Explosion-proof wireless 4G / 5G base station for underground coal mining

Abstract

The invention relates to the technical field of wireless communication and underground coal mine safety, and discloses an explosion-proof wireless 4G / 5G base station for underground coal mining, which comprises a communication module integrated with a 4G / 5G communication protocol and supporting wireless signal transmission; the antenna array comprises a multi-band antenna capable of adjusting the direction; the intelligent reflecting surface module is deployed in a roadway and is used for dynamically optimizing an electromagnetic wave propagation path; the distributed MIMO system comprises a plurality of distributed antenna units and a centralized control unit. And the ultra-reliable low-delay communication module supports a 5G network slicing technology. According to the invention, a signal path is dynamically optimized through the intelligent reflecting surface, and cooperative transmission with millimeter wave-distributed MIMO is realized, so that the signal coverage quality and the high-capacity data transmission capability in an underground complex environment are remarkably improved; and meanwhile, based on a 5GURLLC protocol, edge computing and a wireless charging technology, ultra-low time delay and high reliability of a key task are guaranteed, and long-term endurance and intelligent maintenance of equipment are realized.

Description

Technical Field

[0001] The present invention relates to the technical fields of wireless communication and underground coal mine safety, and specifically provides an explosion-proof wireless 4G / 5G base station for underground coal mine excavation. Background Art

[0002] In the underground coal mine operation environment, a reliable and efficient communication system is the core foundation for ensuring safe production and intelligent transformation. However, traditional underground communication technologies are limited by complex geological structures and harsh environmental conditions, and generally suffer from problems such as insufficient signal coverage, limited transmission capacity, poor real-time performance, and difficult equipment maintenance.

[0003] Existing wireless communication systems mostly use low-frequency band signals or single base station deployments, which are difficult to adapt to the multipath attenuation and long-distance bend characteristics of mine roadways, resulting in frequent signal blind spots and significant fluctuations in communication quality. Especially in areas with dense equipment, traditional systems cannot meet the high-traffic service requirements such as high-definition video monitoring and real-time environmental monitoring due to limited bandwidth, seriously restricting the process of coal mine automation and informatization. In addition, existing base station equipment relies on wired power supply and regular maintenance, posing safety hazards and high operation and maintenance costs in explosive environments. Although some technologies attempt to improve communication effects through relay nodes or anti-interference designs, they lack the adaptive ability to the dynamic environment of roadways and are difficult to systematically solve the contradictions among signal attenuation, delay, and reliability. Therefore, there is an urgent need for an explosion-proof wireless communication solution that integrates intelligent signal optimization, high-bandwidth transmission, low-latency guarantee, and long-term power supply to break through the multiple constraints of the complex underground environment on the communication system. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention provides an explosion-proof wireless 4G / 5G base station for underground coal mine excavation, which solves the problems of insufficient wireless signal coverage, limited bandwidth, high communication delay, and poor equipment battery life in the complex underground environment of the existing technology.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: An explosion-proof wireless 4G / 5G base station for underground coal mine excavation, comprising: A communication module, integrating 4G / 5G communication protocols and supporting wireless signal transmission; An antenna array, including multi-band antennas with adjustable directions; An intelligent reflecting surface module, deployed in the roadway for dynamically optimizing the electromagnetic wave propagation path; A distributed MIMO system, including multiple distributed antenna units and a centralized control unit; A ultra-reliable low-latency communication module, supporting 5G network slicing technology; A wireless charging module, used to provide non-contact power supply for the base station and associated devices.

[0006] Preferably, the intelligent reflecting surface module includes: An adjustable reflector array configured to dynamically adjust the reflection angle; A signal analysis unit that monitors signal attenuation and multipath effects in real time through AI algorithms; A reflection parameter adjustment unit that automatically optimizes the reflection path according to environmental data.

[0007] Preferably, the communication module supports the millimeter wave band and realizes bandwidth optimization in the mine roadway through ultra-dense cell deployment.

[0008] Preferably, the antenna unit of the distributed MIMO system adopts beamforming technology and dynamically adjusts the power distribution and signal coverage range of each antenna through AI algorithms.

[0009] Preferably, the URLLC module provides a dedicated low-latency channel for underground safety monitoring and personnel positioning tasks through 5G network slicing technology, with an end-to-end latency of less than 10 ms.

[0010] Preferably, the wireless charging module is based on the principle of electromagnetic induction, realizes non-contact energy transmission inside and outside the flameproof enclosure, and supports simultaneous charging of multiple devices.

[0011] Preferably, the wireless charging module is linked with the intelligent battery management system to monitor the battery health status in real time and optimize the charging and discharging strategies.

[0012] Preferably, the AI algorithm of the intelligent reflecting surface module includes a deep learning model, which is trained through the historical communication data and environmental parameters of the mine roadway to realize predictive adjustment of the reflection path.

[0013] Preferably, the flameproof enclosure is made of carbon fiber composite material with embedded heat dissipation fins.

[0014] Preferably, the communication module integrates an edge computing unit for local processing of real-time monitoring data and realizes low-latency synchronization of data with the cloud server through 5G URLLC technology.

[0015] The present invention provides a flameproof wireless 4G / 5G base station for underground coal mining, having the following beneficial effects: 1. The present invention dynamically optimizes the electromagnetic wave propagation path through the intelligent reflecting surface, combined with the multi-node cooperative transmission of the distributed MIMO system, effectively overcoming the problems of multipath effects, signal attenuation, and blind spots in the coal mine roadway. The RIS real-time senses environmental changes and adjusts the reflection direction to ensure continuous signal coverage in non-line-of-sight areas; the distributed MIMO enhances the signal strength through space diversity and beamforming, providing a stable and reliable communication link for underground equipment.

[0016] 2. Based on millimeter - wave frequency bands and ultra - dense cell deployments, the present invention supports high - speed transmission of high - frequency signals, meeting the high - traffic service requirements of video surveillance, sensor networks, etc. The co - design of millimeter - wave communication and distributed MIMO expands the equivalent channel capacity through carrier aggregation and spatial multiplexing technologies, solving the problem of insufficient bandwidth in traditional systems and providing data support for coal mine intelligentization.

[0017] 3. The present invention integrates the 5G URLLC protocol and edge computing units. Through physical layer frame structure optimization, network slicing, and localized data processing, it achieves micro - second - level responses for key tasks such as security monitoring and equipment control. Network slicing isolates high - priority services, edge computing reduces dependence on the cloud, and redundant transmission and fault - tolerance mechanisms ensure communication continuity in extreme environments, significantly improving the safety and efficiency of underground operations.

[0018] 4. The present invention combines a wireless charging module with an intelligent battery management system (BMS). Through non - contact energy transfer and dynamic charge - discharge strategies, it realizes automatic power supply for base stations and associated devices. The explosion - proof design and multi - device collaborative charging mechanism reduce the need for cable laying. The BMS monitors the battery health status in real - time, optimizes the service life, and reduces the maintenance frequency and manual intervention cost of underground equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the system architecture diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] Please refer to the attached Figure 1 , an explosion - proof wireless 4G / 5G base station for underground coal mine excavation provided by an embodiment of the present invention includes: A communication module, integrating 4G / 5G communication protocols and supporting wireless signal transmission; In this embodiment, the communication module is the core functional unit of the explosion - proof wireless 4G / 5G base station, used to achieve high - speed, stable, and low - latency wireless communication in the complex environment of underground coal mines. The communication module integrates a multi - band antenna array, an intelligent reflecting surface collaborative control unit, a millimeter - wave transceiver unit, a distributed MIMO system, and a 5G URLLC protocol stack, and solves signal attenuation, bandwidth limitation, and real - time requirements in underground roadways through multi - technology integration. The following is the detailed technical solution of the communication module: In this embodiment, the antenna array of the communication module includes multiple groups of independently adjustable directional antennas, supporting hybrid coverage of the low-frequency band (700 MHz - 3.5 GHz) and the high-frequency millimeter-wave band (e.g., 26 GHz or 28 GHz). Preferably, the low-frequency band antennas are used for wide-area coverage, while the high-frequency millimeter-wave antennas are deployed in high-density communication areas in the roadway. The antenna array is linked with the intelligent reflecting surface (RIS) module through optical fiber or wireless links to receive the electromagnetic environment data feedback by the RIS in real time.

[0022] The intelligent reflecting surface module is composed of multiple adjustable electromagnetic units, and each unit realizes the dynamic adjustment of the reflection angle based on microelectromechanical system (MEMS) or liquid crystal metasurface technology. The communication module is built-in with a signal analysis algorithm, which models the signal strength distribution in the roadway through a convolutional neural network (CNN) to generate the reflecting surface adjustment instructions. For example, when multipath interference is detected in a certain area, the algorithm controls the RIS unit to adjust the reflection path to the optimal path of non-line-of-sight (NLoS) propagation to avoid signal attenuation.

[0023] In this embodiment, the millimeter-wave transceiver unit of the communication module supports high-frequency band signal transmission, and the preferred frequency bands are 26 GHz or 28 GHz. The millimeter-wave antennas adopt a phased array design and dynamically adjust the signal coverage direction through beamforming technology. To achieve continuous coverage of the mine roadway, the communication module adopts an ultra-dense small cell deployment strategy, that is, small-sized millimeter-wave base stations are deployed at set intervals.

[0024] The spectrum resources are allocated between adjacent base stations through orthogonal frequency division multiplexing (OFDM) technology to avoid co-channel interference. Preferably, the time division duplex (TDD) mode is adopted between the base stations, and the uplink and downlink resources are dynamically allocated according to the real-time traffic demand. After being reflected by the RIS, the millimeter-wave signal can penetrate some non-metallic obstacles (such as plastic pipes) and improve the signal-to-noise ratio at the receiving end through multipath enhancement technology.

[0025] In this embodiment, the distributed MIMO system of the communication module is composed of multiple distributed antenna units (DUs) and a central control unit (CUs). The DUs are deployed on the top or side wall of the roadway, and each DU includes at least 4 groups of MIMO antennas, supporting spatial multiplexing and diversity transmission. The CUs schedule the transmit power and beam direction of each DU through coordinated multi-point transmission (CoMP) technology.

[0026] The dynamic beamforming algorithm optimizes the antenna weights in real time based on the channel state information (CSI). Preferably, the minimum mean square error (MMSE) algorithm is used to calculate the beamforming matrix to suppress multi-user interference. For example, when the terminal device moves to the intersection of the roadway, the CUs schedule 3 adjacent DUs to send the same data stream simultaneously, and improve the reception reliability through spatial diversity. In addition, the MIMO system supports the carrier aggregation technology, which binds the low-frequency band and the millimeter-wave band to expand the channel capacity.

[0027] In this embodiment, the URLLC function of the communication module is implemented based on the 5G new radio (NR) protocol, and the physical layer frame structure adopts a flexible time slot configuration, supporting a microsecond-level scheduling period. To achieve ultra-low latency, the communication module integrates an edge computing unit to locally process key data (such as gas concentration, personnel positioning information) to avoid remote transmission delays.

[0028] The network slicing technology divides the communication resources into independent logical channels, including the security monitoring slice, the video transmission slice, and the device control slice. Preferably, the security monitoring slice adopts the grant-free access mode, and the terminal device can directly upload data without applying for resources when detecting an emergency. The slices are isolated by a software-defined network (SDN) controller to ensure the bandwidth and latency guarantee of high-priority services.

[0029] In this embodiment, the cooperative control of the communication module and the intelligent reflecting surface (RIS) is achieved through a closed-loop feedback mechanism. The communication module periodically sends pilot signals to the RIS. After receiving the signals, the RIS measures the signal strength, phase, and multipath distribution, and feeds the data back to the AI analysis unit of the communication module.

[0030] The AI analysis unit predicts the electromagnetic environment changes in the future time slots based on the long short-term memory (LSTM) model and generates the reflecting surface adjustment instructions. For example, when it is predicted that there will be signal occlusion caused by device movement in a certain area, the RIS reflection path is adjusted in advance to establish a redundant communication link. Preferably, the RIS control instructions are transmitted through a dedicated control channel and isolated from the data channel to avoid interference.

[0031] In this embodiment, the communication module uses adaptive filtering technology to suppress electromagnetic interference in the underground environment. The receiving end is configured with a multi-stage band-pass filter, and the filtering parameters are dynamically adjusted according to the real-time spectrum analysis results. For impulse interference (such as the transient noise generated by the start and stop of mining equipment), the communication module starts the frequency hopping spread spectrum (FHSS) mode and quickly switches between multiple sub-bands.

[0032] In terms of the fault tolerance mechanism, when a certain distributed antenna unit (DUs) fails, the central control unit (CUs) automatically enables the standby antenna and ensures the continuity of data transmission through the redundant routing protocol. Preferably, critical data streams adopt multi-path transmission, and the reliability is improved through forward error correction (FEC) coding and redundant packet retransmission.

[0033] In this embodiment, the hardware of the communication module is integrated in the explosion-proof housing, and the main control chip uses a multi-core processor, which is responsible for signal processing, AI algorithm operation, and protocol stack management respectively. During the power-on initialization phase, the communication module automatically scans the available frequency bands and selects the optimal coverage scheme according to the pre-set mine map.

[0034] During the normal operation phase, the communication module collects environmental data in real time (such as temperature, humidity, and equipment location), and dynamically optimizes the following parameters in combination with the AI model: millimeter wave beam pointing, RIS reflection path, MIMO antenna weight, and network slice resource allocation. Preferably, the optimization instructions are distributed to each sub-module through the control bus to ensure the system response speed.

[0035] Antenna array, including multi-band antennas with adjustable directions; In this embodiment, the antenna array is a core component of the explosion-proof wireless 4G / 5G base station, which is used to achieve multi-band signal coverage, dynamic beamforming, and anti-interference transmission in the complex roadway environment of underground coal mines. The antenna array solves the problems of signal attenuation, coverage blind spots, and insufficient capacity existing in traditional underground communication systems through multi-band hybrid design, intelligent reflecting surface collaborative control, and distributed MIMO architecture. The following is the detailed technical solution of the antenna array: In this embodiment, the antenna array is composed of a low-frequency antenna unit and a high-frequency millimeter wave antenna unit in combination. The low-frequency antenna unit preferably adopts a broadband dipole or microstrip antenna structure, and its operating frequency band covers 700 MHz to 3.5 GHz, which is used to achieve wide-area signal coverage in the mine roadway. The high-frequency millimeter wave antenna unit preferably adopts a phased array design, supports the 26 GHz or 28 GHz frequency band, and is deployed in high-density communication areas in the mine (such as the excavation operation face and the equipment concentration area), and improves the communication capacity of the local area through the narrow beam and high gain characteristics.

[0036] The layout of the antenna array is optimized based on the three-dimensional model of the mine roadway. Preferably, a longitudinal staggered arrangement method is adopted, the interval of the low-frequency antennas is set to half-wavelength distance, and the millimeter wave antennas are arranged in a dense array form. The antenna units are connected to the internal circuit of the explosion-proof housing through flexible substrates to ensure stable electrical performance in the mine vibration environment.

[0037] In this embodiment, the antenna array and the reconfigurable intelligent surface (RIS) module cooperate through a closed-loop feedback mechanism. The antenna array periodically transmits pilot signals. After receiving the signals, the RIS module analyzes the multipath distribution and attenuation characteristics of the signals and feeds the data back to the signal processing unit of the base station.

[0038] Based on a preset convolutional neural network (CNN) model, the signal processing unit models the electromagnetic environment of the roadway and generates a phase adjustment matrix for the RIS reflection units. Preferably, the phase adjustment matrix is dynamically calculated by the following formula: ; where is the channel response of the direct path, is the channel response of the RIS reflection path, is the phase parameter of the reflection unit. Through an iterative optimization algorithm, the RIS reflection path is adjusted in real time to focus the signal energy on the target area.

[0039] In this embodiment, the beamforming function of the antenna array is implemented through a digital and analog hybrid architecture. The digital beamforming unit performs weighted synthesis on multiple antenna signals based on a baseband processor; the analog beamforming unit adjusts the phase and amplitude of the radio frequency signal through phase shifters and attenuators.

[0040] Preferably, the beamforming weight matrix is calculated using the minimum mean square error (MMSE) algorithm to suppress multi-user interference. For the th user, its beamforming weight ... is solved by the following formula: ; where is the channel vector of user and is the noise power. Dynamic beamforming enables the antenna array to adjust the beam direction and coverage range in real time according to the terminal position and movement trajectory.

[0041] Distributed MIMO Architecture and Spatial Diversity Transmission In this embodiment, the antenna array improves the system capacity and coverage reliability through a distributed MIMO architecture. Multiple distributed antenna units (DUs) are deployed on the top and side walls of the roadway. Each DU contains at least 4 groups of MIMO antennas, supporting spatial diversity and multiplexing transmission.

[0042] Centralized control units (CUs) connect to each DU via optical fiber links and schedule antenna resources based on real-time channel state information (CSI). Optimally, when a terminal device is at a lane intersection or in an obstructed area, the CUs schedule three adjacent DUs to simultaneously transmit the same data stream, leveraging spatial diversity to improve the received signal-to-noise ratio. Furthermore, the MIMO system supports carrier aggregation, combining low-frequency bands with millimeter-wave bands to expand the equivalent channel bandwidth.

[0043] In this embodiment, the antenna array is specifically optimized for the complex electromagnetic interference environment underground. The receiving end is equipped with a multi-stage tunable bandpass filter, whose bandwidth and center frequency are dynamically adjusted based on real-time spectrum sensing results. To address pulsed interference (such as transient noise generated by the start-up and shutdown of mining equipment), the antenna array activates frequency-hopping spread spectrum (FHSS) mode, rapidly switching between multiple pre-set sub-bands.

[0044] In terms of fault tolerance, when a distributed antenna unit (DU) fails due to a fault or obstruction, the centralized control unit (CU) automatically activates a redundant antenna unit and ensures continuous data transmission through a multipath routing protocol. Forward error correction (FEC) encoding and redundant packet retransmission strategies are preferably used for critical data streams, combined with antenna diversity reception to improve transmission reliability.

[0045] In this embodiment, the antenna array's physical structure adopts a modular design, with antenna units for each frequency band independently packaged and connected to the base station's main control board via plug-in interfaces. The antenna array also incorporates built-in environmental sensors that monitor temperature, humidity, and vibration in real time, feeding feedback to the control unit to trigger adaptive adjustments.

[0046] Preferably, the adaptive adjustment includes the following scenarios: Tunnel structure changes: When tunnel collapse or equipment movement is detected, the millimeter wave beam direction is automatically adjusted to avoid obstacles; Multi-user load fluctuations: Dynamically switch MIMO modes (diversity / multiplexing) based on the number of access terminals to optimize resource allocation; Interference source appears: When a strong interference signal is identified, switch to anti-interference mode and adjust the filter parameters.

[0047] Intelligent reflective surface modules, deployed in the roadway, are used to dynamically optimize the electromagnetic wave propagation path; In this embodiment, the Reconfigurable Intelligent Surface (RIS) module is a key component of a flameproof wireless 4G / 5G base station. It is used to dynamically optimize electromagnetic wave propagation paths in underground coal mine tunnels, overcoming multipath effects and signal attenuation. Through the coordinated operation of an adjustable reflector array, an environmental sensing unit, and an intelligent control algorithm, the module achieves signal enhancement and coverage expansion in non-line-of-sight (NLoS) scenarios. The following is a detailed technical solution for the intelligent reflector module: In this embodiment, the intelligent reflective surface module is composed of multiple independently controllable reflective units, each preferably utilizing a liquid crystal metasurface or microelectromechanical system (MEMS) drive structure. The surface of each reflective unit is coated with a periodically arranged metal resonant structure. By changing the arrangement of liquid crystal molecules or the deflection angle of the MEMS cantilever, the unit's reflection phase and amplitude of the incident electromagnetic wave are dynamically adjusted.

[0048] The reflective elements are preferably arranged in a rectangular or hexagonal array to maximize the reflective surface's wavefront control capabilities. The entire reflective surface is enclosed in a flameproof enclosure, preferably constructed of impact-resistant polycarbonate composite material and filled with inert gas to ensure stable operation in explosive underground environments. The reflective surface is connected to the base station communication module via optical fiber or a wireless control link, and the explosion-proof joint design of the enclosure complies with GB3836.2 standards.

[0049] In this embodiment, the dynamic adjustment function of the intelligent reflector module is achieved through closed-loop feedback control. The reflector has a built-in signal acquisition unit that receives pilot signals from the base station communication module in real time and measures the signal's multipath component strength, delay spread, and angle of arrival (AoA). Furthermore, the reflector integrates environmental sensors to collect data on temperature, humidity, and obstacle locations within the roadway.

[0050] The adjustment instructions for the reflection parameters (phase, amplitude) are generated by the AI analysis module of the base station. Preferably, the AI analysis module uses a convolutional neural network (CNN) to train historical signal data and environmental parameters to establish a tunnel electromagnetic propagation model. When the signal strength in a certain area is detected to be lower than the threshold, the AI module generates a phase adjustment matrix using the following formula: ; in, is the direct path channel response, is the channel response of the RIS reflection path, is the phase parameter of the reflection unit. It is iteratively optimized by gradient descent algorithm , to maximize the composite signal strength.

[0051] In this embodiment, the cooperative control of the intelligent reflecting surface module and the base station communication module is achieved through periodic signaling interaction. The base station periodically transmits pilot signals. After receiving the signals, the reflecting surface extracts the channel state information (CSI) and feeds back the CSI data to the signal processing unit of the base station through the control link.

[0052] The signal processing unit generates adjustment instructions for the reflecting elements according to the CSI data and the prediction results of the AI model. Preferably, the adjustment instructions include the phase offset and amplitude attenuation coefficient of each reflecting element. The instructions are transmitted to the reflecting surface through the orthogonal frequency division multiplexing (OFDM) control channel and isolated from the data channel to avoid interference. After parsing the instructions, the reflecting surface control unit drives the MEMS or liquid crystal unit to complete the parameter adjustment and form a directional reflection beam. For example, when the terminal device moves to the corner of the roadway, the reflecting surface deflects the incident beam to the corner area to establish an indirect communication link.

[0053] In this embodiment, the intelligent reflecting surface module has the ability to adapt to environmental changes. When a change in the roadway structure (such as equipment movement, cave-in) or a sudden interference is detected, the reflecting surface control unit starts a dynamic reconfiguration process. Preferably, the reconfiguration process includes the following steps: Obtain updated data on the three-dimensional structure of the roadway through lidar or a camera; Modify the electromagnetic propagation model in combination with the updated data; Recalculate the adjustment matrix for the reflecting elements and issue instructions.

[0054] To cope with the local failure of the reflecting elements (such as dust coverage or mechanical damage), the module has a built-in redundant reflection path design. When a certain reflecting element fails, the control unit automatically bypasses the element and schedules adjacent elements to compensate for the reflection function. Preferably, the compensation algorithm fine-tunes the beam direction through the phase superposition of adjacent elements to ensure the continuity of the reflection path.

[0055] In this embodiment, the intelligent reflecting surface module is connected to the main control unit of the base station through an optical fiber or an intrinsically safe wireless link. The reflecting surface has an independent power supply module, preferably an intrinsically safe lithium battery pack, and realizes non-contact energy replenishment through a wireless charging module. The power supply circuit design of the module meets the requirements of the "Coal Mine Safety Regulations". The charging and discharging process is monitored by an intelligent battery management system (BMS) to prevent overvoltage or overcurrent risks.

[0056] The distributed MIMO system includes multiple distributed antenna units and a centralized control unit; In this embodiment, the distributed MIMO system is the core functional architecture of an explosion-proof wireless 4G / 5G base station, which is used to improve the communication capacity, coverage range, and transmission reliability in underground coal mine roadways. The system solves the problems of signal attenuation, interference, and capacity limitation existing in traditional centralized MIMO systems in complex roadway environments through multi-node distributed antenna deployment, cooperative beamforming, and dynamic resource scheduling. The following is the detailed technical solution of the distributed MIMO system: In this embodiment, the distributed MIMO system consists of multiple distributed antenna units (DUs) and a centralized control unit (CU). The DUs are preferably deployed near the top of the roadway, the sidewall, or key equipment. Each DU contains multiple groups of MIMO antennas and supports a hybrid operating mode in low-frequency bands (such as 2.6 GHz and 3.5 GHz) and high-frequency millimeter-wave bands (such as 26 GHz or 28 GHz).

[0057] The DUs are connected to the CU through optical fibers or intrinsically safe wireless links. The CU is responsible for the collection of global channel state information (CSI) and resource scheduling. The antenna array of the DUs adopts a broadband design, preferably a dual-polarized microstrip antenna or a phased array structure, to adapt to the irregular spatial characteristics of the mine roadway. Each DU is built with an independent radio frequency front-end and baseband processing module, supporting local signal preprocessing and real-time data interaction with the CU.

[0058] In this embodiment, the beamforming function of the distributed MIMO system is realized through the cooperative calculation of the CU and the DUs. Based on the global CSI data, the CU generates the beamforming weight matrix of each DU through the minimum mean square error (MMSE) algorithm or the zero-forcing (Zero-Forcing) algorithm.

[0059] Preferably, the user priority weight is introduced into the calculation process of the weight matrix to ensure the communication quality of high-priority services (such as safety monitoring).

[0060] In this embodiment, the distributed MIMO system improves signal reliability through coordinated multi-point transmission (CoMP) technology. When the terminal device is at a roadway intersection or in a signal occlusion area, the CU schedules multiple adjacent DUs to send the same data stream to the terminal simultaneously, using spatial diversity gain to resist multipath fading. The receiver synthesizes multiple paths of signals through the maximum ratio combining (MRC) or equal gain combining (EGC) algorithm. In addition, the system supports the spatial multiplexing mode, and the data stream is split into multiple independent sub-streams through precoding technology and sent by different DUs respectively to improve the channel capacity.

[0061] In this embodiment, the distributed MIMO system optimizes the spectrum utilization rate through dynamic channel allocation technology. The CU monitors the interference level and load status of each frequency band in real time and preferentially allocates idle channels to high-priority services. Preferably, the orthogonal frequency division multiple access (OFDMA) technology is used to divide the spectrum into multiple subcarriers, and the subcarrier resources are dynamically allocated according to the channel quality indicator (CQI) of the terminal device.

[0062] To expand the system capacity, the MIMO system supports carrier aggregation of low-frequency bands and millimeter-wave bands. The CU combines the channels of different frequency bands into a logical channel through frequency band binding technology, and its equivalent bandwidth is: ; where and are the available bandwidths of the low-frequency band and the millimeter-wave band respectively.

[0063] In this embodiment, the distributed MIMO system is specifically optimized for the downhole electromagnetic interference environment. The receiving end is configured with an adaptive interference suppression filter, and the filtering coefficient is dynamically adjusted through the least mean square (LMS) algorithm to suppress narrowband interference and co-frequency interference. For impulse noise interference, the system starts the frequency hopping spread spectrum (FHSS) mode and quickly switches between multiple preset frequency points.

[0064] In terms of the fault tolerance mechanism, when a certain DU fails due to a fault or environmental occlusion, the CU automatically enables the standby DU to take over the coverage task and ensures the continuity of data transmission through the redundant routing protocol. Preferably, the key data stream adopts the forward error correction (FEC) coding and multi-copy transmission strategy, and combines the spatial diversity reception of the DUs to improve the transmission reliability.

[0065] In this embodiment, the hardware of the distributed MIMO system is integrated in the explosion-proof housing, and the DUs and the CU are connected through optical fibers or intrinsically safe wireless links. During the system initialization phase, the CU scans the roadway environment through pilot signals to construct an initial channel state database.

[0066] During the operation phase, the CU periodically executes the following processes: Collect the CSI data reported by each DU and the location information of the terminal device; Predict the channel change trend through the AI algorithm, and update the beamforming weight and resource allocation strategy; Send control instructions to each DU to adjust the transmission power, beam direction, and operating frequency band; Monitor the system status and trigger the fault tolerance mechanism or interference suppression mode.

[0067] The ultra-reliable low-latency communication module supports 5G network slicing technology; In this embodiment, the Ultra-Reliable Low-Latency Communication (URLLC) module is a key functional unit of an explosion-proof wireless 4G / 5G base station, which is used to meet the high real-time and high reliability requirements of key tasks such as safety monitoring, equipment control, and personnel positioning in the underground coal mine environment. The module is optimized based on the 5G New Radio (NR) protocol, and combines network slicing technology, edge computing units, and innovative physical layer frame structures to achieve microsecond-level latency and transmission reliability of over 99.999%. The following is the detailed technical solution of the URLLC module: In this embodiment, the physical layer frame structure of the URLLC module adopts flexible time slot configuration and Mini-Slot design. Preferably, the length of a single micro-slot is shortened to 2-7 OFDM symbols, supporting dynamic time slot aggregation and segmentation. For underground emergency events (such as excessive gas concentration), the module enables a Grant-Free access mechanism, and the terminal device can directly send data without waiting for uplink resource allocation.

[0068] The scheduling algorithm is optimized based on the Hybrid Automatic Repeat reQuest (HARQ) mechanism, and the retransmission efficiency is improved through predefined Redundancy Version (RV) and Incremental Redundancy (IR) strategies.

[0069] In this embodiment, the URLLC module divides communication resources into independent logical slices through Software-Defined Network (SDN) technology, including safety monitoring slices, video transmission slices, and equipment control slices. The safety monitoring slice preferably exclusively occupies high-frequency band resources (such as millimeter wave bands) and configures the highest priority queue to ensure its real-time performance.

[0070] In this embodiment, the URLLC module integrates an edge computing unit, which is deployed inside the base station or adjacent roadway nodes, and is used for local processing of key data. The edge computing unit preferably adopts a heterogeneous computing architecture, including a CPU, a GPU, and a dedicated AI acceleration chip, supporting real-time data filtering, compression, and event recognition.

[0071] For example, when the gas sensor detects abnormal concentration, the edge unit directly triggers an alarm command and controls the ventilation equipment without uploading the data to the cloud. The data processing flow is optimized through a pipeline architecture, and data acquisition, feature extraction, and decision generation are executed in parallel.

[0072] In this embodiment, the URLLC module improves reliability through multi-path redundant transmission. The key data stream is simultaneously sent via the low-frequency band and the millimeter wave band, and the receiving end uses the Selective Combining (SC) or Maximum Ratio Combining (MRC) algorithm to synthesize multiple paths of signals. The scheduling strategy of the redundant path is dynamically selected based on the link quality In this embodiment, the URLLC module works in cooperation with the distributed MIMO system and the intelligent reflecting surface (RIS) module. When the quality of a certain communication link deteriorates, the URLLC module triggers the following cooperation process: Dynamically adjust the reflection path through the RIS to establish redundant communication links; Schedule adjacent distributed antenna units (DUs) to participate in data transmission; Switch to a modulation and coding scheme with stronger anti-interference ability (such as QPSK instead of 64QAM).

[0073] In terms of the fault tolerance mechanism, the module is built-in with a heartbeat detection and fast switching protocol. When the main link is interrupted, the backup link takes over the communication task within milliseconds.

[0074] A wireless charging module for providing non-contact power supply to the base station and associated devices; In this embodiment, the wireless charging module is an important part of the explosion-proof wireless 4G / 5G base station, which is used to solve the problems of insufficient battery life and frequent maintenance of equipment in the underground coal mine environment. Based on the principle of electromagnetic induction, combined with intelligent energy management and explosion-proof safety design, the module realizes non-contact energy transmission to ensure the long-term stable operation of the base station and associated devices in complex environments. The following is the detailed technical solution of the wireless charging module: In this embodiment, the wireless charging module consists of a transmitter and a receiver. The transmitter is integrated on the inner wall of the explosion-proof housing or independently deployed at a fixed position in the mine. Preferably, a planar spiral coil design is adopted, and the coil material is multi-strand litz wire to reduce high-frequency skin effect loss. The receiver is embedded inside the base station device, and the coil structure matches that of the transmitter, and energy transmission is realized through magnetic resonance coupling.

[0075] The energy transmission process is based on the principle of electromagnetic induction. The transmitter converts direct current into an alternating current signal through a high-frequency inverter circuit, and drives the transmitting coil to generate an alternating magnetic field. The receiving coil induces the magnetic field and converts it into electrical energy, which charges the device battery after passing through the rectifier and filter circuit. Preferably, the system operating frequency is selected as the 6.78 MHz ISM band to avoid interference with other communication bands.

[0076] In this embodiment, the wireless charging module is linked with the intelligent battery management system (BMS) to monitor the battery status in real time and optimize the charging strategy. The BMS collects battery voltage, temperature, state of health (SOH), and state of charge (SOC) data through high-precision sensors, and dynamically adjusts the charging current and voltage based on these parameters.

[0077] Preferably, the charging process is divided into two stages: constant current (CC) and constant voltage (CV). In the constant current stage, it is quickly charged to the set threshold with the maximum safe current. In the constant voltage stage, the current is gradually reduced to avoid overcharging.

[0078] In this embodiment, the wireless charging module supports simultaneous charging of multiple devices. The transmitting end adopts a multi-coil array design, and each coil can be independently controlled. Energy is allocated to different devices through frequency-division multiplexing (FDM) or time-division multiplexing (TDM) technology. The receiving end is built with an identity recognition unit, which interacts with the transmitting end through near-field communication (NFC) or Bluetooth to exchange device information and achieve priority scheduling.

[0079] Preferably, high-priority devices (such as the base station main control unit) are given priority in energy allocation, and low-priority devices (such as sensor nodes) are charged during idle periods.

[0080] In this embodiment, the hardware design of the wireless charging module meets the explosion-proof requirements in coal mines. The coils at the transmitting and receiving ends are both encapsulated in flameproof enclosures. The enclosure material is preferably impact-resistant modified plastic or aluminum alloy, filled with inert gas inside, and the circuit module is solidified with potting glue to prevent explosion caused by electric arcs or sparks.

[0081] The design of the flameproof joint surface complies with the GB3836.2 standard, and the width and clearance of the joint surface meet the requirements for explosion pressure release. The circuit protection measures of the charging module include overvoltage protection, overcurrent protection, and short-circuit protection. Key components (such as power MOS transistors and resonant capacitors) use industrial-grade wide-temperature devices to ensure stable operation in an environment of -20°C to 60°C.

[0082] In this embodiment, the wireless charging module and the base station communication module are linked through a control bus. When the communication module detects that the device's battery level is lower than the threshold, it sends a wake-up command to the wireless charging module to start the charging process. The charging status data is uploaded to the monitoring center through the 5G module, supporting remote query and fault diagnosis.

[0083] In terms of the fault tolerance mechanism, when a certain transmitting coil fails or there is a positioning deviation at the receiving end, the system automatically switches to an adjacent coil or adjusts the transmitting frequency to reconstruct the energy transmission link. Preferably, the receiving end is configured with a supercapacitor as a temporary energy storage unit to provide buffered power supply for the device during charging interruption.

[0084] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An explosion-proof wireless 4G / 5G base station for underground coal mine exploitation, characterized in that, Including: A communication module that integrates 4G / 5G communication protocols and supports wireless signal transmission; An antenna array that includes multi-band antennas with adjustable directions; An intelligent reflecting surface module deployed in the roadway for dynamically optimizing the electromagnetic wave propagation path; A distributed MIMO system that includes multiple distributed antenna units and a centralized control unit; An ultra-reliable and low-latency communication module that supports 5G network slicing technology; A wireless charging module for providing non-contact power supply to the base station and associated devices.

2. The explosion-proof wireless 4G / 5G base station for underground coal mine exploitation according to claim 1, wherein, The intelligent reflecting surface module includes: An adjustable reflector array configured to dynamically adjust the reflection angle; A signal analysis unit that uses AI algorithms to monitor signal attenuation and multipath effects in real time; A reflection parameter adjustment unit that automatically optimizes the reflection path based on environmental data.

3. The explosion-proof wireless 4G / 5G base station for underground coal mine exploitation according to claim 1, characterized in that, The communication module supports the millimeter wave band and realizes bandwidth optimization in the mine roadway through ultra-dense cell deployment.

4. An explosion-proof wireless 4G / 5G base station for underground coal mine exploitation according to claim 1, characterized in that, The antenna units of the distributed MIMO system adopt beamforming technology and dynamically adjust the power distribution and signal coverage of each antenna through AI algorithms.

5. An explosion-proof wireless 4G / 5G base station for underground coal mine exploitation according to claim 1, characterized in that, The URLLC module provides a dedicated low-latency channel for underground safety monitoring and personnel positioning tasks through 5G network slicing technology, with an end-to-end latency of less than 10 ms.

6. The explosion-proof wireless 4G / 5G base station for underground coal mine exploitation according to claim 1, wherein, The wireless charging module is based on the principle of electromagnetic induction to achieve non-contact energy transmission inside and outside the flameproof enclosure and supports simultaneous charging of multiple devices.

7. An explosion-proof wireless 4G / 5G base station for underground coal mine exploitation according to claim 1, characterized in that, The wireless charging module is linked with the intelligent battery management system to monitor the battery health status in real time and optimize the charge and discharge strategies.

8. An explosion-proof wireless 4G / 5G base station for underground coal mine excavation according to claim 1, characterized in that, The AI algorithm of the intelligent reflecting surface module includes a deep learning model, which is trained through the historical communication data and environmental parameters of the mine roadway to achieve predictive adjustment of the reflection path.

9. The explosion-proof wireless 4G / 5G base station for underground coal mine exploitation according to claim 1, characterized in that, The flameproof enclosure is made of carbon fiber composite material with embedded heat dissipation fins.

10. An explosion-proof wireless 4G / 5G base station for underground coal mine exploitation according to claim 1, characterized in that, The communication module integrates an edge computing unit for local processing of real-time monitoring data and realizes low-latency synchronization of data with the cloud server through 5G URLLC technology.

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