Signal transmission system for monitoring of a sanitation container

Abstract

This invention relates to the field of narrowband Internet of Things (IoT) technology and discloses a signal transmission system for monitoring sanitation containers. The system includes a signal acquisition unit, a signal feature extraction unit, and a channel coding configuration unit. The signal feature extraction unit extracts a discrete acceleration term representing the topological evolution state of the monitoring environment. The channel coding configuration unit determines the row and column dimensions of the interleaving matrix based on the mapping relationship between the discrete acceleration term and a reference threshold. When the term exceeds the reference threshold, the interleaving depth is increased. This invention uses the discrete acceleration term to represent transient multipath distortions generated by the physical environment and utilizes bitstream time-domain rearrangement to propagate burst errors on the time axis into random errors on the spatial axis. This proactively compensates for channel blockages caused by topological changes within the container without requiring base station feedback, ensuring the stability of narrowband IoT signal transmission.

Description

Technical Field

[0001] This invention belongs to the field of narrowband Internet of Things (IoT) technology, and particularly relates to a signal transmission system for monitoring sanitation containers. Background Technology

[0002] Currently, in urban infrastructure management, signal transmission systems used for monitoring sanitation containers typically employ sensors such as ultrasonic sensors to acquire liquid level parameters within the containers and utilize narrowband wireless communication networks to report status information to a remote monitoring backend center, thereby achieving unified scheduling and remote telemetry management of sanitation resources.

[0003] However, the deployment environment of buried or enclosed metal containers involves complex electromagnetic shielding and multipath fading. Especially when the physical filler inside the container undergoes transient displacement, the multipath reflection topology inside changes drastically. The resulting deep fading of the wireless transmission channel has obvious suddenness and transience. Existing narrowband IoT communication protocols mainly rely on the signal-to-noise ratio information fed back by the receiver to adjust the transmission power or redundancy factor. Since the time constant of the feedback link is much larger than the channel change rate induced by physical events, the system often cannot synchronously adjust the transmission strategy of the wireless link at the moment the signal is blocked. In addition, adopting linear improvement methods such as increasing the radio frequency transmission power or reducing the code rate will not only accelerate the consumption of node battery power, but also increase the probability of channel collisions for high-density monitoring nodes due to the extended data packet transmission time.

[0004] Therefore, how to synchronously guide the dynamic reconstruction of the physical layer coding matrix based on the physical characteristics of the sensor output signal in order to eliminate the signal shielding effect caused by sudden changes in the physical environment has become the technical problem to be solved by this invention. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A signal transmission system for monitoring sanitation containers, comprising:

[0006] The signal acquisition unit is used to acquire a sequence of measurement values ​​characterizing the endogenous changes in the environment monitored by the sanitation container;

[0007] The signal feature extraction unit, connected to the signal acquisition unit, is used to perform second-order discrete difference operations on the measurement value sequence to extract the discrete acceleration term of the signal that characterizes the topological evolution state of the monitoring environment.

[0008] The channel coding configuration unit, connected to the signal feature extraction unit, is used to establish the association mapping between the internal physical state of the sanitation container and the wireless channel topology, and includes the following logical distribution: Step 101, in response to the numerical fluctuation of the signal discrete acceleration term, determine the energy step intensity of the measured value sequence in the time domain to identify the transient multipath distortion characteristics of the sanitation container under metal shielding conditions; Step 102, based on the comparison result of the transient multipath distortion characteristics and the preset reference threshold, determine the row and column dimension combination of the interleaving matrix in the channel coding to adjust the interleaving depth; wherein, when the signal discrete acceleration term exceeds the preset reference threshold, the channel coding configuration unit increases the number of rows or columns of the interleaving matrix according to a preset ratio, and rearranges the bit stream to be transmitted caused by the sudden change in the internal physical state of the sanitation container in the time domain, so as to spread the burst error of the time axis caused by the transient multipath distortion into a uniformly distributed random bit error in the spatial axis, thereby actively compensating for the narrowband IoT signal blockage caused by the sudden change in the dielectric constant and spatial reflection topology inside the sanitation container without relying on the base station feedback link.

[0009] Preferably, the signal feature extraction unit extracts the discrete acceleration term of the signal in the following manner: Step 201, performs a first-order subtraction operation on the measurement value sequence at three consecutive sampling times to obtain a first-order difference sequence reflecting the rate of change of the internal state of the sanitation container; Step 202, performs a second-order subtraction operation on the first-order difference sequence to obtain the discrete acceleration term of the signal; wherein, the discrete acceleration term of the signal is used to characterize the amplitude of the energy mutation of the physical disturbance in the early stage of evolution, and the discrete acceleration term of the signal serves as the trigger source for reconstructing the interleaving matrix dimension to eliminate the lag in channel state information caused by the long delay of the feedback link in the narrowband IoT communication system.

[0010] Preferably, the signal acquisition unit includes at least one of an ultrasonic transducer module, an infrared detection module, an electrochemical gas sensing module, and a thermistor module; the measurement value sequence includes a displacement representing the overflow height inside the sanitation container, a voltage value representing the concentration of harmful gases, and a discrete frequency value representing the ambient temperature; the signal acquisition unit is used to convert the non-electrical physical parameters inside the sanitation container into a digital signal sequence for processing by the signal feature extraction unit.

[0011] Preferably, the channel coding configuration unit stores a deterministic mapping table; the mapping table records the correspondence between multiple signal discrete acceleration term intervals and multiple interleaving matrix dimension combinations; the channel coding configuration unit is used to retrieve the mapping table based on the signal discrete acceleration term output in real time by the signal feature extraction unit, and determine the number of rows and columns of the interleaving matrix required for the current transmission cycle, so as to achieve adaptive adjustment of physical layer parameters.

[0012] Preferably, the channel coding configuration unit further includes a buffer module; the buffer module is used to store the bit stream to be transmitted after error correction coding; the channel coding configuration unit performs row-by-row writing and column-by-column reading permutation processing on the bit stream to be transmitted in the buffer module according to the row and column dimensions of the interleaving matrix determined by step 101 or step 102, thereby improving the system's fault tolerance capability for multipath fading in the metal container by changing the arrangement order of the bit stream in the message frame.

[0013] Preferably, the channel coding configuration unit supports a narrowband IoT protocol stack; when the signal discrete acceleration term does not exceed the preset reference threshold, the channel coding configuration unit maintains the initial dimension of the interleaving matrix; when the signal discrete acceleration term exceeds the preset reference threshold, the interleaving depth is increased to combat multipath fading in a closed metal environment, ensuring that monitoring messages in emergency situations have a very high demodulation success rate when channel conditions are extremely deteriorated.

[0014] Preferably, while reconstructing the row and column dimensions of the interleaving matrix, the channel coding configuration unit simultaneously adjusts the redundancy of the forward error correction coding in the physical layer; the amplitude of the discrete acceleration term of the signal is negatively correlated with the code rate of the forward error correction coding; when the channel coding configuration unit detects severe physical disturbances, it increases the number of redundant check bits to collaboratively improve the message recovery capability of the signal transmission system in an environment with a signal-to-noise ratio of less than 5dB.

[0015] Preferably, the sampling frequency of the signal acquisition unit is greater than the message reporting frequency of the signal transmission system; the length of the measurement value sequence is determined by the message sending period, so that the discrete acceleration term of the signal in each reporting period can fully reflect the transient state distortion inside the sanitation container in that period; the signal feature extraction unit captures the surface signal fluctuation characteristics caused by container lid opening, garbage dumping or container displacement through high-frequency sampling.

[0016] Preferably, it also includes a management center unit; the channel coding configuration unit sends a monitoring data packet containing signal discrete acceleration term information and service monitoring data to the management center unit through a narrowband IoT wireless network; the management center unit performs graded early warning processing on the overflow status or safety risk status of the sanitation container according to the polarity and value of the received signal discrete acceleration term.

[0017] Compared with existing technologies, the signal transmission system for monitoring sanitation containers of the present invention has the following advantages:

[0018] 1. In the signal transmission of sanitation container monitoring, the second-order discrete difference of the sensor measurement value sequence is extracted to characterize the physical acceleration characteristics of the monitored target. This acceleration characteristic is then used to synchronously drive the dynamic reconstruction of the interleaving matrix dimension in the baseband coding stage, establishing a correlation mechanism between the physical motion state and the channel topology. This mechanism enables the remotely reported data packet containing measurement value information to obtain a burst error resistance depth matching the intensity of the physical disturbance at the moment of generation when a severe physical disturbance occurs inside the sanitation container, causing transient distortion of the electromagnetic wave reflection path. This achieves deep coupling between the measurement value monitoring data and the channel coding, improving the reliability of wireless transmission of measurement value signals using radio links in complex environments.

[0019] 2. By utilizing the acceleration characteristics of physical quantity changes as a pre-trigger source for transmission parameter adjustment, the system eliminates the problem of channel state information lag caused by long latency of feedback links in narrowband IoT telemetry systems using radio links. In the early stages of sudden deep fading in the physical environment, the system can actively adjust the interleaving depth without relying on historical information feedback from the receiver, transforming continuous bit errors on the time axis into randomly distributed bit errors on the spatial axis. This ensures the demodulation success rate of key measurement status signals in low signal-to-noise ratio environments and enhances the stability of wireless transmission of measurement signals between the monitoring device and the management center.

[0020] 3. By limiting the increase in coding redundancy to the characteristic period when the physical quantity acceleration exceeds the threshold, the method of setting a global high spreading factor in general technology to deal with uncertain fading is avoided. This method ensures the reliability of data transmission under abnormal conditions, while limiting the dwell time of radio signals in the air, maintaining the energy efficiency balance of each node in the system, and reducing the risk of channel conflict in high-density monitoring environment. Attached Figure Description

[0021] Figure 1 This is the logical architecture and flowchart of the signal transmission system for monitoring sanitation containers according to the present invention;

[0022] Figure 2 This is a processing logic interaction diagram of the signal transmission system of the present invention in a physical environment. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0024] A signal transmission system for monitoring sanitation containers, comprising:

[0025] The signal acquisition unit is used to acquire a sequence of measurement values ​​characterizing the endogenous changes in the environment monitored by the sanitation container;

[0026] The signal feature extraction unit, connected to the signal acquisition unit, is used to perform second-order discrete difference operations on the measurement value sequence to extract the discrete acceleration term of the signal that characterizes the topological evolution state of the monitoring environment.

[0027] The channel coding configuration unit, connected to the signal feature extraction unit, is used to establish the association mapping between the internal physical state of the sanitation container and the wireless channel topology, and includes the following logical distribution: Step 101, in response to the numerical fluctuation of the signal discrete acceleration term, determine the energy step intensity of the measured value sequence in the time domain to identify the transient multipath distortion characteristics of the sanitation container under metal shielding conditions; Step 102, based on the comparison result of the transient multipath distortion characteristics and the preset reference threshold, determine the row and column dimension combination of the interleaving matrix in the channel coding to adjust the interleaving depth; wherein, when the signal discrete acceleration term exceeds the preset reference threshold, the channel coding configuration unit increases the number of rows or columns of the interleaving matrix according to a preset ratio, and rearranges the bit stream to be transmitted caused by the sudden change in the internal physical state of the sanitation container in the time domain, so as to spread the burst error of the time axis caused by the transient multipath distortion into a uniformly distributed random bit error in the spatial axis, thereby actively compensating for the narrowband IoT signal blockage caused by the sudden change in the dielectric constant and spatial reflection topology inside the sanitation container without relying on the base station feedback link.

[0028] Preferably, the signal feature extraction unit extracts the discrete acceleration term of the signal in the following manner: Step 201, performs a first-order subtraction operation on the measurement value sequence at three consecutive sampling times to obtain a first-order difference sequence reflecting the rate of change of the internal state of the sanitation container; Step 202, performs a second-order subtraction operation on the first-order difference sequence to obtain the discrete acceleration term of the signal; wherein, the discrete acceleration term of the signal is used to characterize the amplitude of the energy mutation of the physical disturbance in the early stage of evolution, and the discrete acceleration term of the signal serves as the trigger source for reconstructing the interleaving matrix dimension to eliminate the lag in channel state information caused by the long delay of the feedback link in the narrowband IoT communication system.

[0029] Preferably, the signal acquisition unit includes at least one of an ultrasonic transducer module, an infrared detection module, an electrochemical gas sensing module, and a thermistor module; the measurement value sequence includes a displacement representing the overflow height inside the sanitation container, a voltage value representing the concentration of harmful gases, and a discrete frequency value representing the ambient temperature; the signal acquisition unit is used to convert the non-electrical physical parameters inside the sanitation container into a digital signal sequence for processing by the signal feature extraction unit.

[0030] Preferably, the channel coding configuration unit stores a deterministic mapping table; the mapping table records the correspondence between multiple signal discrete acceleration term intervals and multiple interleaving matrix dimension combinations; the channel coding configuration unit is used to retrieve the mapping table based on the signal discrete acceleration term output in real time by the signal feature extraction unit, and determine the number of rows and columns of the interleaving matrix required for the current transmission cycle, so as to achieve adaptive adjustment of physical layer parameters.

[0031] Preferably, the channel coding configuration unit further includes a buffer module; the buffer module is used to store the bit stream to be transmitted after error correction coding; the channel coding configuration unit performs row-by-row writing and column-by-column reading permutation processing on the bit stream to be transmitted in the buffer module according to the row and column dimensions of the interleaving matrix determined by step 101 or step 102, thereby improving the system's fault tolerance capability for multipath fading in the metal container by changing the arrangement order of the bit stream in the message frame.

[0032] Preferably, the channel coding configuration unit supports a narrowband IoT protocol stack; when the signal discrete acceleration term does not exceed the preset reference threshold, the channel coding configuration unit maintains the initial dimension of the interleaving matrix; when the signal discrete acceleration term exceeds the preset reference threshold, the interleaving depth is increased to combat multipath fading in a closed metal environment, ensuring that monitoring messages in emergency situations have a very high demodulation success rate when channel conditions are extremely deteriorated.

[0033] Preferably, while reconstructing the row and column dimensions of the interleaving matrix, the channel coding configuration unit simultaneously adjusts the redundancy of the forward error correction coding in the physical layer; the amplitude of the discrete acceleration term of the signal is negatively correlated with the code rate of the forward error correction coding; when the channel coding configuration unit detects severe physical disturbances, it increases the number of redundant check bits to collaboratively improve the message recovery capability of the signal transmission system in an environment with a signal-to-noise ratio of less than 5dB.

[0034] Preferably, the sampling frequency of the signal acquisition unit is greater than the message reporting frequency of the signal transmission system; the length of the measurement value sequence is determined by the message sending period, so that the discrete acceleration term of the signal in each reporting period can fully reflect the transient state distortion inside the sanitation container in that period; the signal feature extraction unit captures the surface signal fluctuation characteristics caused by container lid opening, garbage dumping or container displacement through high-frequency sampling.

[0035] Preferably, the second-order discrete difference operation in step 202 follows the following quantization logic: a(n) = x(n) - 2x(n-1) + x(n-2), where a(n) is the discrete acceleration term of the signal, x(n) is the measured value in the measurement value sequence at the current sampling time, x(n-1) is the measured value at the previous sampling time, and x(n-2) is the measured value at the sampling time before that. The signal feature extraction unit uses the quantization logic to calculate the difference in the rate of change between adjacent sampling points to determine the characteristic trend of the evolution of the physical environment.

[0036] Preferably, it also includes a management center unit; the channel coding configuration unit sends a monitoring data packet containing signal discrete acceleration term information and service monitoring data to the management center unit through a narrowband IoT wireless network; the management center unit performs graded early warning processing on the overflow status or safety risk status of the sanitation container according to the polarity and value of the received signal discrete acceleration term.

[0037] Example 1: Under this condition, the transient free fall and accumulation of a large amount of wet waste causes transient physical distortions in the dielectric constant inside the metal container and the spatial electromagnetic wave reflection topology. This physical motion directly induces transient multipath distortion in the wireless channel, resulting in dense burst communication interruptions. Although the transient multipath fading of the wireless radio frequency channel occurs within a symbol transmission period in the microsecond to millisecond range, and the structural displacement caused by the physical dumping is a low-frequency mechanical motion, the mechanical displacement of the physical interface (on the order of hundreds of milliseconds) must precede the electromagnetic wave reflection topology distortion induced by it in the causal chain. This system does not forcibly track radio frequency phase changes on a microsecond scale, but rather uses the initial acceleration of the overall motion as a feedforward prediction source. When the signal characteristics... When the feature extraction unit captures the initial discrete acceleration change through 10Hz sampling, due to the inherent physical time difference between the start of the object's fall and the full formation of multipath deep fading, the system uses this time difference to inject deep interleaving redundancy in advance during the subsequent RF data packet generation stage. Thus, by utilizing the lead time difference of the overall motion, a cross-scale feedforward compensation closed loop for transient distortion of surface RF electromagnetic waves is achieved. Since conventional narrowband wireless communication networks rely on the receiver to feedback historical signal-to-noise ratio to adjust the transmit power or redundancy factor, the time constant of this feedback link is greater than the rate of physical damage, causing the system to experience state lag when facing sudden fading, resulting in the loss of data packets containing overflow or fire alarm status data the instant the channel is blocked.

[0038] To address the long-delay feedback failure state caused by the aforementioned physical disturbance, the signal acquisition unit in the system continuously acquires a sequence of displacement measurements representing the overflow height inside the sanitation container at a sampling frequency of 10Hz. The signal feature extraction unit extracts the measurement sequence from three consecutive sampling times and calculates a quadratic discrete difference. The specific difference calculation follows the formula a(n)=x(n)-2x(n-1)+x(n-2), where a(n) is the extracted discrete acceleration term of the signal, x(n) is the displacement measurement value in the measurement sequence at the current sampling time, x(n-1) is the displacement measurement value at the previous sampling time, and x(n-2) is the displacement measurement value at the sampling time before that. This quadratic discrete difference operation converts the physical displacement... The data is converted into kinematic derivatives that characterize the topological evolution of the physical environment. This allows the system to perceive channel blocking risks based on the evolution trend of local physical characteristics as a pre-triggered source. Specifically, the energy step intensity of the measured value sequence in the time domain is defined as the rate of drastic change of the amplitude of the discrete acceleration term of the signal within adjacent sampling periods. The signal feature extraction unit generates the energy step intensity value by extracting the absolute difference between the discrete acceleration term of the signal in the current sampling period and the discrete acceleration term of the signal in the previous sampling period. When this value suddenly jumps, the system determines that the physical filling has undergone transient irregular collision or displacement. Thus, without the need for external probe intervention, the transient multipath distortion characteristics of the sanitation container under metal shielding conditions can be accurately identified.

[0039] In response to the numerical fluctuations of the signal discrete acceleration term, the channel coding configuration unit establishes a mapping relationship between the signal discrete acceleration term, which characterizes the amplitude of the initial energy mutation of the physical disturbance, and the interleaving matrix dimension of the baseband physical layer. When the absolute value of the signal discrete acceleration term exceeds a preset reference threshold, the channel coding configuration unit retrieves the internally stored mapping table and extracts the corresponding interleaving matrix dimension combination. It increases the number of rows or columns of the interleaving matrix according to a preset ratio to adjust the interleaving depth, and simultaneously completes matrix permutation by writing row-wise and reading column-wise the error-corrected encoded bitstream to be transmitted through the internal cache module. This interleaving matrix reconstruction mechanism maintains the original... Under the conditions of RF transmission duration and transmission power settings, by changing the temporal arrangement order of the bit stream within the message frame, a bit stream rearrangement structure matching the current physical disturbance intensity is injected into the monitoring data packet containing service monitoring data. This suppresses the system energy consumption increase caused by conventionally increasing the spreading factor, ensuring the compliance of the dynamically interleaved bit stream transmission and the coherence of demodulation within the narrowband IoT standard protocol stack. The channel coding configuration unit constructs an interleaving matrix at the application layer. The system extracts service monitoring data and appends a sequence header of the signal discrete acceleration term of the current sampling period to generate the application layer bit stream to be transmitted. The channel coding configuration unit then uses a preset calibration formula... Real-time calculation of the number of rows in the interleaving matrix, where, denoted as the baseline row number under static, undisturbed conditions, k is the dimensionless expansion coefficient characterizing the current spatial multipath sensitivity of the metal container, and a(n) is the discrete acceleration term of the signal extracted in real time.

[0040] The channel coding configuration unit writes the application layer bitstream to be transmitted row by row into the reconstructed interleaving matrix and reads it column by column to output the rearranged bitstream. The system submits the rearranged bitstream as the standard user data payload to the lower layer and encapsulates it into a standard subframe of the narrowband IoT physical uplink shared channel. This allows the base station network element physical layer to perform transparent transmission without being aware of changes in the application layer interleaving dimension, in accordance with standard signaling. The management center unit parses a(n) in the data packet header and synchronously reconstructs the inverse interleaving matrix to complete end-to-end error recovery. On this transparent transmission architecture, to achieve synchronous adjustment of the redundancy of the physical layer forward error correction coding by the channel coding configuration unit, this system utilizes the cross-layer control mechanism of the protocol stack. Before submitting the rearranged bitstream to the physical layer, the channel coding configuration unit sends dynamic updates on the number of repeated transmissions and the modulation and coding scheme (MCS) level through the standard AT signaling interface of the baseband communication module. The configuration command specifies that the larger the absolute value of the discrete acceleration term of the signal, the lower the MCS order set by the channel coding configuration unit and the higher the number of repeated transmissions. This increases the number of forward error correction redundancy check bits of the physical layer service channel without modifying the underlying network element demodulation protocol and maintaining transparent transmission of payload data. After matrix permutation in the above dimensions, the reconstructed interleaving matrix converts continuous burst channel errors triggered by physical motion on the time axis into random errors uniformly distributed on the spatial axis. This enables the forward error correction coding mechanism of the physical layer to perform random error correction, maintaining the demodulation output stability of the monitoring message in metal shielding conditions with a signal-to-noise ratio of less than 5dB. The signal transmission system establishes an autonomous feedforward compensation closed loop for burst electromagnetic interference conditions by converting the kinematic derivatives of the sensor's non-electrical physical parameters into adjustment trigger quantities in the physical layer channel coding dimension.

[0041] Example 2: The physical testing of the current signal transmission system is carried out using a microwave anechoic chamber testing platform. The testing platform includes a closed metal chamber with an internal volume of 2 cubic meters. A signal acquisition unit with a measurement resolution of 1.0 mm is installed on the top of the metal chamber. Multiple sets of irregular metal baffles driven by servo motors are installed at the bottom of the metal chamber. The servo motors drive the metal baffles to move, generating random physical spatial topology changes. The testing platform injects Gaussian white noise with a signal-to-noise ratio of 15.0 dB into the baseband processing link. At the same time, the testing platform superimposes power frequency harmonic interference with a center frequency of 50 Hz, outputting reference input data simulating a real industrial electromagnetic environment. The sampling frequency of the signal acquisition unit is determined based on the transient physical motion tracking requirements and the power consumption constraints of the terminal node during sleep. The testing platform sets the upper limit of the random motion linear velocity of the metal baffles to 1.5 m / s. The control logic extracts the ratio of the linear velocity of the metal baffles to the depth of the closed metal chamber and calculates the target sampling period. The system's judgment rule limits the selection of the upper limit of the preset sampling frequency range when the displacement change rate of the monitoring interface is greater than 0.8 m / s. Based on the above judgment rule, the system sets the sampling frequency of the signal acquisition unit to 10 Hz.

[0042] A metal baffle falls freely with an initial velocity of 1.2 m / s for 0.5 s. During this time window, the signal acquisition unit outputs a sequence of measurement values ​​including environmental noise. The signal feature extraction unit receives the measurement sequence, calculates the quadratic discrete difference of three consecutive sampling points, and outputs the discrete acceleration term of the signal. During the stationary phase of the metal baffle, the discrete acceleration term of the signal is in the range of 0.02 m / s² to 0.05 m / s². From the start of the metal baffle's fall to 125.0 ms, due to the abrupt change in the physical interface, the signal output by the signal feature extraction unit deviates from its initial velocity. The discrete acceleration term value jumps to 1.85 m / s². The channel coding configuration unit extracts the aforementioned jump in discrete acceleration term, retrieves the preset mapping table, and reconstructs the dimension of the physical layer interleaving matrix. The test platform is set up with four test groups based on the same input reference. The control group maintains the fixed dimension of the interleaving matrix preset in the channel coding standard protocol. Test group 1 expands the number of rows of the interleaving matrix to 1.5 times the initial value. Test group 2 expands the number of rows of the interleaving matrix to 2.5 times the initial value. The out-of-range control group expands the number of rows of the interleaving matrix to 5.0 times the initial value.

[0043] The test platform controlled the movement of a metal baffle to generate a physical multipath fading channel blockade lasting 300.0 ms, and read the demodulation statistics from the receiver. Under the condition of superimposed 15.0 dB Gaussian white noise, the control group maintained static interleaving parameters, and its receiver experienced 18 consecutive demodulation errors, with a demodulation success rate of 42.3% for monitored data packets. Experimental group 1 applied 1.5 times the interleaving depth extension, and the continuous bit errors showed a discrete distribution on the data frame space axis, with a demodulation success rate of 87.6%. Experimental group 2 applied 2.5 times the interleaving dimension extension, and the burst channel errors were dispersed into random bit errors and eliminated by the forward error correction mechanism, achieving a demodulation success rate of 99.1%. The out-of-range control group applied 5.0 times the interleaving dimension extension. The demodulation success rate was 99.2%; in the out-of-range control group, the buffer wait time for the interleaving module to read the bit stream column by column increased to 2150.0ms, which is greater than the 2000.0ms physical layer maximum processing delay limit specified by the narrowband IoT communication protocol. The inflection point data of the above performance test shows that the interleaving matrix expansion ratio in the range of 1.5 to 3.0 times constitutes a technical balance between anti-burst bit error capability and baseband processing delay; the channel coding configuration unit dynamically adjusts the interleaving matrix dimension according to the signal discrete acceleration term. Under the condition of maintaining the original RF transmit power setting, the system has a message demodulation success rate of more than 99.0% when experiencing transient electromagnetic topology distortion, realizing stable data transmission under fading channels.

[0044] Example 3: The current signal transmission system is initially deployed in underground metal sanitation containers with different volume specifications and inner wall materials; the background electromagnetic reflection topology of different containers and their mechanical response characteristics when facing garbage dumping have physical differences; using a fixed static threshold and mapping association setting can easily lead to the system triggering code reconstruction under environmental micro-vibration conditions, or the interleaving depth extension being lower than the channel multipath distortion compensation requirement under garbage dumping conditions; to establish the boundary of the aforementioned preset reference threshold, the system starts a parameter calibration program based on the on-site physical state before service operation; the signal acquisition unit acquires a 24-hour sequence of no-load background displacement measurements in a closed metal container without service operation; the signal feature extraction unit calculates the quadratic values ​​of all consecutive sampling times in the no-load background displacement measurement sequence. Discrete differential analysis extracts the maximum absolute value of the discrete acceleration term sequence of the obtained signal. The system control module adds this maximum absolute value to a fixed compensation margin of 0.2 m / s², sets the sum as a preset reference threshold, and writes it into local memory to construct a trigger benchmark aligned with the current container structure. To construct the mapping relationship table, the calibration program releases the test weight sequentially in a gradient height of 0.5 m to 2.0 m within the closed metal container. The signal feature extraction unit records the peak signal discrete acceleration term triggered by each release action. The system control module extracts the burst error block length of the baseband communication link at this specific release moment and calculates its ratio to the column width of the narrowband IoT interleaving matrix. The system control module determines the matrix row multiplication factor based on the round-up algorithm, defining the initial state and quantization benchmark of the calibration process.

[0045] Before starting the calibration program, lock the test environment temperature and write the initial baseline row number to local memory. and fixed interlacing column width After obtaining the discrete acceleration terms of the peak signal corresponding to different release heights, the system control module extracts the length of the continuously lost symbol sequence at the communication receiver and defines it as the measured burst error block length. According to the calculation formula The spatial multipath sensitivity expansion coefficient of the metal container is determined, where k is the dimensionless expansion coefficient to be calibrated, and λ is the system's preset fixed compensation tolerance factor. To measure the length of burst error blocks, To fix the column width of the interleaving matrix, To obtain the peak signal discrete acceleration term corresponding to the release action, the system substitutes multiple sets of gradient release test data into the calibration formula, takes the arithmetic mean, and generates a specific expansion coefficient k for the current sanitation container. This coefficient is then stored in the storage module for direct access in subsequent business cycles, thus mitigating the risk of deviation from relying on general empirical values. The channel coding configuration unit establishes data binding between the feature intervals of the signal discrete acceleration term extracted at different release heights and the corresponding matrix row multiplication coefficients, generating a mapping table adapted to the characteristics of the current specific container. Through the above-mentioned quantization acquisition and feature mapping process, the system transforms the static threshold setting into a parameter determination mechanism based on on-site physical response data. This parameter determination mechanism avoids message loss caused by insufficient interleaving depth expansion, suppresses the increase in baseband processing latency caused by excessive interleaving dimension, and maintains the adaptability of narrowband IoT communication resources under sudden electromagnetic interference conditions.

[0046] Example 4: When the signal transmission system faces the condition that the inner wall structure of the buried metal sanitation container deforms due to long-term temperature cycling and mechanical fatigue, causing a slow drift in the background electromagnetic reflection topology, the signal feature extraction unit activates a timeliness guarantee and reconstruction mechanism based on a sliding time window. This mechanism extracts the sequence of unloaded background displacement measurements acquired by the signal acquisition unit within seven consecutive days of no business during the daily system sleep period. The control logic calculates the arithmetic mean of the measurement sequence within this time window to update the basic compensation baseline. The control logic calculates the quadratic discrete difference sequence of the measurement sequence in the current sampling period and weights and fuses the maximum absolute value of the quadratic discrete difference sequence of the current period with the basic compensation baseline to output an updated preset reference threshold. The aforementioned weighted fusion operation follows the formula... Where T is the updated preset reference threshold, The preset reference threshold of the previous sampling period. The maximum absolute value of the quadratic discrete difference sequence within the current sliding time window. As the first weighting coefficient, This is the second weighting coefficient.

[0047] The channel coding configuration unit receives the updated preset reference threshold and overwrites the triggering start point of the mapping table in the local memory with the updated preset reference threshold. When the signal discrete acceleration term extracted in subsequent service cycles is greater than the updated preset reference threshold, the channel coding configuration unit increases the number of rows and columns of the interleaving matrix according to the updated mapping table. The aforementioned timeliness guarantee and reconstruction mechanism eliminates static background drift interference caused by container aging and maintains the stability of the transient multipath distortion feature boundary perceived by the signal feature extraction unit. The signal transmission system maintains an adaptive anti-burst fading transmission state over a long lifespan without human intervention.

[0048] Example 5: In a buried metal sanitation container containing residual waste and undergoing high-temperature fermentation, fluctuations in the mixed gas concentration inside the container and the measured overflow height cause nonlinear coupling interference. The measurement sequence obtained solely by the displacement sensor generates a pseudo-acceleration term due to the drift in the refractive index of the environmental medium, triggering unnecessary interleaving matrix reconstruction. To address the detection interference caused by these environmental medium changes, the signal acquisition unit initiates an adaptive parameter matrix calibration procedure adapted to the complex biochemical environment. It uses a built-in infrared detection module to obtain the gas transmittance inside the container and calculates the compensation factor for the ultrasonic velocity based on the current ambient temperature, thereby correcting the original measurement sequence. Before calculating the second-order discrete difference, the signal feature extraction unit retrieves the adaptive adjustment operator K from the local memory. The value of operator K is determined through a logical relation... Determined; where K is the adaptive adjustment operator, λ is the sensitivity correction coefficient with a value of 0.15, and ΔC is the percentage difference between the current gas concentration and the empty reference concentration. This calculation step separates the physical disturbance component generated by biochemical degradation from the signal discrete acceleration term. The linear mapping relationship and the value of the sensitivity correction coefficient are based on the experimental derivation of the thermodynamic and acoustic propagation characteristics of the gas in the closed container. Since the acoustic impedance of fermentation gases such as methane and hydrogen sulfide in the container is different from that of standard air, the experiment shows that when the percentage difference in the mixed gas concentration ΔC fluctuates by 10%, the transit time of the ultrasonic wave within a fixed line of sight will produce a phase hysteresis of about 1.5%, which in turn leads to pseudo physical acceleration in the displacement calculation.

[0049] The system precisely offsets the sound velocity error limit induced by changes in medium density at the algebraic multiplicative end by anchoring the sensitivity correction coefficient λ to 0.15. If this coefficient is set below 0.10, it cannot cover the high-concentration gas distortion boundary during the high-temperature fermentation period. If the coefficient is set above 0.20, it will mistakenly filter out the real minute vibrations caused by slight physical collisions with the container, causing the anti-fading pre-triggering mechanism to fail. After the correction by the above adaptive operator, the corrected signal discrete acceleration term represents the sudden distortion of the mechanical topology inside the container. The channel coding configuration unit responds to the corrected signal discrete acceleration term to locate the number of rows and columns of the interleaving matrix. The aforementioned parameter matrix calibration procedure eliminates the environmental background noise step caused by the chemical reaction inside the container, preventing the accidental triggering and consumption of physical layer resources. The system presents a stable transmission performance that is compatible with fluctuations in environmental biochemical characteristics, ensuring the reliability of the monitoring data reporting logic in harsh underground environments.

[0050] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit of this application and the scope of protection of this invention, and all of these forms are within the protection scope of this application.

Claims

1. A signal transmission system for monitoring of a sanitation container, characterized in that include: The signal acquisition unit is used to acquire a sequence of measurement values ​​characterizing the endogenous changes in the environment monitored by the sanitation container; The signal feature extraction unit, connected to the signal acquisition unit, is used to perform second-order discrete difference operations on the measurement value sequence to extract the discrete acceleration term of the signal that characterizes the topological evolution state of the monitoring environment. The channel coding configuration unit, connected to the signal feature extraction unit, is used to establish the association mapping between the physical state inside the sanitation container and the wireless channel topology, and includes the following logical distribution: Step 101, in response to the numerical fluctuation of the discrete acceleration term of the signal, the energy step intensity of the measurement value sequence in the time domain is determined in order to identify the transient multipath distortion characteristics of the sanitation container under the metal shielding condition. Step 102: Based on the comparison results between transient multipath distortion characteristics and preset reference thresholds, determine the row and column dimension combination of the interleaving matrix in channel coding to adjust the interleaving depth. Among them, when the signal discrete acceleration term exceeds the preset reference threshold, the channel coding configuration unit increases the number of rows or columns of the interleaving matrix according to a preset ratio. By performing time-domain rearrangement of the bit stream to be transmitted caused by the sudden change in the physical state inside the sanitation container, the burst errors on the time axis caused by transient multipath distortion are spread into uniformly distributed random errors on the spatial axis. Thus, without relying on the base station feedback link, it actively compensates for the narrowband IoT signal blockage caused by the sudden change in dielectric constant and spatial reflection topology inside the sanitation container.

2. A signal transmission system for monitoring of a waste container according to claim 1, characterized in that, The signal feature extraction unit extracts the discrete acceleration term of the signal in the following way: Step 201, performs a first-order subtraction operation on the measurement value sequence at three consecutive sampling times to obtain a first-order difference sequence reflecting the rate of change of the internal state of the sanitation container; Step 202, performs a second-order subtraction operation on the first-order difference sequence to obtain the discrete acceleration term of the signal; wherein, the discrete acceleration term of the signal is used to characterize the amplitude of the energy mutation of the physical disturbance in the early stage of evolution, and the discrete acceleration term of the signal serves as the trigger source for reconstructing the interleaving matrix dimension to eliminate the lag in channel state information caused by the long delay of the feedback link in the narrowband IoT communication system.

3. The signal transmission system for monitoring sanitation containers according to claim 1, characterized in that, The signal acquisition unit includes at least one of an ultrasonic transducer module, an infrared detection module, an electrochemical gas sensing module, and a thermistor module; the measurement value sequence includes the displacement representing the overflow height inside the sanitation container, the voltage value representing the concentration of harmful gases, and the discrete frequency value representing the ambient temperature; the signal acquisition unit is used to convert the non-electrical physical parameters inside the sanitation container into a digital signal sequence for processing by the signal feature extraction unit.

4. The signal transmission system for monitoring sanitation containers according to claim 1, characterized in that, The channel coding configuration unit stores a deterministic mapping table; the mapping table records the correspondence between multiple signal discrete acceleration term intervals and multiple interleaving matrix dimension combinations; the channel coding configuration unit is used to retrieve the mapping table based on the signal discrete acceleration terms output in real time by the signal feature extraction unit, and determine the number of rows and columns of the interleaving matrix required for the current transmission cycle, so as to achieve adaptive adjustment of physical layer parameters.

5. A signal transmission system for monitoring sanitation containers according to claim 1, characterized in that, The channel coding configuration unit also includes a buffer module; the buffer module is used to store the bit stream to be transmitted after error correction coding; the channel coding configuration unit performs row-by-row writing and column-by-column reading permutation processing on the bit stream to be transmitted in the buffer module according to the row and column dimensions of the interleaving matrix determined by step 101 or step 102, thereby improving the system's fault tolerance capability for multipath fading in the metal container by changing the arrangement order of the bit stream in the message frame.

6. The signal transmission system for monitoring sanitation containers according to claim 1, characterized in that, The channel coding configuration unit supports narrowband IoT protocol stacks; when the signal discrete acceleration term does not exceed the preset reference threshold, the channel coding configuration unit maintains the initial dimension of the interleaving matrix; When the signal discrete acceleration term exceeds the preset reference threshold, the interleaving depth is increased to combat multipath fading in a closed metal environment, ensuring that monitoring messages in emergency situations have a very high demodulation success rate when channel conditions are extremely deteriorated.

7. A signal transmission system for monitoring sanitation containers according to claim 1, characterized in that, While reconstructing the row and column dimensions of the interleaving matrix, the channel coding configuration unit simultaneously adjusts the redundancy of the forward error correction coding in the physical layer; the amplitude of the discrete acceleration term of the signal is negatively correlated with the code rate of the forward error correction coding; when the channel coding configuration unit detects severe physical disturbances, it increases the number of redundant check bits to collaboratively improve the message recovery capability of the signal transmission system in environments with a signal-to-noise ratio of less than 5dB.

8. A signal transmission system for monitoring sanitation containers according to claim 1, characterized in that, The sampling frequency of the signal acquisition unit is greater than the message reporting frequency of the signal transmission system; the length of the measurement value sequence is determined by the message sending period, so that the discrete acceleration term of the signal in each reporting period can fully reflect the transient state distortion inside the sanitation container in that period. The signal feature extraction unit captures surface signal fluctuations caused by container lid opening, garbage dumping, or container displacement through high-frequency sampling.

9. A signal transmission system for monitoring sanitation containers according to claim 1, characterized in that, It also includes a management center unit; the channel coding configuration unit sends monitoring data packets containing signal discrete acceleration term information and business monitoring data to the management center unit through a narrowband IoT wireless network; the management center unit performs graded early warning processing on the overflow status or safety risk status of the sanitation container according to the polarity and value of the received signal discrete acceleration term.

Images