CN106209296A - A kind of band signal EVAC - Google Patents

Abstract

The invention relates to a band signal interference system. It can be applied to signal interference in a large-area multi-point range, realize wide-band signal interference, and realize a wide range of interference, remote real-time intelligent monitoring and system self-inspection. The signal interference system includes a host computer main control part (1), a wireless bridge (2), a master wireless AP (5), a plurality of slave wireless APs (6) and an interference device (7); the wireless bridge (2) includes The bridge A terminal (3) and the network bridge B terminal (4); after the main control part (1) of the upper computer sends the control command, the control command is sent to each interference device (7) through the wireless bridge (2) and the wireless AP After the microprocessor (11) in the interference device receives the control instruction from the main control part (1) of the host computer through the WIFI antenna (8) and the wireless module (9), the microprocessor (11) configures the interference according to the requirements of the instruction Signal source one (12) and interference signal source two (13) realize interference.

Description

A band signal jamming system

technical field

The invention belongs to the technical field of communication, and in particular relates to a band signal interference system. It can be applied to signal interference in a large area.

Background technique

From the perspective of the development requirements of modern society, ensuring the security of oneself and the country is the premise of social development, and information security, as a key link in building a security environment for oneself and the country, has been paid more and more attention by the state and society. Therefore, in many environments, interference devices are used to interfere with signals in a certain band, so as to achieve the safety protection of signals in the environment.

At present, the interference band of the existing interference system is between 800MHz-2.2GHz, and the interference objects are the downlink signals of 2G\3G\4G mobile phones. Purpose. However, taking the exam as an example, this type of jammer also has the following shortcomings:

1. The cheating methods in the examination room are mainly digital transmission information (such as SMS eraser) and voice information (such as rice earphones) with a frequency of less than 800MHz, and WIFI signals with a frequency of 2.4G. The existing jammers cannot play a shielding effect and are prone to Cheating situation.

2. The output power of the existing jammers is generally 25dBm, and the coverage is limited. Therefore, the "one room, one jammer" jamming mode is adopted in the test in which one classroom is equipped with one jamming device. In a large-scale examination like the college entrance examination, there are tens of thousands of examination rooms in an urban area, and tens of thousands of interference devices need to be equipped. The storage and transportation of these interference devices have increased the work difficulty of the invigilation center and the examination staff.

3. In the traditional "one room, one" jamming mode, due to uncontrollable reasons such as jammer batches, workmanship, and transportation, it is difficult to guarantee the qualified rate of jammers. In addition, the currently used jamming systems do not have self-checking functions, which makes the test The staff or the proctoring center cannot judge whether the equipment is working normally, which makes some classrooms fail to meet the test requirements, which affects the fairness and seriousness of the test.

4. Once the existing interference equipment is manufactured, the interference band and mode have been fixed, and it interferes with all signals in the corresponding band during operation, and cannot be configured. In this way, during the test, if the communication frequency of the communication equipment used by the test staff is within the interference range of the jammer (such as: point-to-point communication equipment), it will also fail.

Contents of the invention

The purpose of the present invention is to provide a band signal interference system that realizes wide band signal interference, and can conveniently configure its working band and working mode through the network, and realizes a wide range of interference, remote real-time intelligent monitoring and system self-inspection.

The technical solution of the present invention is that a band signal interference system includes a host computer main control part, a wireless bridge, a master wireless AP, multiple slave wireless APs and interference devices; the wireless bridge includes a bridge A end and a bridge B end ; The main control part of the host computer is wired to the bridge A end, and the bridge B end is wired to the main wireless AP, and all the slave wireless APs are wirelessly connected to the main wireless AP through the WIFI network; each wireless AP passes WIFI network and multiple interfering devices;

The function of the main control part of the upper computer is that the main control part of the upper computer receives the control instructions of the operator and transmits the control instructions to the wireless bridge; the main control part of the upper computer receives the suspicious frequency point information from the interference Information and use the signal field strength positioning method to determine the location of the cheating signal source, and issue interference control instructions to the corresponding interference equipment;

The wireless bridge is responsible for realizing the wireless information transmission between the main control part of the upper computer and the main wireless AP;

The master wireless AP and multiple slave wireless APs are used for signal transmission between the wireless bridge and the interference device;

The interference device performs signal interference according to the control signal. At the same time, the interference device searches and receives the band signal within the range, judges and determines the suspicious frequency points in the band signal within the range, and transmits the frequency and power of the suspicious frequency points to the corresponding wireless AP.

Described interfering equipment comprises microprocessor, wireless module, WIFI, receiving module and transmitting module; WIFI antenna is wired connection with wireless module, and wireless module, wired interface, transmitting module and receiving module are all connected with microprocessor; The function is to transmit an interference signal according to the control command, and the function of the receiving module is to monitor suspicious frequency points within the range, the microprocessor receives the control command, and sends the control command to the transmitting module, and the microprocessor judges and determines the suspicious frequency point at the same time. Frequency band, and send the frequency and power of all suspicious frequency points back to the main control part of the host computer through the wireless module.

Described transmitting module comprises interference signal source one, interference signal source two, radio frequency power amplifier and transmitting antenna; Interference signal source one and interference signal source two are all wired with microprocessor, the output terminal of interference signal source one, interference signal source two The output ends of the radio frequency power amplifier are connected to the transmitting antenna, and the transmitting antenna emits interference signals; the interference signal source 1 is mainly used to interfere with voice signals and digital transmission signals, and the interference signal source 2 is mainly used to interfere with mobile phone and WIFI signals.

The receiving module includes a receiving antenna, a low-noise amplification module, a down-mixer, a low-pass filter, an automatic gain control, an A/D conversion module, and an external memory; the receiving antenna is connected to the low-noise amplification module, the down-mixer, Low-pass filter, automatic gain control and A/D conversion module, A/D conversion module and external memory are all connected to the microprocessor; low-noise amplification module makes the received signal obtain the maximum gain, and the down-mixer is to pass through The signal received by the receiving antenna is mixed and demodulated to obtain an intermediate frequency signal; the low-pass filter and the automatic gain control module amplify the received signal and filter out noise.

Described interference signal source one comprises a baseband signal generator, a local oscillator signal generator and a modulation circuit; one end of the baseband signal generator and one end of the local oscillator signal generator are all wired with the microprocessor, and the other end of the baseband signal generator The other end of the local oscillator signal generator is connected to the modulation circuit, and the modulation circuit is connected to the radio frequency power amplifier by wire; the baseband signal generator generates a sinusoidal signal with a certain frequency width, and the local oscillator signal generator generates a carrier signal corresponding to the suspicious frequency point. The modulation circuit modulates the signal generated by the baseband signal generator and the signal generated by the local oscillator signal generator to generate an interference signal of a certain frequency band based on the suspicious frequency point.

The interference signal source two includes a voltage-controlled oscillator and a sawtooth wave generator; the microprocessor, the sawtooth wave generator, the voltage-controlled oscillator and the signal amplifier are wired in sequence; the sawtooth wave generator and the voltage-controlled oscillator work together to generate The frequency scanning signal in the working frequency band of the mobile phone or WIFI is amplified by the signal amplifier and RF power amplifier.

The beneficial effect of the present invention is,

1. The interference band is wide, realizing full-band interference from 1MHz to 2.4GHz; the interference method is more intelligent, and the interference method can also be selected through the configuration of the micro-processing, and supports frequency scanning and frequency hopping interference for the entire band, and the band white can be set List and blacklist, the band system in the white list will automatically skip without interference; the band system in the black list will focus on interference; for WIFI signals, the system only reserves 1 channel for communication, and keeps interference to other channels.

2. The interference range is large. The interference signal is sent out through the omnidirectional antenna after passing through the two-stage power amplifier. The output power can reach 33dBm during normal operation, and the transparent transmission ability is strong. The effective interference area for the barrier-free open area can reach 2,000 square meters; In buildings with many steel-concrete partition walls such as ordinary teaching buildings and government office buildings, it can effectively shield the floor where the jammer is located. For occasions requiring signal shielding such as large-scale examinations and confidential meetings, only one interference device needs to be installed on the floor to meet the requirements.

3. It is easy to configure. Each jamming device has two configuration modes, namely wired configuration and wireless configuration. You can set the upper limit frequency, lower limit frequency, interference mode, interference time, and interference black/white list of the jammer. It is only necessary to set up the device once, and the system will automatically work according to the latest configuration mode when it is turned on again.

4. Super remote control, real-time monitoring. Use the wireless AP to cover the area to be shielded. The jammers within the coverage area are connected to the wireless AP through the wireless network module. The wireless APs form a jamming network through wireless cascading. The main wireless AP is wired to the wireless bridge to communicate with the control center. The control center observes the working conditions of each jammer through the network, and then realizes the centralized management of all shielding devices at an ultra-long distance (up to about 20KM): such as on, off, and working status settings.

5. Program self-inspection, in the process of interfering with the equipment, if there are problems such as hardware circuit failure, unrecognizable control signal and other problems that affect the normal operation of the jammer, the main control chip will send a work failure command to the control center, and prompt the invigilator through the light alarm Personnel natively does not work.

6. Intelligent monitoring, searching and locating suspicious frequency points. When the jamming device is working, it will also scan nearby bands and determine whether there are suspicious frequency points. If suspicious frequency point interference is found, the device can automatically change the interference mode or send suspicious information to the control center through the network, and the center will configure it uniformly. The control center can locate the signal source of the cheating signal according to the suspicious signal information fed back by different interference nodes, and feed back the determined information to the public security department, which fully guarantees the fairness and seriousness of the exam. This working method not only breaks the working mode of traditional jammers, but also takes an important step towards future intelligent signal jamming.

Description of drawings

Fig. 1 is the structural representation of a kind of band signal jamming system of the present invention;

Fig. 2 is the working flow diagram of interference equipment in the present invention;

FIG. 3 is a schematic structural diagram of an interference device in the present invention;

Fig. 4 is a structural schematic diagram of interference signal source 1 in the present invention;

FIG. 5 is a schematic structural diagram of the interference signal source 2 in the present invention.

detailed description

The technical solution of the present invention will be further described in detail according to the drawings in the description.

As shown in Fig. 1, a kind of band signal interference system of the present invention comprises host computer main control part, 1 wireless network bridge 2, main wireless AP5 (wireless AP——wireless network access point), a plurality of from wireless AP6 and interference equipment 7. The wireless bridge 2 includes a bridge A terminal 3 and a bridge B terminal 4 . The main control part 1 of the upper computer adopts a computer.

The main control part 1 of the host computer and the bridge A end 3 in the wireless bridge 2 are connected by wire, that is, connected by a data line, and the bridge B end 4 in the wireless bridge 2 is connected by a wire with the main wireless AP5. At the same time, all the slave wireless AP6s are wirelessly connected to the main wireless AP5 through the WIFI network; each wireless AP is wirelessly connected to multiple interference devices 7 through the WIFI network, so all the interference devices 7 form an interference network, realizing the master control of the host computer Part 1 establishes direct communication between the host computer and each interference device through the connection between the wireless bridge 2 and the interference network.

The function of the host computer main control part 1 is, 1) the host computer main control part 1 receives the control instruction of the operator, and transmits the control instruction to the interference device 7 through the wireless network bridge 2, the main wireless AP and the slave wireless AP 6, thereby Interference is implemented by the interference device 7; the content of the control instruction includes interference mode setting and interference band setting; 2) the main control part 1 of the host computer receives the suspicious frequency point information from the interference device 7, and the suspicious frequency point information includes the frequency and power of the suspicious frequency point (The power represents the strength of the suspicious frequency point), the host computer main control part 1 determines the position of the cheating signal source according to the suspicious frequency point information and by the signal field strength RSS (Received SignalStrength) positioning method, and sends a signal to the corresponding interference device 7. Interference control instructions.

The communication information between the main control part 1 of the upper computer and the main wireless AP 5 is transmitted between the end 3 of the bridge A and the end 4 of the bridge B. Therefore, the wireless bridge 2 is responsible for realizing the long-distance wireless information transmission between the host computer main control part 1 and the main wireless AP5. Wireless bridge 2 chooses GCD-2400G industrial-grade wireless bridge, which has 300M bandwidth, 2.4G center frequency, supports IEEE802.11n transmission protocol, transmission rate is 300Mbps, and the longest transmission distance is 3 kilometers; it has radio frequency link test capability, so that It is easy to install and maintain, and can access 200 wireless AP nodes at the same time. The wireless bridge 2 adopts OFDM modulation technology, 2.4G/5.8GHz frequency band, complies with IEEE802.11n standard, and has the advantages of high speed and long distance. The wireless bridge 2 has a link integrity detection capability and a POE (Power over Ethernet) capability, thereby solving the power supply problem.

The master wireless AP 5 receives control commands from the main control part 1 of the host computer through the wireless network bridge 2, and forwards the control commands to each slave wireless AP 6 through WIFI. At the same time, it receives the information sent back from the wireless AP 6 and sends the received information back to the main control part 1 of the upper computer through the wireless bridge 2 .

The main wireless AP5 itself is wirelessly connected to a plurality of interfering devices 7 , and the main wireless AP5 directly sends control commands to each interfering device 7 within its range through WIFI signals. At the same time, receive the suspicious frequency point information sent back by each interference device 7 within the range, and send the suspicious frequency point information back to the main control part 1 of the upper computer through the wireless bridge 2 .

The slave wireless AP6 is responsible for receiving the control command sent by the master wireless AP5, and sends the control command to each interference device 7 within the range through the WIFI signal. At the same time, the suspicious frequency point information sent back by the interference device 7 is received, and the suspicious frequency point information is sent to the main wireless AP5.

The master wireless AP 5 and multiple slave wireless APs 6 implement signal transmission between the wireless bridge 2 and the interference device 7 .

The interference device 7 performs signal interference according to the control signal, that is, when the interference device 7 receives the control command generated by the main control part 1 of the upper computer sent by the corresponding wireless AP, it adjusts its own interference mode and interference frequency according to the control command, and implements signal interference. interference. At the same time, the interference device 7 searches and receives the band signals within the range, and judges and determines the suspicious frequency points in the band signals within the range. When the interference device 7 finds suspicious frequency points, it will package and compress the frequency and power information of the suspicious frequency points. , and transmit the packaged compressed data to the corresponding wireless AP, and send it back to the main control part 1 of the upper computer via the wireless AP and the wireless bridge 2. While receiving the control signal, the interfering device will also transmit its own operation status to the main control part 1 of the upper computer, so as to realize the monitoring of the operation status of the equipment by the recruitment center.

As shown in FIG. 3 , the interference device 7 includes a microprocessor 11 , a wired interface 10 , a wireless module 9 , a WIFI antenna 8 , a receiving module and a transmitting module. The WIFI antenna 8 is connected to the wireless module 9, and the wireless module 9, the wired interface 10, the transmitting module and the receiving module are all connected to the microprocessor 11. The function of the transmitting module is to transmit interference signals according to control instructions, and the function of the receiving module is to monitor suspicious frequency points within the range. The wired interface 10 adopts a type A USB female connector.

The function of the microprocessor 11 is to receive the control instructions from the main control part 1 of the upper computer through the wireless module 9, realize the configuration of the interference signal source 1 and the interference signal source 2; and judge and determine the suspicious frequency band at the same time. That is to perform Fourier transform FFT, band comparison and suspicious frequency point packaging. Carry out fast Fourier transform to the digital signal input by A/D conversion module 20, obtain the frequency domain characteristic of this signal, and filter out the band exceeding the threshold according to the preset signal amplitude threshold value (the preset signal refers to Need to interfere with the signal in the band range outside the whitelist in the environment; the amplitude threshold refers to the signal strength of each band), and compare these bands one by one with the existing safe bands in the external memory 21 (the bands that need to be used normally in the interference environment) In comparison, if there are other frequencies other than the safe band, it is judged as a suspicious frequency point, and finally the frequency, power and other information of all suspicious frequency points are packaged and compressed and sent back to the main control part 1 of the host computer through the wireless module 9 . The main control part 1 of the upper computer uses the RSS (Received Signal Strength) positioning method to determine the location of the cheating signal source. What described microprocessor 11 adopted is the Spartan 6 series FPGA chip of Xilinx Company.

The function of the microprocessor 11 is to receive the control instructions of the host computer main control part 1 through the wireless module 9, and realize the configuration of the interference signal source one and the interference signal source two; simultaneously, the A/D conversion module 20 in the receiving module Fast Fourier transform is performed on the input digital signal to obtain the frequency domain characteristics of the signal, and these bands are compared with the existing safe bands in the external memory 21 one by one. point, and pack and compress information such as frequency and power of all suspicious frequency points and send them back to the main control part 1 of the host computer through the wireless module 9.

As shown in FIG. 3 , the transmitting module includes an interference signal source one 12 , an interference signal source two 13 , a radio frequency power amplifier 14 and a transmitting antenna 15 . WIFI antenna 8 is wired connection with wireless module 9, and wireless module 9, interference signal source one 12, interference signal source two 13 and wired interface 10 are all wired connection with microprocessor 11, the output terminal of interference signal source one 12, interference signal The output ends of the source two 13 are all connected to the transmitting antenna 15 through the radio frequency power amplifier 14 . Interference signal source one 12 is mainly used for interfering with voice signals and digital transmission signals. Interference signal source 2 13 is mainly used to interfere with mobile phone and WIFI signals. The microprocessor 11 operates the interference signal source one 12 and the interference signal source two 13 in the transmission module according to the control command, so that the interference signal source one 12 and the interference signal source two 13 produce interference signals that meet the frequency requirements, and the interference signals pass through the radio frequency After the power amplifier 14 is amplified, it is transmitted to the space by the transmitting antenna 15 to achieve the purpose of interference.

As shown in FIG. 3 , the receiving module includes a receiving antenna 55 , a low-noise amplifier module 16 , a down-mixer 17 , a low-pass filter 18 , an automatic gain control 19 , an A/D conversion module 20 and an external memory 21 . The receiving antenna 55 is sequentially connected to the low noise amplifier module 16 , the down-mixer 17 , the low-pass filter 18 , the automatic gain control 19 and the A/D conversion module 20 . Both the A/D conversion module 20 and the external memory 21 are connected to the microprocessor 11 . In the receiving module, the low-noise amplifier module (LNA) 16 can enhance the received signal level within a certain range, and make the signal obtain the maximum gain without adding too much noise. The down-mixer 17 mixes and demodulates the signal received by the receiving antenna 55 to obtain an intermediate frequency signal. The low-pass filter 18 and the automatic gain control module (AGC) 19 are important components in the demodulation equipment, which amplify the received signal and filter out noise. The A/D conversion module 20 converts the received analog signal into a digital signal. The external memory 21 prestores frequency blacklists and whitelists. The bands that are normally used in the interfered environment are the white list, that is, the bands that do not allow interference are the white list, such as aviation bands and public service bands. Suspicious frequency points are blacklisted.

As shown in FIG. 4 , the interference signal source one 12 includes a baseband signal generator 23 , a local oscillator signal generator 24 and a modulation circuit 25 . One end of the baseband signal generator 23 and one end of the local oscillator signal generator 24 are all wired with the microprocessor 11, and the other end of the baseband signal generator 23 and the other end of the local oscillator signal generator 24 are all connected with the modulation circuit 25, The modulation circuit 25 is connected with the radio frequency power amplifier 14 by wire.

The baseband signal generator 23 selects the AD9854 chip of ADI Company. The chip adopts DDS technology, integrates two high-speed, high-performance orthogonal D/A converters on-chip, and can output I and Q two-way synthetic signals through digital programming. Driven by a high-stability clock, the AD9854 produces a sinusoidal signal with a certain frequency width.

The local oscillator signal generator 24 selects the frequency synthesizer ADF4350 of ADI Company, ADF4350 has an integrated voltage control oscillator (VCO), and its fundamental wave output frequency range is 2200MHz to 4400MHz. The local oscillator signal generator 24 generates a carrier signal corresponding to the suspicious frequency point. The baseband signal generator 23 and the local oscillator signal generator 24 work together to generate a signal of a certain frequency band based on the suspicious frequency point.

The modulation circuit 25 includes signal frequency conversion and signal conditioning. The signal frequency conversion of the modulation circuit 25 adopts the quadrature up-conversion modulation mode with ADL5385 as the core. Divide the signal into two channels, one with a phase shift of 90° and one with no phase shift, so that the carrier is divided into a pair of mutually orthogonal signals, and a pair of mutually orthogonal signals are respectively the same frequency as the two channels but with a phase difference The frequency band signals generated by the 90° (orthogonal) baseband signal generator 23 are mixed, and finally the results of the two channels are added by an adder to obtain an up-conversion mixed frequency signal. The signal conditioning of the modulation circuit 25 refers to high-frequency signal amplification, and the high-frequency signal amplification uses the 20dBRF/IF gain module ADL5602 from 50MHz to 4GHz. The device operates up to 4GHz and provides the highest dynamic range through internally matched gain blocks. The ADL5602 provides 20dB of gain, and the internal input and output are matched to 50Ω resistors for good device consistency. The modulation circuit 25 then amplifies and gains the up-conversion mixed signal to form an interference signal in a suspicious band.

As shown in FIG. 5 , the interference signal source 2 13 includes a voltage-controlled oscillator 27 and a sawtooth wave generator 26 . The microprocessor 11, the sawtooth wave generator 26, the voltage-controlled oscillator 27 and the signal amplifier 28 are wired in sequence. The output signal of the voltage controlled oscillator 27 is amplified by the signal amplifier 28 and then input to the radio frequency power amplifier 14 . Utilize sawtooth wave generator 26 to control voltage-controlled oscillator 27, make it generate the sweeping signal in the working frequency band of mobile phone or WIFI, described sweeping signal is amplified by transmitting antenna 15 after signal amplifier 28, radio frequency power amplifier 14 two stages Launched into the space, it can form garbled code interference in the received message signal of the mobile phone. The mobile phone cannot detect the normal data sent from the base station, so that the mobile phone cannot establish a connection with the base station, thereby realizing mobile phone interference. The same principle can destroy the WIFI receiver and Data exchange between routers for jamming purposes.

The present invention designs corresponding interference modes for different forms of cheating signals that need to be interfered. The voice cheating signal is interfered by frequency scanning, and the interference signal is continuously added to the cheating frequency band, so that the voice information cannot be listened to; the digital transmission signal is interfered in the form of frequency hopping, and the digital transmission scrambling code is sent to ensure that the receiver cannot Demodulate the cheating information to prevent cheating.

All antennas are 2.4G high-gain grid-shaped passive antennas, which are parabolic directional antennas with a gain of 27dBi.

All interfering devices 7 receive control signals from the host computer main control part 1 through the WIFI antenna 8, and send the suspicious frequency point data in the wireless module 9 to the host computer main control part 1 through the WIFI antenna 8.

The external interface of the interference device is divided into a wireless interface and a wired interface. The wireless interface includes a WIFI antenna 8 and a wireless module 9, responsible for sending and receiving WIFI information. The wired interface 10 is set as an A-type USB female head, and the computer installed with the main control part of the host computer can be connected to the interference device 7 in a wired manner, and the interference device 7 is configured one-to-one.

As shown in Figure 2, the work flow of interference device 7 among the present invention: when interference device 7 starts to work, 1, at first the microprocessor 11 in the interference device 7 initializes self equipment, initialization content comprises: 1) Processor 11 sets the initial frequency and initial working mode of interference signal source one and interference signal source two; 2) microprocessor 11 enables wireless module 9, makes wireless module 9 search nearby wireless AP; 3) microprocessor 11 enables A/D conversion module; 4) The microprocessor 11 reads the security band information stored in the external memory. 2. Then the interfering device 7 requests the wireless AP to assign an IP address to it. If the IP address is assigned successfully, it means that the interfering device is successfully connected to the wireless AP. If the address assignment fails, the interfering device sends a connection failure alarm signal and requests the wireless AP for address assignment again. , until successfully connected to the wireless AP. 3. After the interference device 7 is successfully connected to the wireless AP, it sends back the current interference mode and interference band and other state parameters of its own device to the main control part of the upper computer through the wireless AP. If the data transmission has not been completed, it will transmit again until the data returns. After the transmission is completed and the data return is completed, the networking process of the interference device is completed. In this way, the wireless AP is used to cover the shielded area, so that all interfering devices 7 are connected to the corresponding network, and the main control part 1 of the host computer can directly set the working mode and working frequency band of the interfering device 7 .

Taking large-scale exams as an example, the existing WIFI transmission frequency ranges from 2401 to 2423MHz. The existing WIFI signal has 13 channels. Before the present invention is used, the WIFI signal in the interfered space is scanned by the interference device 7 to determine the channel of the WIFI signal in the space, and the channel of the WIFI signal is transmitted to the main control part 1 of the host computer. , an unused channel is selected by the operator as the communication channel of the present invention, the main control part 1 of the upper computer, the main wireless AP 5, the slave wireless AP 6 and the interference device will be determined on the communication channel, and the remaining channels will be kept by the interference device interference.

When the present invention is used, each interference device 7 is installed at the center of each floor of the teaching building, and the main control part of the upper computer is installed at the recruitment center. The main control part 1 of the upper computer sends interference control instructions to all interference devices 7 . The interference control command is transmitted to the master wireless AP 5 in the interference area through the wireless network bridge 2 , and the interference control command is then sent to each slave wireless AP 6 by the master wireless AP 5 . The master wireless AP 5 and the slave wireless AP 6 send interference control instructions to the interference device 7, and the interference device 7 sends out an interference signal.

The working process of the present invention is as follows: before working, firstly determine the existing WIFI signal band in the interference environment, determine the WIFI channel used for data transmission in the present invention and configure it in the wireless AP. Then, all the slave wireless AP6s are connected to the main wireless AP5 through WIFI signals, and each wireless AP is connected to multiple interfering devices 7 through WIFI. After the connection is successful, the interfering devices will send the initial state back to the host computer through the WIFI network. Finally, the interference device works in an initial state and is ready to receive control instructions from the host computer.

After the main control part 1 of the upper computer sends the control command, the control command is sent to each interference device 7 through the wireless bridge 2 and the wireless AP, and the microprocessor 11 in the interference device 7 receives the upper control command via the WIFI antenna 8 and the wireless module 9. After the main control part 1 controls the instruction, the microprocessor 11 configures the interference signal source 1 12 and the interference signal source 2 13 according to the requirements of the instruction, so as to realize the interference effect required by the control instruction.

When the microprocessor 11 in the interference device finds suspicious frequency points through the receiving module, the microprocessor 11 packs and compresses information such as frequency and power of all suspicious frequency points and sends them back to the host computer control device through the wireless module 9 . The main control part 1 of the host computer determines the position of the cheating signal source by measuring the signal field strength RSS (Received Signal Strength) positioning method.

Claims (6)

1. A band signal interference system is characterized in that: the signal interference system comprises a host computer main control part (1), a wireless bridge (2), a main wireless AP (5), a plurality of wireless APs (6) and Interfering equipment (7); Wireless bridge (2) comprises network bridge A end (3) and network bridge B end (4); Described upper computer main control part (1) and network bridge A end (3) are wired connected, bridge B (4) is connected to the main wireless AP (5) by wire, and all the slave wireless APs (6) are wirelessly connected to the main wireless AP (5) through the WIFI network; each wireless AP is connected to multiple wireless APs through the WIFI network. a jamming device (7); The function of the main control part (1) of the upper computer is that the main control part (1) of the upper computer receives the control instruction from the operator and transmits the control instruction to the wireless network bridge (2); the main control part (1) of the upper computer receives the control instruction from the operator According to the suspicious frequency point information of the interference device (7), the position of the cheating signal source is determined according to the suspicious frequency point information and the signal field strength positioning method, and an interference control command is issued to the corresponding interference device (7); The wireless bridge (2) is responsible for realizing the wireless information transmission between the host computer main control part (1) and the main wireless AP (5); The master wireless AP (5) and multiple slave wireless APs (6) are used for signal transmission between the wireless bridge (2) and the interference device (7); The interference device (7) performs signal interference according to the control signal. At the same time, the interference device (7) searches for and receives the band signals within the range, judges and determines the suspicious frequency points in the band signals within the range, and transmits the frequency and power of the suspicious frequency points to the corresponding wireless AP. 2. according to a kind of band signal interference system according to claim 1, it is characterized in that: described interference equipment (7) comprises microprocessor (11), wireless module (9), WIFI antenna (8), receiving module and Transmitting module; WIFI antenna (8) is wired connection with wireless module (9), and wireless module (9), wired interface (10), transmitting module and receiving module are all connected with microprocessor (11); The function of transmitting module is Transmit interference signals according to the control instruction, the function of the receiving module is to monitor suspicious frequency points within the range, the microprocessor (11) receives the control command, and sends the control command to the transmitting module, and the microprocessor (11) Judging and determining suspicious frequency bands, and sending the frequency and power of all suspicious frequency points back to the main control part (1) of the upper computer via the wireless module (9). 3. according to a kind of band signal jamming system according to claim 2, it is characterized in that: said transmitting module comprises jamming signal source one (12), jamming signal source two (13), radio frequency power amplifier (14) and transmitting antenna ( 15); Interference signal source one (12) and interference signal source two (13) are all wired with microprocessor (11), the output end of interference signal source one (12), the output end of interference signal source two (13) All are connected with transmitting antenna (15) through radio frequency power amplifier (14), and transmitting antenna (15) transmits interference signal; Interference signal source one (12) is mainly used in interference voice signal and digital transmission signal, and interference signal source two (13) mainly Used to interfere with mobile phone and WIFI signals. 4. according to a kind of band signal interference system according to claim 2, it is characterized in that: described receiving module comprises receiving antenna (55), low noise amplifying module (16), down-mixer (17), low-pass filter device (18), automatic gain control (19), A/D conversion module (20) and external memory (21); receiving antenna (55) is connected to low noise amplification module (16), down mixer (17), Low-pass filter (18), automatic gain control (19) and A/D conversion module (20), A/D conversion module (20) and external memory (21) are all connected with microprocessor (11); Low noise Amplifying module (16), makes the received signal obtain maximum gain; Down-mixer (17) is to carry out mixing demodulation to the signal received by receiving antenna (55), to obtain intermediate frequency signal; Low-pass filter (18 ) and the automatic gain control module (19) amplify the received signal and filter out noise. 5. according to a kind of band signal interference system according to claim 3, it is characterized in that: said interference signal source one (12) comprises baseband signal generator (23), local oscillator signal generator (24) and modulation circuit ( 25); one end of the baseband signal generator (23) and one end of the local oscillator signal generator (24) are wired with the microprocessor (11), and the other end of the baseband signal generator (23) and the local oscillator signal generator The other end of (24) is all connected with modulation circuit (25), and modulation circuit (25) is connected with radio frequency power amplifier (14) by wire; Baseband signal generator (23) produces the sinusoidal signal of certain frequency width, and local oscillator signal generator ( 24) produce the carrier signal corresponding to suspicious frequency point, modulation circuit (25) carries out quadrature modulation with the sinusoidal signal that baseband signal generator (23) produces and the carrier signal that local oscillator signal generator (24) produces, generates with suspicious Interference signals in a certain frequency band based on the frequency point. 6. according to a kind of band signal interference system according to claim 3, it is characterized in that: said interference signal source two (13) comprises voltage-controlled oscillator (27) and sawtooth wave generator (26); Microprocessor ( 11), the sawtooth wave generator (26), the voltage controlled oscillator (27) and the signal amplifier (28) are wired in sequence; the sawtooth wave generator (26) and the voltage controlled oscillator (27) work together to generate the The frequency sweep signal in the working frequency band, the frequency sweep signal is amplified by the signal amplifier (28) and the radio frequency power amplifier (14) to realize interference.