A device and method for automatic control of sensitivity of a signal detection channel

Abstract

The application discloses a device and method for automatically controlling sensitivity of a signal detection channel, comprising a control module, a processing module and a multi-channel receiving channel module; an input end of the multi-channel receiving channel module is connected with a signal receiving antenna module, and an output end of the multi-channel receiving channel module is connected with an input end of the processing module; an output end of the processing module is connected with an input end of the control module; the multi-channel receiving channel module comprises a plurality of channel channels; the processing module judges the complexity of an electromagnetic environment around the signal receiving antenna module based on signals output by the multi-channel receiving channel module, and outputs a judgment result to the control module; and the control module controls corresponding channel channels in the plurality of channel channels to connect the signal receiving antenna module with the processing module according to the signals output by the processing module. The sensitivity of the signal detection channel can be automatically switched according to the electromagnetic environment where the device is located, and better detection effects can be achieved in different electromagnetic environments.

Description

Technical Field

[0001] This invention relates to the field of signal detection technology, and in particular to a device and method for automatic control of the sensitivity of a signal detection channel. Background Technology

[0002] In scenarios where radio spectrum detection technology is used to detect unauthorized drones, there are frequent transitions between complex electromagnetic environments in cities and ideal electromagnetic environments. This results in a challenge in maintaining good detection performance across different environments while ensuring high sensitivity of the detection channel. Specifically, in complex electromagnetic environments, for consumer drones, the detected signal is difficult to distinguish from co-frequency power and civilian communication signals, requiring a sacrifice in receiver channel sensitivity to suppress co-frequency or near-frequency interference. In relatively ideal electromagnetic environments, to increase detection range, the receiver channel sensitivity needs to be as high as possible. Existing technologies suffer from drawbacks such as the inability to adaptively change receiver channel sensitivity and the inability to simultaneously address the detection performance of drone target signals in different electromagnetic environments. Furthermore, engineering implementations cannot simultaneously meet all these requirements. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the present invention provides a device and method for automatic control of the sensitivity of the signal detection channel. The device automatically switches the sensitivity of the signal detection channel based on its real-time monitoring of the current electromagnetic environment. The implementation method is flexible and reliable, and it can achieve good detection results in different electromagnetic environments.

[0004] Technical Solution: To achieve the above objectives, the present invention provides an apparatus and method for automatic control of the sensitivity of a signal detection channel, comprising a control module, a processing module, and a multi-channel receiving channel module; the input end of the multi-channel receiving channel is connected to a signal receiving antenna module, and the output end of the multi-channel receiving channel module is connected to the input end of the processing module; the output end of the processing module is connected to the input end of the control module, and the multi-channel receiving channel module includes several channel channels; the processing module determines the complexity of the electromagnetic environment surrounding the signal receiving antenna module based on the signal output by the multi-channel receiving channel module, and outputs the determination result to the control module; the control module controls the corresponding channel among the several channel channels to connect the signal receiving antenna module and the processing module according to the signal output by the processing module.

[0005] Furthermore, the input terminals of the plurality of channel channels are connected to the signal receiving antenna module through the first channel switch module, and the output terminals of the plurality of channel channels are connected to the input terminals of the processing module through the second channel switch module.

[0006] Furthermore, both the first channel switch module and the second channel switch module are provided with a first switch channel and a second switch channel corresponding to any one of the plurality of channel channels; the control module controls the first switch channel and the second switch channel corresponding to any one of the plurality of channel channels to open, so that any one channel channel connects the signal receiving antenna module and the processing module.

[0007] The first channel switch module and the second channel switch module are each provided with a first channel sub-switch and a second channel sub-switch corresponding to any one of the plurality of channel channels; the control module controls the first channel sub-switch and the second channel sub-switch corresponding to any one of the plurality of channel channels to open, so that any one channel connects the signal receiving antenna module and the processing module.

[0008] Furthermore, the bandwidth (BW) of the signal detected by the drone itself... T The operating bandwidth range (BW) of the detected signals from drones R The number of channel channels and the channel width are obtained; the process of calculating the number of channel channels NmuW is as follows:

[0009]

[0010] NumW = NumS + 1.

[0011] Furthermore, the channel width of the first channel to the channel width of the NumS-1th channel in the plurality of channel channels is BW. T The channel width of the NumSth channel is BW R .

[0012] Furthermore, the NmuWth channel among the plurality of channel channels is in a floating state.

[0013] Furthermore, a method for operating a device for automatically controlling the sensitivity of a signal detection channel includes the following steps:

[0014] S1-1, The control module switches the multi-channel receiving channel to the NumW-th channel, and the processing module samples the current base noise to obtain the average amplitude of the base noise;

[0015] S1-2, The control module switches the multi-channel receiving channel to the NumS-th channel, and the processing module samples the current ambient noise to obtain the average amplitude of the ambient noise.

[0016] S1-3. When the average amplitude of the ambient noise minus the average amplitude of the base noise is greater than or equal to a set fixed threshold, the surrounding environment is determined to be a complex electromagnetic environment; when the average amplitude of the ambient noise minus the average amplitude of the base noise is less than the set fixed threshold, the surrounding environment is determined to be a non-complex electromagnetic environment.

[0017] S1-4. When the surrounding environment is a complex electromagnetic environment, the control module controls the multi-channel receiving channel module to switch between the first channel channel and the NumS-1 channel channel; when the surrounding environment is a non-complex electromagnetic environment, the control module fixes the multi-channel receiving channel module to the NumS channel channel.

[0018] S1-5. When the timing from the start of step S1-1 reaches the set time T, the timing is reset and step S1-1 is executed again until step S1-4.

[0019] Beneficial Effects: This invention provides an apparatus and method for automatic sensitivity control of a signal detection channel, which can be implemented in radio frequency analog circuits or digital receiving circuits. By detecting ambient noise levels in near real-time, the receiving channel can be adaptively switched, enabling the use of a low-sensitivity receiving channel in complex electromagnetic environments to filter near-frequency interference and clutter, thus improving anti-interference performance. In relatively ideal electromagnetic environments, a high-sensitivity receiving channel can be used, increasing detection range. Furthermore, it can be applied to the detection of other related and similar communication signals, improving the success rate of radio detection of non-cooperative target signals. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a device for automatic control of the sensitivity of the signal detection channel. Detailed Implementation

[0021] The invention will now be further described with reference to the accompanying drawings.

[0022] like Figure 1As shown, a device for automatic sensitivity control of a signal detection channel includes a control module 3, a processing module 2, and a multi-channel receiving channel module 1. The input of the multi-channel receiving channel 1 is connected to a signal receiving antenna module 6, and the output of the multi-channel receiving channel module 1 is connected to the input of the processing module 2. The output of the processing module 2 is connected to the input of the control module 3. The multi-channel receiving channel module 1 includes several channel channels. The processing module 2 determines the complexity of the electromagnetic environment surrounding the signal receiving antenna module 6 based on the signal output from the multi-channel receiving channel module 1 and outputs the determination result to the control module 3. The control module 3 controls the corresponding channel channels among the several channel channels to connect the signal receiving antenna module 6 to the processing module 2 according to the signal output from the processing module 2. The control module 3 can be a microcontroller or a complex logic device, while the processing module 2 at least includes a signal acquisition circuit and is composed of a processor circuit capable of performing a fast Fourier transform. The processing module 2 also performs simple processing on the acquired signal before transmitting it to a subsequent processing module or terminal.

[0023] The determination of the channel width and the number of channels is related to two parameters: the operating bandwidth range of the UAV's detected signal and the bandwidth of the UAV's detected signal itself. The operating bandwidth range of the UAV's detected signal is the difference between the upper and lower limits of the possible frequency domain of the UAV's detected signal. The bandwidth of the UAV's detected signal itself is the difference between the upper and lower limits of the instantaneous frequency domain of each target UAV. Since there are many types of UAVs, the bandwidths of the detected signals of several UAVs form a bandwidth sequence BW, which is a real number sequence.

[0024] BW = BW T1 BW T2 , ......BW Ti , ......, BW Tn ]

[0025] Once the type of consumer drone is determined, the bandwidth of the signal being detected from the drone is determined, denoted as BW. T The bandwidth (BW) of the signal detected by the drone itself. T The operating bandwidth range (BW) of the detected signals from drones R The number of channel channels and the channel width are obtained; the process of calculating the number of channel channels NmuW is as follows:

[0026]

[0027] NumW = NurmS + 1.

[0028] The channel width of the first channel to the channel width of the NumS-1th channel in the plurality of channel channels is BW. TThe channel width of the NumSth channel is BW R The NmuWth channel among the aforementioned channel channels is in a floating state.

[0029] The input terminals of several channel channels are connected to the signal receiving antenna module 6 via the first channel switch module 4, and the output terminals of several channel channels are connected to the input terminals of the processing module 2 via the second channel switch module 5. The first channel switch module 4 is a signal input or output controlled circuit. The input signal of the first channel switch module 4 is provided by the signal receiving antenna module 6, and the output signal of the first channel switch module 4 is fed to one of the corresponding channel channels through different channel channels. However, at any given time, only one output channel and its corresponding channel have output. Similarly, the second channel switch module 5 is also a signal input or output controlled circuit. The input signal of the second channel switch module 5 is provided by several channel channels, and the output signal of the second channel switch module 5 is controlled to select one channel to output to the processing module 2. At any given time, only one output channel and its corresponding channel have output. The processing module 2 performs simple processing on the signal and then transmits it to a terminal such as a computer.

[0030] The first channel switch module 4 and the second channel switch module 5 enable the selection and switching between different channels. The core parameter of both modules is the number of switch channels, NumW, which is the same as the number of channel channels. The first channel switch module 4 and the second channel switch module 5 can be numerically controlled RF switch chips or logic switches for digital channels, and the design can be selected according to actual needs. Channel switching can be controlled in various ways, such as using a microcontroller or complex logic devices to control the channel opening of the numerically controlled RF switch chip to achieve channel switching; if it is a digital channel, channel switching can be achieved through gate circuits or flip-flops in a digital processing chip or complex logic device; if a numerically controlled switch is used, the number of control quantities is Y.

[0031] Y = rounded up [log2(NumW)].

[0032] Each of the first channel switch module 4 and the second channel switch module 5 is provided with a first switch channel and a second switch channel corresponding to any one of the plurality of channel channels; the control module 3 controls the first switch channel and the second switch channel corresponding to any one of the plurality of channel channels to open, so that any one channel channel connects the signal receiving antenna module 6 and the processing module 2. At the same time, only one of the plurality of channel channels connects the signal receiving antenna module 6 and the processing module 2; the control of the first channel switch module 4 and the second channel switch module 5 is controlled by a single controller of the control module 3, and the control variables are also the same; the multi-channel receiving channel module 1 is a combination of the first channel switch module 4, the second channel switch module 5 and a plurality of channel channels. The external input signal first enters the first channel switch module 4 through the signal receiving antenna module 6, the plurality of switch channels of the first channel switch module 4 are interconnected with the plurality of channel channels, and then the output of the plurality of channel channels is interconnected with the plurality of switch channels of the second channel switch module 5.

[0033] A method for operating a device for automatically controlling the sensitivity of a signal detection channel includes the following steps:

[0034] S1-1, Control module 3 switches the multi-channel receiving channel 1 to the NumWth channel channel. At the same time, processing module 2 samples the current base noise and performs a fast Fourier transform. Then, it calculates the amplitude of each element in the obtained Fourier transform result sequence to obtain the amplitude sequence of the base noise. Finally, it calculates the average value of all elements in the amplitude sequence of the base noise to obtain the average amplitude As of the base noise.

[0035] Processing module 2 can perform analog-to-digital conversion on the base noise signal sent from the receiving channel through an analog-to-digital conversion circuit, and extract a base noise sequence S of no less than 4096 points from it. The base noise sequence S is a numerical sequence composed of no less than 4096 real or complex numbers.

[0036] S = {X1, X2, X3, ..., X} n ......X N ]

[0037] In the formula, N is the number of elements in the sequence, N≥4096;

[0038] Then, the same number of points are used to perform a Fast Fourier Transform (FFT) on the basis noise sequence S, that is, an FFT is performed on each element of the basis noise sequence S to obtain the result sequence S. FFT The sequence is a complex sequence; the formula for calculating the FFT is:

[0039]

[0040] SFFT ={X1,X2,X3......X k ......x K ]

[0041] In the formula, k is the result sequence S FFT The index of the k-th element, is the rotation factor, where j is the imaginary unit.

[0042] For the resulting sequence S FFT The amplitude of each complex element is calculated to obtain the amplitude sequence A of the basis noise. FFT The sequence is a sequence of positive real numbers; the formula for calculating the amplitude is:

[0043]

[0044] A FFT = [A1, A2, A3...A k ......A K ]

[0045] In the formula, X k For any complex element in the resulting sequence, For X k The real part, For X k The imaginary part.

[0046] S1-2, Control module 3 switches multi-channel receiving channel 1 to the NumSth channel channel. Processing module 2 samples the current ambient noise and performs a fast Fourier transform. Then, it calculates the amplitude of each element in the obtained Fourier transform result sequence to obtain the amplitude sequence of ambient noise. Finally, it calculates the average value of all elements in the amplitude sequence of ambient noise to obtain the average amplitude Ah of ambient noise.

[0047] Processing module 2 can perform analog-to-digital conversion on the base noise signal sent from the receiving channel through an analog-to-digital conversion circuit, and extract an environmental noise sequence Sv of no less than 4096 points from it. The environmental noise sequence Sv is a numerical sequence composed of no less than 4096 real or complex numbers.

[0048] Sv = [Xv1, Xv2, Xv3, ..., Xv] n ......Xv N ]

[0049] In the formula, N is the number of elements in the sequence, N≥4096;

[0050] Then, the same number of points are used to perform a Fast Fourier Transform (FFT) on the environmental noise sequence Sv, that is, an FFT is performed on each element of the environmental noise sequence Sv to obtain the result sequence Sv. FFT The sequence is a complex sequence; the formula for calculating the FFT is:

[0051]

[0052] Sv FFT =[X v1 X v2 X v3 ......Xv k ......Xv K ]

[0053] In the formula, k is the result sequence Sv FFT The index of the k-th element, is the rotation factor, where j is the imaginary unit.

[0054] For the resulting sequence Sv FFT The amplitude of each complex element is calculated to obtain the amplitude sequence Av of the environmental noise. FFT The sequence is a sequence of positive real numbers; the formula for calculating the amplitude is:

[0055]

[0056] Av FFT =[Av1, Av2, Av3......Av k ......Av K ]

[0057] In the formula, Xv k For any complex element in the resulting sequence, For Xv k The real part, For Xv k The imaginary part.

[0058] S1-3. A fixed threshold is used to determine whether the ambient noise exceeds a certain threshold value. Depending on the performance of each receiver design, a fixed threshold can be set, or the threshold can be flexibly adjusted according to the system complexity. Taking a fixed threshold as an example, this fixed threshold is set to 12 dB. When the average amplitude of the ambient noise Ah minus the average amplitude of the floor noise As is greater than or equal to the set fixed threshold, the surrounding environment is determined to be a complex electromagnetic environment, meaning the electromagnetic environment around the signal receiving antenna module 6 is highly complex. The determination conditions are as follows:

[0059] Ah-As≥12dB

[0060] When the average amplitude of the ambient noise Ah minus the average amplitude of the floor noise As is less than a set fixed threshold, the surrounding environment is determined to be a non-complex electromagnetic environment, meaning the electromagnetic environment around the signal receiving antenna module 6 has low complexity. The determination criteria are as follows:

[0061] Ah-As < 12dB

[0062] S1-4. When the surrounding electromagnetic environment is complex, the control module 3 controls the multi-channel receiving module 1 to switch between the first channel and the NumS-1th channel, sacrificing the receiving channel sensitivity to suppress co-channel or near-channel interference. The corresponding channel transmits the signal received or detected by the corresponding signal receiving antenna module 6 to the processing module 2. The processing module 2 samples the signal from the corresponding channel, performs simple processing, and sends it to the detection processing system, i.e., the computer terminal. When the surrounding electromagnetic environment is not complex, the control module 3 fixes the multi-channel receiving module 1 to the NumSth channel to maximize the receiving channel sensitivity and increase the detection distance. The corresponding channel transmits the signal received or detected by the corresponding signal receiving antenna module 6 to the processing module 2. The processing module 2 samples the signal from the corresponding channel, performs simple processing, and sends it to the detection processing system, i.e., the computer terminal. Real-time monitoring of the current electromagnetic environment or electromagnetic complexity surrounding the signal receiving antenna module 6 allows for automatic switching of channels with different sensitivities among several channels, achieving automatic control of switching between channels with different sensitivities based on the electromagnetic complexity surrounding the signal receiving antenna module 6, adapting to different electromagnetic complex environments.

[0063] S1-5. Set a fixed time period T. When the timing from the start of step S1-1 reaches the set time T, the timing is reset and steps S1-1 to S1-4 are executed again. The set time period T can be used after the control module 3 switches between several channel channels to perform signal acquisition or signal transmission for a period of time after the electromagnetic complexity around the signal receiving antenna module 6 is judged, and then the electromagnetic complexity around the signal receiving antenna module 6 is judged again after the time period T is reached.

[0064] Example

[0065] Taking an unknown consumer-grade drone signal as an example, the drone's image transmission signal bandwidth is 10MHz, operating in the frequency range of 2400MHz-2483MHz; in this implementation example, the bandwidth of the drone's detected signal itself is BW. T =10M, the operating bandwidth range of the UAV's detected signal is 2483MHz-2400MHz=83M. The number of channel channels (NumW) in multi-channel receiving module 1 is 18;

[0066]

[0067] NumW = NumS + 1 = 18

[0068] The channel width of the 1st channel, the 2nd channel, ... the 16th channel is BW = 10M, the channel width of the 17th channel is 83M, and the 18th channel is in a floating state; the number of switching channels of the two channel switches is the same as the number of channel channels, which is 18; here, a numerically controlled RF switch chip is selected as the channel switch, and the switching of the channel switch is controlled by a complex logic device to realize the channel switching. The number of control quantities of the numerically controlled switch = rounded up [log2(NumW)] = 5 bits.

[0069] First, the control module 3 switches the multi-channel receiving channel module 1 to the NumWth channel, which is in a floating state. At the same time, the processing module 2 is notified to perform current floor noise sampling and fast Fourier transform. Then, the amplitude of the obtained Fourier transform result sequence is calculated. Finally, the average value of the amplitude sequence is calculated to obtain the average floor noise As = 33dBm.

[0070] Then, the control module 3 switches the multi-channel receiving channel module 1 to the NumS channel; at the same time, the processing module 2 is notified to perform current noise sampling and fast Fourier transform, and then the amplitude of the obtained Fourier transform result sequence is calculated. Finally, the average value of the amplitude sequence is calculated to obtain the average value of the environmental noise Ah = 40dBm.

[0071] A fixed threshold of 12 dB is set. If 40 dBm - 33 dBm < 12 dB, it is determined to be a non-complex electromagnetic environment, that is, the electromagnetic complexity around the signal receiving antenna module 6 is low. The control module 3 fixes the multi-channel receiving channel module 1 on the 16th channel. The processing module 2 samples the signal of the corresponding channel, performs simple processing, and sends it to the detection and processing system, that is, the computer terminal.

[0072] The above description is merely a preferred embodiment of the present invention. Those skilled in the art can make several modifications and optimizations based on the above disclosure without departing from the basic principles described above. These modifications and optimizations should be considered within the scope of protection as understood by the present invention.

Claims

1. A device for automatic control of the sensitivity of a signal detection channel, characterized in that: The system includes a control module (3), a processing module (2), and a multi-channel receiving channel module (1). The input of the multi-channel receiving channel module (1) is connected to the signal receiving antenna module (6), and the output of the multi-channel receiving channel module (1) is connected to the input of the processing module (2). The output of the processing module (2) is connected to the input of the control module (3). The multi-channel receiving channel module (1) includes several channel channels. The processing module (2) judges the complexity of the electromagnetic environment around the signal receiving antenna module (6) based on the signal output by the multi-channel receiving channel module (1) and outputs the judgment result to the control module (3). The control module (3) controls the corresponding channel channels in the several channel channels to connect the signal receiving antenna module (6) and the processing module (2) according to the signal output by the processing module (2). The bandwidth (BW) of the signal detected by the drone itself T The operating bandwidth range (BW) of the detected signals from drones R The number of channel channels and the channel width are obtained; the process of calculating the number of channel channels NmuW is as follows: ； ； The channel width of the first channel to the channel width of the NumS-1th channel in the plurality of channel channels is BW. T The channel width of the NumSth channel is BW. R ; The NmuWth channel among the aforementioned channel channels is in a floating state; Use the device to perform the following steps: S1-1, The control module (3) switches the multi-channel receiving channel module (1) to the NumW channel, and the processing module (2) samples the current base noise to obtain the average amplitude of the base noise; S1-2, The control module (3) switches the multi-channel receiving channel module (1) to the NumS channel, and the processing module (2) samples the current ambient noise to obtain the average amplitude of the ambient noise; S1-3. When the average amplitude of the ambient noise minus the average amplitude of the base noise is greater than or equal to a set fixed threshold, the surrounding environment is determined to be a complex electromagnetic environment; when the average amplitude of the ambient noise minus the average amplitude of the base noise is less than the set fixed threshold, the surrounding environment is determined to be a non-complex electromagnetic environment. S1-4. When the surrounding environment is a complex electromagnetic environment, the control module (3) controls the multi-channel receiving channel module (1) to switch between the first channel channel and the NumS-1 channel channel; when the surrounding environment is a non-complex electromagnetic environment, the control module (3) fixes the multi-channel receiving channel module (1) to the NumS channel channel. S1-5. When the timing from the start of step S1-1 reaches the set time T, the timing is reset and step S1-1 is executed again until step S1-4.

2. The device for automatic control of signal detection channel sensitivity according to claim 1, characterized in that: The input terminals of several channel channels are connected to the signal receiving antenna module (6) through the first channel switch module (4), and the output terminals of several channel channels are connected to the input terminals of the processing module (2) through the second channel switch module (5).

3. The device for automatic control of signal detection channel sensitivity according to claim 2, characterized in that: The first channel switch module (4) and the second channel switch module (5) are each provided with a first switch channel and a second switch channel corresponding to any one of the channel channels; the control module (3) controls the first switch channel and the second switch channel corresponding to any one of the channel channels to open, so that any one channel connects the signal receiving antenna module (6) and the processing module (2).

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