based on its output signal and a reference voltage. The present invention provides a device and an application method for identifying a pulse amplitude modulation signal based on level control, which realizes the reception and demodulation of the pulse amplitude modulation signal with the simplest circuit components, has high reception sensitivity, can accurately identify and receive signals with different amplitude sizes, and can simultaneously perform high-fidelity restoration of useful information during the reception process.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication. More specifically, the present invention relates to a device and an application method for identifying a pulse amplitude modulation signal based on level control in the case of an amplitude modulation radio receiver. Background Art

[0002] A radio receiver, abbreviated as a receiver, is an important part of the wireless communication field. It is an electronic device that can select, transform, and amplify the radio signals received by the antenna to obtain the required information. Its components include high-frequency, intermediate-frequency, and low-frequency amplifiers, frequency converters, and demodulators. According to the modulation method of the received signal, it can be divided into amplitude modulation receivers, frequency modulation receivers, and pulse modulation receivers, etc.

[0003] However, the existing amplitude modulation receivers have the disadvantage that the signals received by the external antenna are messy. In the case of different signal amplitude sizes, their reception sensitivity is low, and the useful information in the received signals cannot be restored with high fidelity. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and / or defects and provide at least the advantages described hereinafter.

[0005] To achieve these objects and other advantages according to the present invention, there is provided a device for identifying a pulse amplitude modulation signal based on level control, including:

[0006] A radio frequency front end for filtering and amplifying the received signal;

[0007] A down-conversion component for performing frequency conversion processing on the signal processed by the radio frequency front end;

[0008] An intermediate-frequency conditioning component for performing secondary frequency conversion processing on the signal processed by the down-conversion component;

[0009] A level control component for conditioning the signal amplitude in the radio frequency front end and the intermediate-frequency conditioning component;

[0010] A detection component provided at the output end of the intermediate-frequency conditioning component for adjusting the voltage magnitude of the level control component based on its output signal and a reference voltage.

[0011] Preferably, the radio frequency front end is configured to include:

[0012] A band-pass filter for performing anti-aliasing filtering processing on the radio frequency signal input at the external antenna;

[0013] A first amplifier provided at the output end of the band-pass filter for amplifying the low noise in its output signal.

[0014] Preferably, the down-conversion component is configured to include:

[0015] A mixer cooperating with the output end of the radio frequency front end;

[0016] A local oscillator source cooperating with the mixer to down-convert the signal flowing through the mixer to an intermediate frequency signal.

[0017] Preferably, the intermediate frequency conditioning component is configured to include:

[0018] A narrowband filter cooperating with the output end of the down-conversion component;

[0019] A second amplifier disposed at the output end of the narrowband filter to amplify the intermediate frequency signal output therefrom.

[0020] Preferably, the level control component is configured to include:

[0021] A first voltage-controlled attenuator disposed in the radio frequency front end;

[0022] At least one second voltage-controlled attenuator disposed in the intermediate frequency conditioning component;

[0023] Wherein, the first voltage-controlled attenuator and the second voltage-controlled attenuator are both configured to be communicatively connected to the detection component.

[0024] Preferably, the detection component is configured to include:

[0025] A detector cooperating with the output end of the intermediate frequency conditioning component;

[0026] A comparison amplifier cooperating with the detector to output a corresponding control voltage to the level control component based on a reference voltage and a detection result;

[0027] Wherein, the output end of the comparison amplifier is communicatively connected to the level control component;

[0028] The output end of the detector is further communicatively connected to a signal processing module, and the signal processing module is communicatively connected to the comparison amplifier through an A / D sampling module.

[0029] A method for applying a device for identifying a pulse amplitude modulation signal based on level control. In a pulse amplitude modulation microwave receiving system, after filtering, low-noise amplifying, receiving down-converting, and narrowband filtering the received signal, an effective detection mean value is obtained through detection and demodulation, and then, based on the difference comparison result between the mean value and a reference voltage, the magnitude of the control voltage of the level control component is adjusted, thereby identifying signals of different amplitude magnitudes.

[0030] Preferably, its working process is configured to include:

[0031] S1. The external antenna receives signals and transmits them to the RF front-end;

[0032] S2. The band-pass filter in the RF front-end filters out out-of-band interference signals and image frequencies in the received RF signals;

[0033] S3. The first amplifier in the RF front-end performs low-noise amplification on the signals received from the band-pass filter;

[0034] S4. The down-conversion component down-converts the high-frequency signals received from the first amplifier to intermediate-frequency signals through a mixer and a local oscillator;

[0035] S5. The narrow-band filter in the intermediate-frequency conditioning component reduces the receive bandwidth to filter out mixer spurs in the output signals of the mixer;

[0036] S6. Through the second amplifier in the intermediate-frequency conditioning component, the signals with reduced receive bandwidth are amplified to bring their signals within the dynamic range of the RF detector;

[0037] S7. The RF detector receives the output signals of the second amplifier to obtain the corresponding mean value and outputs it to the comparison amplifier;

[0038] S8. Based on the mean value received by the comparison amplifier and the reference voltage, a closed negative feedback loop is formed in combination with the level control component. Through the difference operation of the comparison amplifier, the corresponding calculation structure is obtained. Based on the calculation results, the magnitude of the control voltage in the level control component is adjusted within the dynamic range, so as to stabilize the signal output to a fixed output, thereby improving the pulse characteristic index of the peak detection result.

[0039] Preferably, it further includes:

[0040] S9. The signal processing module reads and demodulates the peak detection result output by the detector, and at the same time performs A / D sampling on the current control voltage of the level control component through the A / D sampling module to obtain information corresponding to the current signal amplitude.

[0041] Preferably, in S9, it further includes:

[0042] When the signal processing module operates in the multi-channel receive mode, it receives the A / D samples of each channel to judge the communication status of each channel based on this, and switches the working status of each channel through the control switch set at the antenna end.

[0043] The present invention has at least the following beneficial effects: First, the present invention provides a recognition (reception) device dedicated to the amplitude modulation signal mode, which realizes the reception and demodulation of pulse amplitude modulation signals with the simplest circuit components, has high reception sensitivity, can accurately recognize and receive signals of different amplitude sizes, and can highly faithfully restore useful information during the reception process.

[0044] Second, the present invention provides an application method, which is applicable to the reception and demodulation of pulse amplitude modulation signals. By filtering, low-noise amplifying, automatically controlling the level, receiving down-converting, and narrow-band filtering the received signals, useful information is demodulated through detection. The control voltage in the automatic level control circuit can accurately reflect the amplitude size of the received signal. The circuit design of this method is simple, has high reception sensitivity, can accurately recognize and highly faithfully restore useful information.

[0045] Third, when the method of the present invention is applied in a multi-channel reception system, it can simultaneously detect signals of multiple channels and selectively close low-quality reception channels differentially, thereby ensuring a more excellent reception effect.

[0046] Other advantages, objectives, and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a principle block diagram of a device for recognizing pulse amplitude modulation signals based on level control in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] The following further describes the present invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0049] It should be understood that terms such as "having", "comprising", and "including" used herein do not preclude the presence or addition of one or more other elements or their combinations.

[0050] It should be noted that in the description of the present invention, the orientation or positional relationship indicated by the terms is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0051] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, terms such as "installation", "provided with", "sheathed / connected", "connection", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, an electrical connection, it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0052] An implementation form of a device for identifying a pulse amplitude modulation signal based on level control according to the present invention includes:

[0053] A radio frequency front end for filtering and amplifying the received signal, which is used to perform anti-aliasing bandpass filtering and low-noise amplification on the received signal, has good suppression of out-of-band interference and image frequency, and improves the receiving anti-interference performance;

[0054] A down-conversion component for performing frequency conversion processing on the signal processed by the radio frequency front end, which is used to down-convert the received radio frequency signal and the local oscillator source to an intermediate frequency signal through a mixer;

[0055] An intermediate frequency conditioning component for performing secondary frequency conversion processing on the signal processed by the down-conversion component, which is used to amplify the intermediate frequency signal and perform narrowband filtering, provide receiving gain, reduce the receiving bandwidth, and provide receiving sensitivity;

[0056] A level control component for conditioning the signal amplitude in the radio frequency front end and the intermediate frequency conditioning component, which is used to form a negative feedback circuit to achieve a stable output intermediate frequency amplitude under different input signal level sizes, thereby realizing the detection of high-quality pulse signals;

[0057] A detection component provided at the output end of the intermediate frequency conditioning component to adjust the voltage magnitude of the level control component based on its output signal and a reference voltage, which is used to perform mean and peak detection on the signal conditioned by the intermediate frequency, and the mean detection result is differentially amplified with the reference voltage to provide an accurate control voltage for automatic level control, thereby ensuring the stability of the peak detection result output.

[0058] Such as Figure 1 , in another example, the radio frequency front end is configured to include:

[0059] A bandpass filter 1 for performing anti-aliasing filtering on the radio frequency signal input at the external antenna, the function of the bandpass filter;

[0060] A first amplifier 2 is provided at the output end of the band-pass filter to amplify the low noise in its output signal. It is used to amplify the low noise in the filtered signal. Then, through the cooperation of the band-pass filter and the first amplifier, out-of-band interference and image frequency are well suppressed, and the anti-interference performance of the receiver is improved.

[0061] For example Figure 1 in another example, the down-conversion component is configured to include:

[0062] A mixer 3 that cooperates with the output end of the RF front-end. It is configured as a subtraction mixer and is set behind the low-noise amplifier to directly process the amplified RF signal to obtain the corresponding intermediate-frequency signal.

[0063] A local oscillator source 4 that cooperates with the mixer to down-convert the signal flowing through the mixer to an intermediate-frequency signal. It is used to down-convert the received signal from a high frequency to an intermediate frequency through the cooperation of the local oscillator source and the subtraction mixer.

[0064] For example Figure 1 in another example, the intermediate-frequency conditioning component is configured to include:

[0065] A narrow-band filter 5 that cooperates with the output end of the down-conversion component, also known as a narrow-band band-pass filter, which is used to obtain a very narrow passband and a relatively steep transition band. Its function is to separate the useful signal from the noise, improve the anti-interference performance and signal-to-noise ratio of the signal; filter out the frequency components that are not of interest and improve the analysis accuracy; separate a single frequency component from complex frequency components.

[0066] A second amplifier 6 is provided at the output end of the narrow-band filter to amplify the output intermediate-frequency signal. It is used to improve the reception gain of the intermediate-frequency signal. Its combination with the second amplifier is used to amplify the signal and perform narrow-band filtering on the intermediate-frequency signal, provide reception gain, reduce the reception bandwidth, and provide reception sensitivity.

[0067] For example Figure 1 in another example, the level control component is configured to include:

[0068] A first voltage-controlled attenuator 7 provided in the RF front-end;

[0069] A second voltage-controlled attenuator A 8 and a second voltage-controlled attenuator B 9 provided in the intermediate-frequency conditioning component. In actual operation, the second voltage-controlled attenuator A and the second voltage-controlled attenuator B are respectively provided at the front end and the rear end of the second amplifier to adjust the attenuation magnitude of the voltage-controlled attenuator by controlling the voltage, thereby ensuring the stability of the output signal.

[0070] Among them, the first voltage-controlled attenuator and the second voltage-controlled attenuator are both configured to be communicatively connected to the detection component, and are operative to receive the control voltage output by the detection component and adjust the attenuation magnitude of each voltage-controlled attenuator based on the control voltage.

[0071] For example Figure 1 , in another example, the detection component is configured to include:

[0072] A detector 10 that cooperates with the output end of the intermediate-frequency conditioning component, which is operative to perform mean and peak detection on the intermediate-frequency conditioned signal respectively. The mean detection result is differentially amplified with the reference voltage to provide an accurate control voltage for automatic level control, and the peak detection result is output to the signal processing module;

[0073] A comparison amplifier 11 that cooperates with the detector to output a corresponding control voltage to the level control component based on the reference voltage and the detection result, which is used to calculate the difference between the mean detection result and the reference voltage to determine whether the control voltage needs to be adjusted according to the calculation result;

[0074] Among them, the output end of the comparison amplifier is communicatively connected to the level control component;

[0075] The output end of the detector is also communicatively connected to a signal processing module 12. The signal processing module and the comparison amplifier are communicatively connected through an A / D sampling module 13. The signal processing module reads the peak detection result and demodulates the useful information, and at the same time performs A / D sampling on the control voltage required for automatic level control to obtain the received signal amplitude magnitude information.

[0076] A method for applying a device based on level control to identify pulse amplitude modulation signals. In a pulse amplitude modulation microwave receiving system, after filtering, low-noise amplification, receiving down-conversion, and narrow-band filtering of the received signal, an effective detection mean is obtained through detection and demodulation. Then, based on the difference comparison result between the mean and the reference voltage, the control voltage magnitude of the level control component is adjusted, and then signals of different amplitude magnitudes are identified. In this solution, after filtering, amplifying, frequency-converting, and detecting the signal, according to the magnitude of the signal in the receiving channel, the attenuation magnitude of the signal on the output path is adjusted to ensure the stability of the output signal, and at the same time, signals of different amplitude magnitudes can be accurately identified to ensure its receiving sensitivity.

[0077] In another example, its working process is configured to include:

[0078] S1. The external antenna receives the signal and transmits it to the RF front end;

[0079] S2. The band - pass filter in the RF front - end filters out out - of - band interference signals and image frequencies in the received RF signals;

[0080] S3. The first amplifier in the RF front - end performs low - noise amplification on the signals received from the band - pass filter;

[0081] S4. The down - conversion component down - converts the high - frequency signals received from the first amplifier to intermediate - frequency signals through a mixer and a local oscillator;

[0082] S5. The narrow - band filter in the intermediate - frequency conditioning component reduces the receiving bandwidth to filter out mixer spurs in the output signals of the mixer;

[0083] S6. Through the second amplifier in the intermediate - frequency conditioning component, the signals with reduced receiving bandwidth are amplified to bring their signals within the dynamic range of the RF detector;

[0084] S7. The RF detector receives the output signals of the second amplifier to obtain the corresponding mean value and outputs it to the comparison amplifier;

[0085] S8. Based on the mean value received by the comparison amplifier and the reference voltage, combined with the level control component to form a closed negative - feedback loop, the corresponding calculation result is obtained through the difference operation of the comparison amplifier, so as to adjust the magnitude of the control voltage in the level control component within the dynamic range based on the calculation result, so as to stabilize the signal output to a fixed output, thereby improving the pulse characteristic index of the peak detection result. In this solution, the level control component is implemented based on a voltage - controlled attenuator. The voltage - controlled attenuator is distributed in the RF front - end and the intermediate - frequency conditioning circuit. Combining the effective - value detection result (mean value) of the last stage and the reference voltage to form a closed negative - feedback loop, the signal within the dynamic range can be stabilized to a certain fixed level (determined by the reference voltage) for output, improving the pulse characteristic index of the peak detection result.

[0086] In another example, it further includes:

[0087] S9. The signal processing module reads and demodulates the peak detection result output by the detector, and at the same time performs A / D sampling on the current control voltage of the level control component through the A / D sampling module to obtain information corresponding to the current signal amplitude. In this solution, the signal processing module can be implemented by processing chips such as FPGA, ARM, and single - chip microcomputer, which is used to read the peak detection result and demodulate useful information, and at the same time perform A / D sampling on the control voltage required for automatic level control and obtain the received signal amplitude information.

[0088] In another example, in S9, it further includes:

[0089] When the signal processing module operates in the multi-channel receiving mode, it receives the A / D samples of each channel to judge the communication status of each channel based on this, and switches the working status of each channel through the control switch set at the antenna end. In this solution, it can be applied to a multi-channel receiving system to simultaneously detect multi-channel signals and selectively close low-quality receiving channels, thereby ensuring a more excellent receiving effect.

[0090] Embodiment:

[0091] When the RF input is 0, the detector detects no result. Then, when the comparison amplifier performs the difference operation, its calculation result is the reference voltage value. Here, the difference is high, and no operation is performed on the control voltage of the level attenuator.

[0092] When the RF input is not 0, the detector detects the corresponding result, and when the calculation result of the comparison amplifier during the difference operation is 0, the difference here is low, and the control voltage of the level attenuator is set to a higher value within the dynamic range. In this case, the magnitude of the control voltage comes from the result of the difference operation of the comparison amplifier. When the control voltage is small, it proves that the input signal is large, and the attenuation value of the level attenuator is required to control and adjust the signal output to ensure the stability of the received signal, and vice versa.

[0093] The above solution is only an illustration of a preferred example, but is not limited thereto. When implementing the present invention, appropriate substitutions and / or modifications can be made according to the needs of the user.

[0094] The number of devices and the processing scale described here are used to simplify the description of the present invention. The application, modification, and variation of the present invention are obvious to those skilled in the art.

[0095] Although the embodiments of the present invention have been disclosed as above, it is not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A device for identifying pulse amplitude modulation signals based on level control, characterized in that, it includes: a radio frequency front end for filtering and amplifying the received signal; a down-conversion component for performing frequency conversion processing on the signal processed by the radio frequency front end; an intermediate frequency conditioning component for performing secondary frequency conversion processing on the signal processed by the down-conversion component; a level control component for conditioning the signal amplitude in the radio frequency front end and the intermediate frequency conditioning component; a detection component arranged at the output end of the intermediate frequency conditioning component to adjust the voltage magnitude of the level control component based on its output signal and a reference voltage; It also includes a method for the application device: in a pulse amplitude modulation microwave receiving system, after filtering, low-noise amplifying, receiving down-converting, and narrow-band filtering the received signal, an effective detection mean value is obtained through detection and demodulation, and then based on the comparison result of the difference between the mean value and the reference voltage, the control voltage magnitude of the level control component is adjusted, thereby identifying signals of different amplitude magnitudes; The radio frequency front end is configured to include: a band-pass filter for performing anti-aliasing filtering on the radio frequency signal input at the external antenna; a first amplifier arranged at the output end of the band-pass filter to amplify the low noise in its output signal; The down-conversion component is configured to include: a mixer cooperating with the output end of the radio frequency front end; a local oscillator source cooperating with the mixer to down-convert the signal flowing through the mixer to an intermediate frequency signal; The intermediate frequency conditioning component is configured to include: a narrow-band filter cooperating with the output end of the down-conversion component; a second amplifier arranged at the output end of the narrow-band filter to amplify the intermediate frequency signal output therefrom; The level control component is configured to include: a first voltage-controlled attenuator arranged in the radio frequency front end; at least one second voltage-controlled attenuator arranged in the intermediate frequency conditioning component; wherein, the first voltage-controlled attenuator and the second voltage-controlled attenuator are both configured to be communicatively connected to the detection component; The detection component is configured to include: a detector cooperating with the output end of the intermediate frequency conditioning component; a comparison amplifier cooperating with the detector to output a corresponding control voltage to the level control component based on the reference voltage and the detection result; wherein, the output end of the comparison amplifier is communicatively connected to the level control component; The output end of the detector is also communicatively connected to a signal processing module, and the signal processing module is communicatively connected to the comparison amplifier through an A / D sampling module; The working process is configured to include: S1. The external antenna receives the signal and transmits it to the radio frequency front end; S2. The band-pass filter in the radio frequency front end filters out out-of-band interference signals and image frequencies in the received radio frequency signal; S3. The first amplifier in the radio frequency front end performs low-noise amplification on the signal received from the band-pass filter; S4. The down-conversion component down-converts the high-frequency signal received from the first amplifier to an intermediate frequency signal through the mixer and the local oscillator source; S5. The narrow-band filter in the intermediate frequency conditioning component reduces the reception bandwidth to filter out mixing spurs in the output signal of the mixer; S6. Through the second amplifier in the intermediate frequency conditioning component, the signal after reducing the receiving bandwidth is amplified so that its signal is amplified within the dynamic range of the radio frequency detector; S7. The radio frequency detector receives the output signal of the second amplifier to obtain the corresponding mean value and output it to the comparison amplifier; S8. Based on the mean value received by the comparison amplifier and the reference voltage, a closed negative feedback loop is formed in combination with the flattening control component. Through the difference operation of the comparison amplifier, the corresponding calculation structure is obtained, and based on the calculation result, the magnitude of the control voltage in the level control component is adjusted within the dynamic range, so as to stabilize the signal output to a fixed output, thereby improving the pulse characteristic index of the peak detection result; It further includes: S9. The signal processing module reads and demodulates the peak detection result output by the detector, and at the same time performs A / D sampling on the current control voltage of the level control component through the A / D sampling module to obtain information corresponding to the current signal amplitude; In S9, it further includes: When the signal processing module operates in the multi-channel receiving mode, it receives the A / D sampling of each channel, judges the communication status of each channel based on this, and switches the working status of each channel through the control switch set at the antenna end.

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