A wireless data transmission method and system based on substation spatial propagation state

Abstract

This invention discloses a wireless data transmission method and system based on the spatial propagation states of a substation. The method includes: identifying several stable propagation states of communication signals within the substation space based on the spatial distribution structure of the substation, constructing a set of substation spatial propagation states, and based on this set, obtaining the wireless signal propagation response corresponding to each propagation state and calculating the correlation coefficient between different propagation states; co-coding the original transmitted wireless data according to the correlation coefficient of the propagation states, and optimizing the process by maximizing mutual information constraints to achieve effective responses between each propagation state and the original signal during the co-coding process; and jointly decoding the wireless signals from multiple spatial propagation states at the receiving end to achieve multi-path cooperative data transmission based on the spatial propagation states of the substation. This invention can significantly improve the received signal-to-noise ratio of wireless communication signals.

Description

Technical Field

[0001] This invention relates to the field of data communication technology for substations, specifically to a wireless data transmission method and system based on the spatial propagation state of a substation. Background Technology

[0002] The primary and secondary equipment and metal frame in the substation are densely arranged, forming a complex three-dimensional spatial structure consisting of circuit breakers, disconnect switches, busbars, supports and grounding grids. Communication signals inevitably experience multiple reflections, diffractions and blockages during propagation, and their propagation characteristics are significantly different from those of conventional open environments or communication equipment rooms.

[0003] Existing substation communication methods typically treat multipath effects as random fading or interference and compensate using equalization, diversity, or retransmission mechanisms based on statistical channel models. However, these methods do not fully utilize the deterministic propagation characteristics induced by the long-term stable existence of the spatial structure within the substation. Under conditions of dense equipment and strong electromagnetic interference, communication reliability remains limited. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a data communication method that can explicitly describe the impact of substation spatial structure on signal propagation and utilize multiple stable propagation paths for coordinated transmission, so as to improve the transmission stability and reliability of substation operation data.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A wireless data transmission method based on the spatial propagation state of a substation includes: Based on the spatial distribution structure of primary equipment, secondary equipment and metal frame in the substation, identify several stable propagation states of communication signals in the substation space and construct a set of substation spatial propagation states. Based on the set of spatial propagation states in the substation, the wireless signal propagation response corresponding to each propagation state is obtained, and the correlation coefficient between different propagation states is calculated. Based on the correlation coefficient of the propagation state, the original transmitted wireless data is co-coded so that the original data information is mapped to multiple spatial propagation states and carried and represented in a correlated manner. With maximizing mutual information constraints as the optimization objective, the effective response between each propagation state and the original signal is achieved during the co-coding process. At the receiving end, wireless signals from multiple spatial propagation states are jointly decoded. By setting the weight vector during the joint decoding process, the optimal merging selection of multi-path signals is ensured, thereby realizing multi-path collaborative data transmission based on the spatial propagation state of the substation.

[0007] Furthermore, in the substation spatial propagation state set, the propagation state variables of the communication nodes include at least one or more of the following: wireless signal received power, signal-to-noise ratio, bit error rate, and link reachability probability, used to characterize the information transmission state of the communication nodes under different propagation conditions; wherein, the substation spatial propagation state set is represented as: ; In the formula, For the set of spatial propagation states of the substation, This refers to the number of stable spatial propagation states that can be distinguished by measurement or modeling between wireless communication node pairs in the current substation. In the substation space, the first [object] is formed by the combination of specific equipment surface relationships, reflection, diffraction, and propagation constraints. A stable state of propagation.

[0008] Furthermore, the evolution of the propagation state variables over time is described by updating the substation spatial propagation state set in discrete time. The update of the substation spatial propagation state set is based on the propagation state variables at adjacent times and environmental disturbance factors to predict the propagation state at the current time. Among these, the spatial propagation state... Defined as: ; In the formula, This is a set of parameters describing the equivalent spatial propagation trajectory of a wireless signal as it travels from the transmitter to the receiver within a substation, after one or more reflections and diffractions. This is the set of electromagnetic physical property parameters of all propagation media and reflectors related to the propagation state. A set of spatial and structural constraints to limit or stabilize the existence of propagation states.

[0009] Furthermore, the parameters of the equivalent spatial propagation trajectory are determined by the relationship between the equipment and space within the substation, and the parameter description set of its equivalent spatial propagation trajectory is as follows. Defined as: ; Electromagnetic physical characteristic parameter set Determined by all propagation media and reflectors along the wireless signal propagation path, it is used to quantitatively characterize the physical modulation effect of primary equipment and metal structure within a substation on wireless signals, and is defined as follows: ; Set of spatial and structural constraints The wireless data transmission constraints are determined by the inherent equipment locations within a given substation, and are defined as follows: ; In the formula, The equivalent length of the propagation path determined by the device geometry. The effective number of reflections and diffractions is determined by the number of surfaces on the equipment. Let be the set of incident angles determined by spatial geometric relations. Let the set of reflection and diffraction angles be determined by the surface normal of the device. The equivalent dielectric constant of the insulating material, The relative permeability of the technical structure, The relative electrical conductivity of the metal surface. The equivalent reflection coefficient, The degree to which the data transmission path is blocked. For data transmission latency, The degree to which the location of the station's inherent equipment is fixed.

[0010] Furthermore, the wireless signal propagation response corresponding to each propagation state is obtained, expressed by the following formula: ; In the formula, for Time travels through space propagation state Received signal, The set of parameter descriptions for trajectories propagating from the equivalent space The set of parameters of the equivalent spatial propagation trajectory and electromagnetic physical property parameters. The set of dielectric electromagnetic property parameters and spatial and structural constraints in the medium The propagation state equivalent channel response function is determined by the spatial and structural constraints in the equation. The original transmitted signal, This refers to noise signals within the substation.

[0011] Furthermore, the equivalent channel response function of the propagation state is expressed by the following formula: ; In the formula, Let be the propagation state equivalent channel response function. The equivalent reflection coefficient, For the first k Spatial propagation path attenuation factor of a spatial propagation state For delay The Dirac impulse function, For data transmission latency, The propagation attenuation index is determined by the internal structure of a given substation.

[0012] Furthermore, the correlation coefficients between different propagation states are calculated using the following method: ; in, ; In the formula, For the first Space propagation state With the Space propagation state The degree of correlation between them The average of the samples is shown in bold. For time window, for Time travels through space propagation state Received signal, for Time travels through space propagation state The received signal.

[0013] Furthermore, the original data information is mapped onto multiple spatial propagation states and represented in a correlated manner as follows: ; The constraint for maximizing mutual information is: ; ; In the formula, For the collaborative coding matrix, In order to make The cooperative coding matrix that yields the minimum value W Values, The Frobenius norm is used to measure the deviation between the actual encoded related structure and the target structure. The spatial propagation state correlation matrix, The target-related constraint matrix, For mutual information measurement, for Time passes Space propagation state Received signal, For the set of spatial propagation states from the substation The selected subset of propagation states participating in cooperative transmission. The original transmitted signal, For determinant operations, Indicates and Identity matrices of the same dimension This represents the average power of the transmitted signal. This represents the equivalent noise power in a single spatial propagation state. Represents a subset of propagating states The corresponding equivalent propagation state channel response vector or matrix, Represents a subset of propagating states The noise covariance matrix is ​​used to characterize the differences in noise experienced by different propagation states under strong electromagnetic interference conditions in substations. For matrix transpose, It is a logarithm.

[0014] Furthermore, at the receiving end, the wireless signals from multiple spatial propagation states are jointly decoded, and the equivalent received signal is represented as: ; The weight vector in the joint decoding process is obtained in the following way: ; In the formula, The equivalent received signal recovered after joint decoding. For joint decoding of the weight vector, For matrix transpose, for The signals received at all times The covariance matrix of the received signal in multiple propagation states. The noise covariance matrix is ​​given by the electromagnetic environment of the substation. It is the propagation state response vector composed of the equivalent channel responses of each spatial propagation state.

[0015] The present invention also provides a system for applying the above-described wireless data transmission method based on the spatial propagation state of a substation, comprising: The spatial propagation state identification module is used to identify several stable propagation states of communication signals formed in the substation space based on the spatial distribution structure of primary equipment, secondary equipment and metal frame in the substation, and to construct a set of spatial propagation states of the substation. The propagation state response modeling module is used to obtain the wireless signal propagation response corresponding to each propagation state based on the spatial propagation state set of the substation, and to calculate the correlation coefficient between different propagation states. The cooperative coding module is used to cooperatively code the original transmitted wireless data based on the correlation coefficient of the propagation state, so that the original data information is mapped to multiple spatial propagation states and carried and represented in a correlated manner. With maximizing mutual information constraints as the optimization goal, it realizes the effective response between each propagation state and the original signal during the cooperative coding process. The joint decoding module is used to jointly decode wireless signals from multiple spatial propagation states at the receiving end. By setting the weight vector during the joint decoding process, the optimal merging selection of multi-path signals is ensured, thereby realizing multi-path collaborative data transmission based on the spatial propagation state of the substation.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention discloses a multi-path cooperative wireless data transmission method and system based on the spatial propagation state of a substation. By constructing a substation spatial propagation state model, it systematically models and utilizes the wireless signal propagation state induced by the long-term stability of primary equipment, secondary equipment, and metal structures within the substation. The method uses the spatial propagation state as the core characterization unit, comprehensively describing the equivalent propagation trajectory, electromagnetic medium characteristics, and spatial constraints of wireless signals formed by reflection, diffraction, and obstruction in the complex spatial environment of the substation. Based on this, it obtains the signal propagation response corresponding to each propagation state and establishes the correlation relationship between different spatial propagation states through statistical analysis.

[0017] This invention introduces a cooperative coding mechanism based on propagation state correlation. It maps the original transmitted data to multiple spatial propagation states for correlation carrying. By constructing a propagation state correlation matrix and introducing target correlation constraints, it achieves active control over the statistical structure of multipath signals. Simultaneously, with maximizing mutual information as the optimization objective, it selects a subset of propagation states from the set of spatial propagation states to participate in cooperative transmission, fully exploiting the effective information gain inherent in multipath propagation within the complex spatial environment of substations. At the receiving end, it further combines the statistical correlation and noise covariance characteristics of the received signals from the spatial propagation states to construct a joint decoding weight vector, achieving optimal merging and reliable recovery of signals from multiple propagation states.

[0018] The results show that, in substation environments with metal equipment obstruction and strong electromagnetic interference, compared with single-path wireless transmission, the method of the present invention can significantly improve the received signal-to-noise ratio of wireless communication signals, reduce the communication error rate, improve the effective data throughput and end-to-end transmission stability, and enhance the reliability and anti-interference capability of wireless communication in the complex electromagnetic environment of substations, thus showing good prospects for engineering applications.

[0019] In summary, the multipath cooperative wireless data transmission method and system based on the spatial propagation state of substations of the present invention breaks through the traditional communication design concept that regards multipath effects as an unfavorable factor. It transforms the stable propagation state induced by the complex spatial structure of substations into a modelable and usable communication resource, overcomes the problem of insufficient link reliability of existing wireless communication schemes in environments with strong reflection, strong diffraction and strong electromagnetic interference, and achieves an overall improvement in the performance of wireless data transmission in complex substation environments.

[0020] The proposed solution has the characteristics of strong adaptability to the complex spatial structure of substations, full utilization of multipath propagation, and high robustness to strong electromagnetic interference. It can effectively improve the data transmission reliability and stability of wireless communication systems in substation environments, and provide an engineering-implementable communication technology solution for wireless monitoring, status perception and intelligent operation of substations. Attached Figure Description

[0021] Figure 1 This is a flowchart of a wireless data transmission method based on the spatial propagation state of a substation, according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the collaborative coding process in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the joint decoding process according to an embodiment of the present invention.

[0024] Figure 4 Box plots showing the received signal-to-noise ratio comparison between the method of the present invention and the comparative method under different obstruction conditions in this embodiment. Detailed Implementation

[0025] To facilitate understanding of the technical solution of the present invention by those skilled in the art, the technical solution of the present invention will now be further described in conjunction with the accompanying drawings.

[0026] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0027] Please see Figure 1 As shown, this invention provides a wireless data transmission method based on the spatial propagation state of a substation, comprising: S10. Based on the spatial distribution structure of primary equipment, secondary equipment and metal frame in the substation, identify several stable propagation states of communication signals formed in the substation space, and construct a set of spatial propagation states of the substation.

[0028] In one embodiment of the present invention, the propagation state variables of the communication node in the substation spatial propagation state set include at least one or more of the following: wireless signal received power, signal-to-noise ratio, bit error rate, and link reachability probability, used to characterize the information transmission state of the communication node under different propagation conditions; wherein, the substation spatial propagation state set is represented as: ; In the formula, The term "spatial propagation state" refers to the set of propagation states in the substation space. Specifically, it can be understood as a set of repeatable, observable wireless signal propagation states induced by the long-term stability of the geometry and electromagnetic characteristics of primary equipment, secondary equipment, and the metal frame, given the substation's spatial structure and equipment layout. This refers to the number of stable spatial propagation states that can be distinguished by measurement or modeling between wireless communication node pairs in the current substation. In the substation space, the first [object] is formed by the combination of specific equipment surface relationships, reflection, diffraction, and propagation constraints. k A stable state of propagation.

[0029] In this embodiment, the evolution of the propagation state variables over time is described by updating the substation spatial propagation state set in a discrete-time manner. The update of the substation spatial propagation state set is based on the propagation state variables at adjacent times and environmental disturbance factors to predict the propagation state at the current time. Among these, the spatial propagation state... Defined as: ; In the formula, This is a set of parameters describing the equivalent spatial propagation trajectory of a wireless signal as it travels from the transmitter to the receiver within a substation, after one or more reflections and diffractions. This is the set of electromagnetic physical property parameters of all propagation media and reflectors related to the propagation state. A set of spatial and structural constraints to limit or stabilize the existence of propagation states.

[0030] In this embodiment, the equivalent spatial propagation trajectory parameters are determined by the relationship between the equipment and space within the substation, and the parameter description set of its equivalent spatial propagation trajectory is... Defined as: ; Electromagnetic physical characteristic parameter set Determined by all propagation media and reflectors along the wireless signal propagation path, it is used to quantitatively characterize the physical modulation effect of primary equipment and metal structure within a substation on wireless signals, and is defined as follows: ; The equivalent reflection coefficient is calculated using the following formula: ; Set of spatial and structural constraints The wireless data transmission constraints are determined by the inherent equipment locations within a given substation, and are defined as follows: ; In the formula, The equivalent length of the propagation path determined by the device geometry. The effective number of reflections and diffractions is determined by the number of surfaces on the equipment. Let be the set of incident angles determined by spatial geometric relations. Let the set of reflection and diffraction angles be determined by the surface normal of the device. The equivalent dielectric constant of the insulating material, The relative permeability of the technical structure, The relative electrical conductivity of the metal surface. The equivalent reflection coefficient, The degree to which the data transmission path is blocked. For data transmission latency, The degree to which the location of the station's inherent equipment is fixed. The equivalent impedance of the device surface. It is the equivalent impedance in the propagation space.

[0031] S20: Based on the set of spatial propagation states in the substation, obtain the wireless signal propagation response corresponding to each propagation state, and calculate the correlation coefficient between different propagation states.

[0032] In one embodiment of the present invention, the wireless signal propagation response corresponding to each propagation state is obtained, expressed by the following formula: ; In the formula, for Time travels through space propagation state Received signal, The set of parameter descriptions for trajectories propagating from the equivalent space The set of parameters of the equivalent spatial propagation trajectory and electromagnetic physical property parameters. The set of dielectric electromagnetic property parameters and spatial and structural constraints in the medium The propagation state equivalent channel response function is determined by the spatial and structural constraints in the equation. The original transmitted signal, Noise signals within a substation, such as those caused by partial discharge, switching operations, and power frequency harmonic modulation.

[0033] The equivalent channel response function of the propagation state is expressed by the following formula: ; In the formula, Let be the propagation state equivalent channel response function. The equivalent reflection coefficient, For the first k Spatial propagation path attenuation factor of a spatial propagation state For the first k The equivalent propagation path length of a spatial propagation state. This is the reference calibration distance within the substation. For delay The Dirac impulse function represents the transient arrival characteristics of an electromagnetic disturbance at the communication receiver after propagation through space. For data transmission latency, The propagation attenuation index is determined by the internal structure of a given substation.

[0034] In this embodiment, the correlation coefficient between different propagation states is calculated using the following method: ; in, ; In the formula, For the first Space propagation state With the Space propagation state The degree of correlation between them The average of the samples is shown in bold. For time window, for Time travels through space propagation state Received signal, for Time travels through space propagation state The received signal.

[0035] S30: Based on the correlation coefficient of the propagation state, the original transmitted wireless data is cooperatively encoded so that the original data information is mapped to multiple spatial propagation states and carried and represented in a correlated manner. With maximizing mutual information constraints as the optimization goal, the effective response between each propagation state and the original signal is achieved during the cooperative coding process.

[0036] Please see Figure 2 As shown, in one embodiment of the present invention, cooperative coding constructs a propagation state correlation matrix based on spatial propagation state correlation, and performs correlation mapping coding on the transmitted data. The coding process is expressed as follows: ; in This represents the mapping of the original signal to the set of spatial propagation states in the substation. Co-coded signal vectors on, The cooperative coding matrix maps the original data to multiple spatial propagation states, and its expression formula is as follows: ; In the formula, For the collaborative coding matrix, In order to make The cooperative coding matrix that yields the minimum value W Values, The Frobenius norm is used to measure the deviation between the actual encoded related structure and the target structure. The spatial propagation state correlation matrix, Let be the target-related constraint matrix, representing the desired propagation state correlation structure under given substation spatial conditions. For real numbers, The number of stable spatial propagation states that can be distinguished by measurement or modeling among wireless communication node pairs in the current substation is shown in bold. Original signal vector Dimensions.

[0037] In this embodiment, the cooperative coding aims to maximize mutual information, and the mutual information constraint is expressed as follows: ; ; In the formula, For mutual information measurement, for Time passes Space propagation state Received signal, For the set of spatial propagation states from the substation The selected subset of propagation states participating in cooperative transmission. The original transmitted signal, For determinant operations, Indicates and Identity matrices of the same dimension This represents the average power of the transmitted signal. This represents the equivalent noise power in a single spatial propagation state. Represents a subset of propagating states The corresponding equivalent propagation state channel response vector or matrix, Represents a subset of spatially propagating states The noise covariance matrix is ​​used to characterize the differences in noise experienced by different propagation states under strong electromagnetic interference conditions in substations. For matrix transpose, For logarithms, For spatial propagation state subset The equivalent noise vector accepted in the process, This is the propagation state equivalent channel response function.

[0038] S40 performs joint decoding on wireless signals from multiple spatial propagation states at the receiving end. By setting the weight vector during the joint decoding process, it ensures the optimal merging selection of multi-path signals and realizes multi-path collaborative data transmission based on the spatial propagation state of the substation.

[0039] Please see Figure 3 As shown, in one embodiment of the present invention, cooperative coding constructs a propagation state correlation matrix based on spatial propagation state correlation, and performs correlation mapping coding on the transmitted data. The coding process is expressed as follows: ; In the joint decoding process, the weight vector achieves optimal merging of multipath signals while considering propagation state correlation and noise characteristics. This is specifically obtained through the following method: ; In the formula, The equivalent received signal recovered after joint decoding. For joint decoding of the weight vector, For matrix transpose, for The signal received at any given time is specifically a received signal vector from multiple spatial propagation states. The covariance matrix of the received signal in multiple propagation states. This is the noise covariance matrix in the electromagnetic environment of a substation, representing the difference in electromagnetic interference intensity under different propagation states. It is the propagation state response vector composed of the equivalent channel responses of each spatial propagation state.

[0040] In one embodiment of the present invention, a wireless signal is transmitted within a substation. After the wireless signal is transmitted through a multipath transmission model of the substation spatial propagation state, an equivalent received signal containing valid information is obtained.

[0041] In one embodiment of the present invention, the invented method is used to perform multi-path coordinated transmission of wireless signals within a specific 220kV substation. The wireless signals originate from non-contact acoustic signature monitoring signals around the main transformer. The primary equipment within the substation includes GIS switchgear, the main transformer, the busbar system, post insulators, and the metal frame. Secondary equipment communication nodes are distributed in the relay protection room, cable trench, and on-site monitoring terminals. In this embodiment, the spatial distribution of the busbars, circuit breakers, and metal frame is modeled. By arranging test transmitters and receivers at different spatial locations, the signal arrival time, received power, and path stability are recorded to identify... M Five main spatial propagation states were identified, and a set of spatial propagation states for substations was constructed. Multiple acoustic signature monitoring signal excitation tests were conducted at the substation site to measure the received signals corresponding to different propagation states. These signals were then time-aligned and power-normalized to obtain the equivalent channel response functions for the five propagation states. By calculating the correlation between the five propagation states, at the transmitting end, based on the propagation state correlation analysis results, a correlation-based cooperative coding method was adopted for the same data, enabling the data to be carried in a correlated manner across multiple propagation states, thereby enhancing the spatial redundancy and anti-interference capability of the information. At the receiving end, joint decoding processing was performed on the received signals from different spatial propagation states. A subset of propagation states was selected from the propagation state set, and the mutual information objective was maximized.

[0042] During field verification, the communication performance of single-path transmission and the multi-propagation state cooperative transmission method of this invention were compared. Table 1 shows the comparison results. Under the same 220kV substation environment and the same communication conditions, compared with the single-path propagation method, the multi-path cooperative wireless data transmission method based on substation spatial propagation state proposed in this invention shows significant improvements in several key communication performance indicators. In the presence of primary equipment metal obstructions and strong electromagnetic interference, the received signal-to-noise ratio (SNR) of the single-path propagation method is typically maintained in the range of 8.1dB-8.6dB, while the equivalent SNR can be increased to 14.9dB-16.2dB after adopting the multi-propagation state cooperative transmission method of this invention, with an average improvement of more than 7dB. Regarding bit error rate (BER), the BER of the single-path propagation method is 4.8%-5.6%, while the method of this invention, through related cooperative coding and multi-propagation state joint decoding, reduces the BER to 0.9%-1.4%, with an average BER reduction of more than 75%. In terms of data transmission efficiency, the effective throughput of single-path propagation is 1.6-2.0 Mbps, while the effective throughput increases to 3.5-4.2 Mbps after adopting multi-propagation mode cooperative transmission, representing an overall improvement of approximately 100%. Regarding successful reception rate, the successful reception rate of single-path propagation is 68%-76%, while the method of this invention, under the cooperative effect of multi-propagation modes, can stably maintain a successful reception rate of 82%-93%, significantly enhancing communication reliability in complex substation environments. In summary, the multi-propagation mode cooperative wireless data transmission method proposed in this invention can effectively improve the signal-to-noise ratio of wireless communication, significantly reduce the bit error rate, and improve data transmission efficiency and stability in substation environments with strong electromagnetic interference and complex metal structures. This verifies the engineering feasibility and technological advancement of the method in practical substation application scenarios.

[0043] Table 1. Performance Comparison Results of Different Wireless Signal Transmission Methods

[0044] Please see Figure 4 The box plots shown compare the received signal-to-noise ratio (SNR) of the proposed method and the comparative method under different obstruction conditions. Under all test conditions, the SNR of the proposed method ranges from 14dB to 16dB, significantly higher than the 8dB to 9dB range of the single-path method. However, as the degree of obstruction increases, the SNR of the single-path method decreases significantly and fluctuates considerably, while the proposed method maintains an SNR of 15dB even under strong obstruction conditions, significantly improving communication reliability. Furthermore, the box plots show that the SNR of the proposed method is more concentrated, with fewer outliers than the single-path method, indicating better robustness in complex electromagnetic environments.

[0045] The present invention also provides a system for applying the above-described wireless data transmission method based on the spatial propagation state of a substation, comprising: The spatial propagation state identification module is used to identify several stable propagation states of communication signals formed in the substation space based on the spatial distribution structure of primary equipment, secondary equipment and metal frame in the substation, and to construct a set of spatial propagation states of the substation.

[0046] The propagation state response modeling module is used to obtain the wireless signal propagation response corresponding to each propagation state based on the spatial propagation state set of the substation, and to calculate the correlation coefficient between different propagation states.

[0047] The cooperative coding module is used to cooperatively code the original transmitted wireless data based on the correlation coefficient of the propagation state, so that the original data information is mapped to multiple spatial propagation states and carried and represented in a correlated manner. With maximizing mutual information constraints as the optimization goal, it realizes the effective response between each propagation state and the original signal during the cooperative coding process.

[0048] The joint decoding module is used to jointly decode wireless signals from multiple spatial propagation states at the receiving end. By setting the weight vector during the joint decoding process, the optimal merging selection of multi-path signals is ensured, thereby realizing multi-path collaborative data transmission based on the spatial propagation state of the substation.

[0049] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0050] The above embodiments are merely examples of implementation methods of the invention. The scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A wireless data transmission method based on substation spatial propagation state, characterized in that, include: Based on the spatial distribution structure of primary equipment, secondary equipment and metal frame in the substation, identify several stable propagation states of communication signals in the substation space and construct a set of substation spatial propagation states. Based on the set of spatial propagation states in the substation, the wireless signal propagation response corresponding to each propagation state is obtained, and the correlation coefficient between different propagation states is calculated. Based on the correlation coefficient of the propagation state, the original transmitted wireless data is co-coded so that the original data information is mapped to multiple spatial propagation states and carried and represented in a correlated manner. With maximizing mutual information constraints as the optimization objective, the effective response between each propagation state and the original signal is achieved during the co-coding process. At the receiving end, wireless signals from multiple spatial propagation states are jointly decoded. By setting the weight vector during the joint decoding process, the optimal merging selection of multi-path signals is ensured, thereby realizing multi-path collaborative data transmission based on the spatial propagation state of the substation.

2. The wireless data transmission method based on substation spatial propagation state according to claim 1, characterized in that, In the substation spatial propagation state set, the propagation state variables of communication nodes include at least one or more of the following: wireless signal received power, signal-to-noise ratio, bit error rate, and link reachability probability, used to characterize the information transmission state of communication nodes under different propagation conditions; wherein, the substation spatial propagation state set is represented as: ； wherein is a set of stable spatial propagation states in the substation space, is the number of stable spatial propagation states between pairs of wireless communication nodes in the substation, which are distinguishable by measurement or modeling, is a stable propagation state in the substation space, which is formed by a specific combination of device surfaces, reflection, diffraction relations and propagation constraints. k ​ 3. The wireless data transmission method based on substation space propagation state according to claim 2, characterized in that, The evolution of the propagation state variable over time is described by a discrete-time update substation spatial propagation state set; the update substation spatial propagation state set predicts the propagation state at the current time based on the propagation state variable at the adjacent time and the environmental disturbance factor; wherein the spatial propagation state is defined as: ； In the formula, is a parameter description set of the equivalent space propagation track formed by one or more reflections and diffractions of the wireless signal in the process from the transmitting end to the receiving end in the substation, is a parameter set of electromagnetic physical characteristics of all propagation media and reflectors related to the propagation state, is a set of spatial and structural constraint conditions for limiting or stabilizing the existence of the propagation state.

4. The wireless data transmission method based on substation space propagation state according to claim 3, characterized in that, The equivalent spatial propagation trajectory parameters are determined by the spatial relationship between the equipment in the substation and the space, and the parameter description set of the equivalent spatial propagation trajectory of the equipment in the substation is defined as: ； A set of electromagnetic physical property parameters Determined by all the propagation media and reflectors passed by the wireless signal propagation path, for quantitatively characterizing the physical modulation effect of the primary equipment and metal structure in the substation on the wireless signal, which is defined as: ； Set of spatial and structural constraints The constraints from wireless data transmission are determined by the location of the equipment inherent in a given substation, which is defined as: ； In the formula, The equivalent length of the propagation path, determined by the device geometry. The effective number of reflections and diffractions is determined by the number of surfaces on the device. Let be the set of incident angles determined by spatial geometric relations. Let the set of reflection and diffraction angles be determined by the surface normal of the device. The equivalent dielectric constant of the insulating material, The relative permeability of the technical structure, The relative electrical conductivity of the metal surface. The equivalent reflection coefficient, The degree to which the data transmission path is blocked. For data transmission latency, The degree to which the location of the station's inherent equipment is fixed.

5. The wireless data transmission method based on substation spatial propagation state according to claim 1, characterized in that, The wireless signal propagation response corresponding to each propagation state is obtained using the following formula: ； In the formula, for Propagation state through space at all times Received signal, The set of parameter descriptions for trajectories propagating from the equivalent space The set of parameters of the equivalent spatial propagation trajectory and electromagnetic physical property parameters in the middle. The set of dielectric electromagnetic property parameters and spatial and structural constraints in the medium The propagation state equivalent channel response function is determined by the spatial and structural constraints in the equation. The original transmitted signal, This refers to noise signals within the substation.

6. The wireless data transmission method based on substation space propagation state according to claim 5, characterized in that, The equivalent channel response function of the propagation state is expressed by the following formula: ； In the formula, Let be the propagation state equivalent channel response function. The equivalent reflection coefficient, For the first k Spatial propagation path attenuation factor of a spatial propagation state For delay The Dirac impulse function, For data transmission latency, The propagation attenuation index is determined by the internal structure of a given substation.

7. The wireless data transmission method based on the spatial propagation state of a substation according to claim 1, characterized in that, The correlation coefficient between different propagation states is calculated using the following method: ； in, ; In the formula, For the first Space propagation state With the Space propagation state The degree of correlation between them The average of the samples is shown in bold. For time window, for Time travels through space propagation state Received signal, for Time travels through space propagation state The received signal.

8. The wireless data transmission method based on substation space propagation state according to claim 1, characterized in that, The original data information is mapped onto multiple spatial propagation states and represented in a correlated manner as follows: ； The constraint for maximizing mutual information is: ； ； In the formula, For the collaborative coding matrix, In order to make The cooperative coding matrix that yields the minimum value W Values, The Frobenius norm is used to measure the deviation between the actual encoded related structure and the target structure. The spatial propagation state correlation matrix, The target-related constraint matrix, For mutual information measurement, for Time passes Space propagation state Received signal, For the set of spatial propagation states from the substation The selected subset of propagation states participating in cooperative transmission. The original transmitted signal, For determinant operations, Indicates and Identity matrices of the same dimension This represents the average power of the transmitted signal. This represents the equivalent noise power in a single spatial propagation state. Represents a subset of propagating states The corresponding equivalent propagation state channel response vector or matrix, Represents a subset of propagating states The noise covariance matrix is ​​used to characterize the differences in noise experienced by different propagation states under strong electromagnetic interference conditions in substations. For matrix transpose, It is a logarithm.

9. The wireless data transmission method based on the spatial propagation state of a substation according to claim 1, characterized in that, At the receiving end, joint decoding of wireless signals from multiple spatial propagation states yields an equivalent received signal as follows: ； The weight vector in the joint decoding process is obtained in the following way: ； In the formula, The equivalent received signal recovered after joint decoding. For joint decoding of the weight vector, For matrix transpose, for The signals received at all times The covariance matrix of the received signal in multiple propagation states. The noise covariance matrix under the electromagnetic environment of the substation. It is the propagation state response vector composed of the equivalent channel responses of each spatial propagation state.

10. A system for applying the method of wireless data transmission based on the spatial propagation state of a substation according to any one of claims 1 to 9, characterized in that, include: The spatial propagation state identification module is used to identify several stable propagation states of communication signals formed in the substation space based on the spatial distribution structure of primary equipment, secondary equipment and metal frame in the substation, and to construct a set of spatial propagation states of the substation. The propagation state response modeling module is used to obtain the wireless signal propagation response corresponding to each propagation state based on the spatial propagation state set of the substation, and to calculate the correlation coefficient between different propagation states. The cooperative coding module is used to cooperatively code the original transmitted wireless data based on the correlation coefficient of the propagation state, so that the original data information is mapped to multiple spatial propagation states and carried and represented in a correlated manner. With maximizing mutual information constraints as the optimization goal, it realizes the effective response between each propagation state and the original signal during the cooperative coding process. The joint decoding module is used to jointly decode wireless signals from multiple spatial propagation states at the receiving end. By setting the weight vector during the joint decoding process, the optimal merging selection of multi-path signals is ensured, thereby realizing multi-path collaborative data transmission based on the spatial propagation state of the substation.

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