Distributed reconnaissance tool

Abstract

The invention discloses a distributed reconnaissance tool, relates to the technical field of voice interception, and aims to solve the problems of limited multi-node access capability, poor anti-interference performance and insufficient multi-target interception continuity of an existing reconnaissance system. The tool comprises a micro audio node network and a base station unit, a recording module, a wireless transmission module and an encryption module are arranged in the miniature audio node, local recording and remote transmission are supported, and the miniature audio node has the characteristics of water resistance and low power consumption; the base station unit adopts an orthogonal graph division multiple access technology, at most 32 micro audio nodes can be accessed, four paths of voice can be monitored in real time, the audio quality is optimized through a spectral subtraction voice enhancement algorithm, and WIFI / Ethernet connection and time synchronization and combination of multi-node recording files are also supported. According to the invention, approaching interception and multi-target centralized deployment and control of the moving target are realized, the stability, expansibility and practicability of the interception system are improved, and the method is suitable for scenes such as public security technical investigation and the like.

Description

Technical Field

[0001] This invention belongs to the technical field of voice reconnaissance and wireless communication, specifically relating to distributed reconnaissance tools. Background Technology

[0002] In fields such as technical reconnaissance and security protection, it is often necessary to conduct voice surveillance on moving targets or multiple fixed targets within a specific area to obtain critical information. Traditional voice surveillance tools are mostly deployed at a single point, which has the following shortcomings:

[0003] Limited multi-node access capability: Existing eavesdropping systems mostly use traditional one-dimensional multiple access technologies such as frequency division multiple access, time division multiple access, or code division multiple access. Affected by multipath propagation (interference caused by the superposition of signals after propagation through different paths) and Doppler frequency shift (signal frequency shift caused by target movement), the number of eavesdropping nodes that a single base station can access is relatively small, making it difficult to meet the needs of simultaneous deployment of multiple targets.

[0004] Insufficient anti-interference and confidentiality: Traditional multiple access technology has weak ability to suppress multipath interference and Doppler frequency shift, which can easily lead to packet loss and distortion in voice transmission; at the same time, the encryption level of conventional transmission protocols is low, and there is a risk of leakage of eavesdropped data.

[0005] Poor audio quality and monitoring continuity: The voice signals collected by the monitoring nodes are easily contaminated by environmental noise, and existing noise reduction technologies cannot balance sound quality and noise reduction effect; in addition, the recording files collected by multiple nodes lack a time synchronization mechanism, and information breaks are likely to occur when monitoring moving targets across nodes.

[0006] Deployment and maintenance are inconvenient: Existing listening nodes are large in size and consume a lot of power, and lack environmental adaptation designs such as waterproofing, making them inconvenient for rapid outdoor deployment; the efficiency of node battery charging, recording file download and other operations is low, affecting the continuous working capability of the system. Summary of the Invention

[0007] The purpose of this invention is to provide a distributed reconnaissance tool to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A distributed reconnaissance tool, comprising several miniature audio nodes and a base station unit, wherein the miniature audio nodes are wirelessly connected to the base station unit;

[0010] The miniature audio node includes a pickup module, a voice processing module, a recording module, an encryption module, and a first wireless transmission module connected in sequence, and also includes a low-power battery to power each module. The miniature audio node is equipped with a waterproof shell.

[0011] The base station unit includes a second wireless transmission module, a central control module, a voice enhancement module, a network communication module, and a storage module. The second wireless transmission module, the voice enhancement module, the network communication module, and the storage module are electrically connected to the central control module.

[0012] The second wireless transmission module uses orthogonal graph division multiple access technology to achieve communication connections with up to 32 of the miniature audio nodes, and supports simultaneous reception of real-time voice signals transmitted by 4 of the miniature audio nodes.

[0013] The central control module is used to send remote control commands to each of the miniature audio nodes, and to merge and store the received multi-node recording files after time synchronization to the storage module.

[0014] Preferably, the orthogonal graph division multiple access technology is based on frequency hopping graphs, and the second wireless transmission module and the first wireless transmission module control the carrier frequency hopping through a preset pseudo-random code, with the carrier frequency being a dedicated digital frequency point below 1GHz.

[0015] Preferably, the speech enhancement module employs a spectral subtraction algorithm, the implementation process of which includes:

[0016] The received noisy speech signal is transformed by FFT to the frequency domain while retaining the phase information;

[0017] Noise spectrum estimation is obtained through the initial "quiet segment" of the signal;

[0018] The enhanced speech power spectrum is obtained by subtracting the estimated noise spectrum from the speech signal spectrum in the frequency domain.

[0019] The retained phase information is combined with IFFT transformation to return to the time domain and output the enhanced speech signal.

[0020] Preferably, the encryption module uses the AES encryption algorithm to encrypt the recording files stored in the recording module and the voice data transmitted by the first wireless transmission module.

[0021] Preferably, the recording module of the miniature audio node uses a 32G SD card as the storage medium, supporting a recording duration of up to 2 months; the miniature audio node is also equipped with a battery charging dock and a node connection dock, the battery charging dock supports simultaneous charging of 8 batteries, and the node connection dock supports simultaneous downloading of recording files by 16 nodes.

[0022] Preferably, the network communication module supports both WIFI and Ethernet connections, enabling communication between the base station unit and external computers and mobile phones, allowing external devices to receive real-time voice signals, download audio files, and remotely control the system.

[0023] Preferably, the pickup module of the miniature audio node is a high-sensitivity, holeless vibration pickup microphone.

[0024] Preferably, the communication link between the first wireless transmission module and the second wireless transmission module is a bidirectional link, which can transmit digital voice signals and remote control commands simultaneously.

[0025] Compared with existing technologies, the present invention provides a distributed reconnaissance tool with the following advantages:

[0026] Significantly improved multi-node access and anti-interference capabilities: Orthogonal graph multiple access technology breaks through the limitations of traditional one-dimensional multiple access, enabling 32 nodes to access simultaneously. Furthermore, it effectively suppresses multipath interference and Doppler frequency shift through frequency hopping and orthogonal resource allocation, resulting in a significant improvement in transmission stability.

[0027] Continuity of listening and audio quality optimization: The time synchronization and file merging functions of the central control module solve the problem of information breakage when listening to moving targets across nodes; the spectral subtraction speech enhancement algorithm effectively reduces environmental noise, taking into account both sound clarity and auditory comfort;

[0028] High security and deployment flexibility: AES encryption algorithm ensures data security, waterproof and low power consumption design adapts to various indoor and outdoor scenarios, and disguised deployment and auxiliary docking station improve the system's practical applicability and maintenance efficiency.

[0029] Strong adaptability to multiple scenarios: It supports the combination of real-time listening and local recording, and the parallel detection and control of single and multiple targets. It can be widely used in fields such as technical investigation and security, filling the technical gap of existing reconnaissance tools in the control of moving targets and multiple targets. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the Frequency Division Multiple Access (FDMA) of the present invention.

[0031] Figure 2 This is a block diagram illustrating the principle of the spectral subtraction method of the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This invention provides, for example Figure 1-2 shown

[0034] The distributed reconnaissance tool consists of several miniature audio nodes and a base station unit, with the miniature audio nodes wirelessly connected to the base station unit.

[0035] The miniature audio node includes a pickup module, a voice processing module, a recording module, an encryption module, and a first wireless transmission module that are connected in sequence. It also includes a low-power battery that powers each module. The miniature audio node is equipped with a waterproof shell.

[0036] The base station unit includes a second wireless transmission module, a central control module, a voice enhancement module, a network communication module, and a storage module. The second wireless transmission module, the voice enhancement module, the network communication module, and the storage module are electrically connected to the central control module.

[0037] The second wireless transmission module uses orthogonal graph division multiple access technology to achieve communication connections with up to 32 miniature audio nodes and supports simultaneous reception of real-time voice signals transmitted by 4 of the miniature audio nodes.

[0038] The central control module is used to send remote control commands to each of the miniature audio nodes, and to merge and store the received multi-node recording files after time synchronization to the storage module.

[0039] Example

[0040] This embodiment provides a distributed reconnaissance tool, including 16 miniature audio nodes and 1 base station unit.

[0041] Miniature audio node parameter configuration

[0042] The microphone module uses a non-porous vibration microphone with a sensitivity of -40dB.

[0043] Recording module: 32G Class 10 SD card, sampling rate 16kHz, bit rate 64kbps, supports continuous recording for 60 days;

[0044] Encryption module: AES-128 encryption algorithm;

[0045] First wireless transmission module: operating frequency 433MHz (dedicated frequency below 1GHz), transmission rate 256kbps, communication distance 500m (open environment);

[0046] Battery: 3.7V / 2000mAh lithium polymer battery, standby time 30 days, working time 15 days;

[0047] Waterproof rating: IP65.

[0048] Base station unit parameter configuration

[0049] Second wireless transmission module: supports orthogonal graph division multiple access technology, with a maximum of 32 access nodes, 4 simultaneous real-time transmission channels, and a receiving sensitivity of -110dBm;

[0050] Speech enhancement module: Implements spectral subtraction algorithm based on DSP chip, with processing latency ≤100ms;

[0051] Network communication module: WIFI supports 802.11b / g / n, Ethernet supports 10 / 100Mbps;

[0052] Storage module: 1TB SSD hard drive;

[0053] Central control module: Uses an ARM Cortex-A9 processor with a main frequency of 1.2GHz.

[0054] Work process verification

[0055] Sixteen miniature audio nodes were deployed in a 100m x 100m outdoor area, with the base station unit positioned at the center of the area. After pairing was completed using orthogonal graph multiple access (OMA) technology, real-time monitoring was initiated.

[0056] Multi-node access: The base station successfully connected to 16 nodes with no signal interference and a bit error rate of ≤10%. -5 ;

[0057] Real-time transmission: Simultaneously transmits 4 audio signals with a delay of ≤200ms and a noise suppression ratio of ≥20dB after spectral subtraction processing;

[0058] Time synchronization: When a mobile target passes through the coverage area of ​​5 nodes in sequence, the base station will synchronize and merge the recording files of the 5 nodes, and the voice will be continuous without interruption.

[0059] Data security: The encrypted audio files passed brute-force attacks and were not leaked;

[0060] Deployment and maintenance: The battery charging station can fully charge 8 batteries in 2 hours, and the node can download the recording files of 16 nodes in 30 minutes by connecting to the station.

[0061] The above embodiments demonstrate that the distributed reconnaissance tool of the present invention can stably achieve multi-node access, high-quality voice monitoring, and efficient maintenance, meeting the needs of actual combat.

[0062] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A distributed reconnaissance tool, characterized in that, The system comprises a plurality of micro audio nodes and a base unit, and the micro audio nodes are wirelessly connected with the base unit; The micro audio node comprises, in sequence, a sound pickup module, a voice processing module, a recording module, an encryption module and a first wireless transmission module, and further comprises a low-power battery for supplying power to the modules, and the micro audio node is externally provided with a waterproof shell; The base unit comprises a second wireless transmission module, a central control module, a voice enhancement module, a network communication module and a storage module, and the second wireless transmission module, the voice enhancement module, the network communication module and the storage module are electrically connected with the central control module; The second wireless transmission module adopts an orthogonal graph multiple access technology to realize communication connection with a maximum of 32 micro audio nodes and support simultaneous reception of real-time voice signals transmitted by 4 micro audio nodes. The central control module is used to send remote control commands to the micro audio nodes and to store the received multi-node recording files after time synchronization.

2. The distributed reconnaissance tool of claim 1, wherein, The orthogonal graph multiple access technology is realized based on a frequency hopping graph, and the second wireless transmission module and the first wireless transmission module control carrier frequency hopping through a preset pseudo-random code, and the carrier frequency is a special digital frequency point lower than 1 GHz.

3. The distributed reconnaissance tool of claim 1, wherein, The voice enhancement module adopts a spectral subtraction algorithm, and the implementation process of the spectral subtraction algorithm comprises: performing FFT transformation on the received noise-affected voice signal, converting to the frequency domain and retaining phase information; obtaining noise spectrum estimation through a signal initial "silent section"; subtracting the noise spectrum estimation from the voice signal spectrum in the frequency domain to obtain an enhanced voice power spectrum; performing IFFT transformation combined with the retained phase information to convert back to the time domain and output an enhanced voice signal.

4. The distributed reconnaissance tool of claim 1, wherein, The encryption module adopts an AES encryption algorithm to encrypt the recording files stored by the recording module and the voice data transmitted by the first wireless transmission module.

5. The distributed reconnaissance tool of claim 1, wherein, The recording module of the micro audio node adopts a 32G SD card as a storage medium, supports a maximum recording time of 2 months, and is further adapted with a battery charging dock station and a node connection dock station, the battery charging dock station supports simultaneous charging of 8 batteries, and the node connection dock station supports simultaneous downloading of recording files by 16 nodes.

6. The distributed reconnaissance tool of claim 1, wherein, The network communication module simultaneously supports WIFI and Ethernet connections, is used to realize communication between the base unit and external computers and mobile phones, and is used for external devices to receive real-time voice signals, download recording files and remotely control system operation.

7. The distributed reconnaissance tool of claim 1, wherein, The sound pickup module of the micro audio node is a high-sensitivity non-hole vibration pickup microphone.

8. The distributed reconnaissance tool of claim 1, wherein, The communication link between the first wireless transmission module and the second wireless transmission module is a bidirectional link, which can simultaneously transmit digital voice signals and remote control commands.

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