Complex environment radio propagation simulation model calculation method based on correction factors

Abstract

The invention discloses a method for calculating a radio propagation simulation model in a complex environment based on correction factors. The system comprises a correction factor calculation module, a complex environment simulation calculation module, a simulation correction module and a simulation data output module. The correction factor calculation module determines a correction factor according to the difference value between the actual measurement value and the simulation value of the corresponding point; the complex environment simulation calculation module performs simulation calculation on each longitude and latitude point according to an existing simulation algorithm; the simulation correction module corrects the simulation value and the correction factor; and the simulation data output module outputs the simulation data according to the matrix. The method has the beneficial effects that the wireless field intensity simulation prediction precision in a complex urban environment is improved, the prediction error of the corrected model in a high-rise building dense area is remarkably reduced, the accuracy of base station layout and signal coverage is effectively improved, and the method can be widely applied to planning and optimization of a wireless communication network and has a wide application prospect. And powerful technical support is provided for improving communication quality.

Description

Technical Field

[0001] The invention relates to the technical field related to radio wave propagation and prediction, and in particular to a method for calculating a radio propagation simulation model in a complex environment based on a correction factor. Background Art

[0002] Radio wave propagation prediction models are crucial in the planning and optimization of wireless communication systems. The ITU-R P.1546-6 model is widely used for terrestrial radio propagation prediction in the frequency range of 30MHz to 4000MHz, and is particularly suitable for base station deployment in complex terrain environments such as cities. However, actual radio wave propagation is often affected by more environmental factors, such as building obstruction, multipath effects, climate change, etc. Although the ITU-R P.1546-6 model has high prediction accuracy, there are still errors in specific scenarios, which may lead to unreasonable base station layout or uneven signal coverage. Summary of the invention

[0003] The present invention aims to overcome the above-mentioned deficiencies in the prior art and provides a method for calculating a radio propagation simulation model in a complex environment based on a correction factor, which can improve the accuracy of base station layout and signal coverage.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] The method for calculating a radio propagation simulation model under a complex environment based on a correction factor comprises a correction factor calculation module, a complex environment simulation calculation module, a simulation correction module, and a simulation data output module; the correction factor calculation module determines the correction factor according to the difference between the actual measurement value and the simulation value of the corresponding point; the complex environment simulation calculation module performs simulation calculation on each longitude and latitude point according to the existing simulation algorithm; the simulation correction module corrects the simulation value and the correction factor; the simulation data output module outputs the simulation data in a matrix; the specific operation steps are as follows:

[0006] (1) The correction factor calculation module compares and calculates the field strength value of the corresponding location of the selected monitoring station with the predicted field strength value of the corresponding location to obtain the corresponding correction factor;

[0007] (2) The complex environment simulation calculation module calculates the simulation field strength at each point in the simulation area based on relevant simulation parameters;

[0008] (3) The simulation correction module corrects the simulated field strength by combining it with the corresponding correction factor, thereby obtaining a simulation result that is closer to the actual value;

[0009] (4) The simulation data output module outputs the final simulation results in a matrix to meet the usage requirements of various applications.

[0010] The present invention provides a method for calculating a radio propagation simulation model in a complex environment based on a correction factor, which improves the accuracy of radio field strength simulation prediction in a complex urban environment. The method first measures the radio signal field strength on site, compares it with the calculation result of the ITU-R P.1546 model, and calculates the difference between the two. Subsequently, based on the data of multiple measurement points, a linear regression method is used to derive the correction factor. The correction factor takes into account key propagation factors such as distance and antenna height, and is applied to the ITU-R P.1546 model, so that the corrected model can more accurately predict the radio wave propagation characteristics in an urban environment. Experimental verification shows that the prediction error of the corrected model in areas with dense high-rise buildings is significantly reduced, effectively improving the accuracy of base station layout and signal coverage. The present invention can be widely used in the planning and optimization of wireless communication networks, providing strong technical support for improving communication quality.

[0011] Preferably, in step (1), the specific calculation process of the correction factor calculation module is as follows:

[0012] (11) Field strength calculation: Based on the ITU-R P.1546-6 model, the theoretical field strength value of the location to be simulated is calculated. The theoretical field strength value is calculated by inputting the base station parameters of the measurement point;

[0013] (12) Field measurement: Use a measuring instrument to measure the actual field strength value of the measuring point at the same location to obtain the real-time signal strength value;

[0014] (13) Difference calculation: Compare the theoretical field strength value calculated based on the ITU-R P.1546 model with the actual measured field strength value to obtain the difference between the two;

[0015] (14) Derivation of correction factor: The correction factor is derived by using the difference data of the positions of each measuring point and the statistical linear regression method.

[0016] Preferably, in step (11), the specific operation of field strength calculation is as follows:

[0017] (111) Select multiple representative measurement points in the urban area, which cover different urban scenes, including high-rise building dense areas, low-rise residential areas, and open streets;

[0018] (112) Based on the standard calculation process of the ITU-R P.1546 model, the base station parameters of the measurement point are input, including antenna height, transmission frequency, receiving antenna height, path length, and time proportion;

[0019] (113) Based on the above input conditions, the ITU-RP.1546 model is used to calculate the theoretical field strength value of each measurement point.

[0020] Preferably, in step (12), the specific operation of the field measurement is as follows:

[0021] (121) Select the measurement site: select an open, unobstructed location and record the precise geographic location of the measurement point to facilitate repeated measurements and comparison of analysis data;

[0022] (122) Set the basic parameters of the measuring instrument, including antenna height, azimuth, and frequency band settings;

[0023] (123) Conduct field measurements and record field strength values, environmental conditions during measurement, and equipment parameters;

[0024] (124) Data recording: Keep a detailed record of each measurement. The table should include the following:

[0025] <time,D,T,H,height,angle,freq_hub>

[0026] Wherein, time indicates the test time, D indicates the actual field strength value, T indicates the temperature, H indicates the humidity, height indicates the antenna height, angle indicates the azimuth, and freq_hub indicates the frequency band.

[0027] Preferably, in step (13), the specific operation of difference calculation is as follows:

[0028] ΔE=E 实测 -E 模型

[0029] Where ΔE represents the prediction error level, E 模型 Indicates the simulation level value, E 实测 Indicates the measured level value.

[0030] Preferably, in step (14), the specific operation of deriving the correction factor is as follows: in order to derive the correction factor suitable for a complex environment, it is necessary to perform a statistical analysis on the field strength difference of multiple measurement points, and use a linear regression method to perform regression fitting on the difference between the predicted value and the measured value to obtain the correction factor, thereby ensuring that the corrected model better adapts to the complex environment; linear regression is a statistical method for determining the optimal parameters by minimizing the sum of squares of prediction errors; the linear regression model can be expressed as: C = a + b·d + c·h2, wherein: C is the correction factor, a, b, c are regression coefficients, d is the distance between the base station antenna and the receiving antenna, and h2 is the height of the receiving antenna; by performing regression analysis on the data of multiple measurement points, the optimal regression coefficients a, b and c are obtained.

[0031] Preferably, in step (2), the complex environment simulation calculation module performs field intensity simulation of the relevant area through relevant parameters, and the specific steps are as follows:

[0032] (21) The propagation path is determined to be land propagation based on the urban environment;

[0033] (22) Determine the nominal time percentage, which is valid only for field strength values ​​that exceed the time percentage in the range of 1% to 50%, and the extrapolation outside the time range of 1% to 50% is invalid; if the required time percentage is between 1% and 10%, the low and high nominal times are 1% and 10% respectively; if the required time percentage is between 10% and 50%, the low and high nominal times are 10% and 50% respectively; when it is equal to 1%, 10% or 50%, the value is directly taken as the low nominal time without interpolation; if the required time percentage does not match the low nominal time, the field strength calculation and interpolation processing are required for the high nominal time;

[0034] (23) Determine the nominal frequency. If the required frequency is lower than 600 MHz, the low-end and high-end nominal frequencies are 100 MHz and 600 MHz respectively. If the required frequency is higher than 600 MHz, the low-end and high-end nominal frequencies are 600 MHz and 2000 MHz respectively. If the required frequency is equal to 100, 600 or 2000 MHz, the value is directly taken as the low-end nominal frequency without interpolation. If the required frequency does not match the low-end nominal frequency, the field strength of the high-end nominal frequency needs to be calculated and interpolated.

[0035] (24) Determine the low-end and high-end nominal distances from the nearest required frequency from the standard values ​​(1-20 km, 20-100 km, 100-200 km, 200-1000 km, with intervals of 1 km, 5 km, 10 km, and 25 km, increasing one by one). If the required distance matches the low-end nominal distance, take this value as the low-end nominal distance without interpolation; if the required distance does not match the low-end nominal distance, calculate the field strength of the high-end nominal distance and perform interpolation processing;

[0036] (25) For the low-end nominal time, the low-end nominal frequency and the nominal distance are processed in turn;

[0037] (26) Based on the required distance and the transmitting / base antenna height h1, obtain the field strength at the exceeding 50% location for the receiving / mobile antenna at the representative clutter height R above the ground;

[0038] (27) Correct the field strength of the terrain clearance angle at the receiving / mobile station by using the frequency and relevant terrain clearance angle information;

[0039] (28) When the receiving / mobile station antenna is in an urban environment, the correction field strength is adjusted according to the received viewing angle;

[0040] (29) Through the above steps, the predicted field strength E is obtained 模型 .

[0041] Preferably, in step (26), only the case where the antenna height is greater than 10m is considered, and the low-end and high-end nominal heights of the antenna height h1 are determined. If they are consistent with the nominal values ​​(10m, 20m, 37.5m, 75m, 150m, 300m, 600m, 1200m), the value is taken as the low-end nominal height without interpolation. If the antenna height h1 does not meet any of the nominal values, the field strength of the high-end nominal distance is calculated and interpolated, and the value is limited to below the maximum value of the free space field strength.

[0042] Preferably, in step (3), the simulation correction module integrates the simulated field strength value and the correction factor to make the simulation more accurate. The specific steps are as follows: applying the derived correction factor to the ITU-R P.1546 model to correct the calculated field strength. The corrected field strength calculation formula is: E 修正 =E 模型 +C; where E 修正 is the corrected field strength value, E 模型 is the field strength value calculated by the ITU-R P.1546 model, and C is the correction factor derived from field measurements.

[0043] The beneficial effects of the present invention are: improving the simulation prediction accuracy of radio field strength in complex urban environments, significantly reducing the prediction error of the revised model in areas with dense high-rise buildings, effectively improving the accuracy of base station layout and signal coverage, and can be widely used in the planning and optimization of wireless communication networks, providing strong technical support for improving communication quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a flowchart of the method of the present invention;

[0045] Figure 2 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0046] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0047] like Figure 1 , Figure 2In the embodiment, the method for calculating the radio propagation simulation model under a complex environment based on the correction factor includes a correction factor calculation module, a complex environment simulation calculation module, a simulation correction module, and a simulation data output module; the correction factor calculation module determines the correction factor according to the difference between the actual measurement value and the simulation value of the corresponding point; the complex environment simulation calculation module performs simulation calculation on each longitude and latitude point according to the existing simulation algorithm; the simulation correction module corrects the simulation value and the correction factor; the simulation data output module outputs the simulation data in a matrix; the specific operation steps are as follows:

[0048] (1) The correction factor calculation module compares and calculates the field strength value of the corresponding location of the selected monitoring station with the predicted field strength value of the corresponding location to obtain the corresponding correction factor;

[0049] The specific calculation process of the correction factor calculation module is as follows:

[0050] (11) Field strength calculation: Based on the ITU-R P.1546-6 model, the theoretical field strength value of the location to be simulated is calculated. The theoretical field strength value is calculated by inputting the base station parameters (such as frequency, antenna height, power, etc.) of the measurement point, as well as the path length, terrain data, etc. The specific operation of the field strength calculation is as follows:

[0051] (111) Select multiple representative measurement points in the urban area, which cover different urban scenes, including

[0052] Areas with dense high-rise buildings: such as high-rise buildings in the city center, which usually produce large multipath effects and building obstructions;

[0053] Low-rise residential areas: such as urban suburbs or residential areas, these areas are relatively open, the building height is low, and the signal propagation path is more direct;

[0054] Open streets: such as main roads or open squares in cities, where signals propagate more freely, but are still affected by reflections from some local buildings.

[0055] (112) Based on the standard calculation process of the ITU-R P.1546 model, the base station parameters of the measurement point are input, including antenna height h1 (e.g., 15 meters), transmission frequency (e.g., 900 MHz), receiving antenna height h2 (e.g., 1.5 meters), path length d (e.g., 2500 meters apart), and time proportion t (e.g., 35%);

[0056] (113) Based on the above input conditions, the ITU-R P.1546 model is used to calculate the theoretical field strength value at each measurement point.

[0057] (12) Field measurement: Use a measuring instrument to measure the actual field strength value of the measurement point at the same location to obtain the real-time signal strength value. The specific operation of field measurement is as follows:

[0058] (121) Select the measurement site: select an open, unobstructed site to ensure that the signal propagation path is minimally affected by reflection, diffraction or attenuation; record the precise geographic location of the measurement point to facilitate repeated measurements and comparison of analysis data;

[0059] (122) Set the basic parameters of the measuring instrument, including

[0060] Antenna height: Set the antenna height as needed to ensure that the antenna height remains constant;

[0061] Azimuth: Adjust the direction of the antenna to ensure that it is pointing in the direction of the signal source and record the direction angle of the antenna;

[0062] Frequency band setting: Select the signal frequency band to be measured and ensure that the device is in the correct frequency range.

[0063] (123) Conduct field measurements,

[0064] Record the field strength value: measure at different time periods and record the field strength value each time in dBμV / m; each measurement should last for several minutes so that the signal can be averaged to obtain a stable field strength value;

[0065] Environmental conditions during measurement: record the weather conditions at the time, including temperature, humidity, wind speed, precipitation, etc.; you can also use relevant meteorological equipment or query meteorological data to record detailed meteorological parameters;

[0066] Equipment parameters: Record all parameters of the equipment during measurement, including antenna height, azimuth, equipment sensitivity settings, spectrum range, etc.

[0067] (124) Data recording: Keep a detailed record of each measurement. The table should include the following:

[0068] <time,D,T,H,height,angle,freq_hub>

[0069] Where time indicates the test time, D indicates the actual field strength value (dBμV / m), T indicates the temperature, H indicates the humidity, height indicates the antenna height, angle indicates the azimuth, and freq_hub indicates the frequency band.

[0070] (13) Difference calculation: Compare the theoretical field strength value calculated based on the ITU-R P.1546 model with the actual measured field strength value to obtain the difference between the two; the difference reflects the prediction error of the model at this location. The specific operation of the difference calculation is as follows:

[0071] ΔE=E 实测 -E 模型

[0072] Where ΔE represents the prediction error level, E 模型 Indicates the simulation level value, E 实测 Indicates the measured level value.

[0073] (14) Derivation of correction factor: The correction factor is derived by using the difference data of the positions of each measuring point and the statistical linear regression method.

[0074] The specific operations for deriving the correction factors are as follows: In order to derive the correction factors suitable for complex environments, it is necessary to conduct statistical analysis on the field strength differences at multiple measurement points, and use the linear regression method to regress and fit the differences between the predicted values ​​and the measured values ​​to obtain the correction factors, thereby ensuring that the corrected model better adapts to the propagation environment in the city.

[0075] Linear regression is a statistical method for determining the optimal parameters by minimizing the sum of squares of prediction errors. In the present invention, linear regression is used to derive the correction factor so that the error between the field strength value predicted by the model and the measured field strength value is minimized.

[0076] The linear regression model can be expressed as: C = a + b·d + c·h2,

[0077] Where: C is the correction factor, a, b, c are regression coefficients, d is the distance between the base station antenna and the receiving antenna (i.e., the path length), and h2 is the height of the receiving antenna.

[0078] By performing regression analysis on the data of multiple measurement points, the optimal regression coefficients a, b and c can be obtained. These coefficients reflect the influence of factors such as distance and antenna height on the model prediction error. This method can quantify the influence of multipath effect and building shielding on radio wave propagation in urban environments, thus providing a basis for model correction.

[0079] (2) The complex environment simulation calculation module calculates the simulated field strength at each point in the simulation area according to the relevant simulation parameters; the complex environment simulation calculation module simulates the field strength of the relevant area through the relevant parameters, and the specific steps are as follows:

[0080] (21) The propagation path is determined to be land propagation based on the urban environment;

[0081] (22) The nominal time percentage is determined only for field strength values ​​exceeding the time percentage in the range 1% to 50%. Extrapolation outside the time range 1% to 50% is invalid.

[0082] If the required time percentage is between 1% and 10%, the low-end and high-end nominal times are 1% and 10% respectively;

[0083] If the required time percentage is between 10% and 50%, the low-end and high-end nominal times are 10% and 50% respectively;

[0084] When it is equal to 1%, 10% or 50%, the value is directly taken as the low-end nominal time without interpolation;

[0085] If the required time percentage does not match the low-end nominal time, the field strength calculation for the high-end nominal time must be performed and interpolated according to the following formula; the formula is as follows:

[0086]

[0087] in:

[0088] t: the time percentage for which the field strength prediction needs to be output;

[0089] t inf : The lower limit of the time percentage;

[0090] t sup : Upper limit of time percentage;

[0091] Q t : The current time percentage fraction, defined as Q t =Q(t / 100);

[0092] Q inf : The lower limit time percentage fraction, defined as Q inf =Q(t inf / 100);

[0093] Q sup : Upper limit time percentage fraction, defined as Q sup =Q(t sup / 100);

[0094] E inf : Field strength value corresponding to the lower limit time percentage fraction;

[0095] E sup : Field strength value corresponding to the upper limit time percentage fraction.

[0096] (23) Determine the nominal frequency,

[0097] If the required frequency is less than 600MHz, the low-end and high-end nominal frequencies are 100MHz and 600MHz respectively;

[0098] If the required frequency is higher than 600MHz, the low-end and high-end nominal frequencies are 600MHz and 2000MHz respectively;

[0099] When it is equal to 100, 600 or 2000 MHz, directly take this value as the low-end nominal frequency without interpolation;

[0100] If the required frequency does not match the low-end nominal frequency, the field strength calculation for the high-end nominal frequency must be performed and interpolated according to the following formula; the formula is as follows:

[0101]

[0102] in:

[0103] f: frequency for which field strength prediction is required (MHz);

[0104] f inf : Low-end nominal frequency (100MHz when f<600MHz, otherwise 600MHz);

[0105] f sup : High-end nominal frequency (600MHz when f<600MHz, otherwise 600MHz);

[0106] E inf :f inf The field strength value of

[0107] E sup :f sup The field strength value.

[0108] (24) Determine the low-end and high-end nominal distances from the nearest required frequency from the standard values ​​(1-20 km, 20-100 km, 100-200 km, 200-1000 km, with intervals of 1 km, 5 km, 10 km, 25 km, increasing one by one). If the required distance matches the low-end nominal distance, take this value as the low-end nominal distance without interpolation; if the required distance does not match the low-end nominal distance, calculate the field strength of the high-end nominal distance and interpolate according to the following formula; the formula is as follows:

[0109]

[0110] in:

[0111] d: distance for which field strength prediction is required;

[0112] d inf : The closest distance among the scalar values ​​that is less than d;

[0113] d sup : The closest distance among the labeled values ​​that is greater than d;

[0114] E inf :d inf The field strength value at

[0115] E sup :d sup The field strength value at .

[0116] (25) For the low-end nominal time, the low-end nominal frequency and the nominal distance are processed in turn;

[0117] (26) Based on the required distance and the transmitting / base antenna height h1, obtain the field strength at the exceeding 50% location for the receiving / mobile antenna at the representative clutter height R above the ground;

[0118] Only consider the case where the antenna height is greater than 10m, determine the low-end and high-end nominal heights of the antenna height h1. If it matches the nominal value (10m, 20m, 37.5m, 75m, 150m, 300m, 600m, 1200m), then this value is taken as the low-end nominal height without interpolation;

[0119] If the antenna height h1 does not meet any of the nominal values, the field strength is calculated for the high-end nominal distance and interpolated according to the following formula, and the value is limited to below the maximum value of the free space field strength. The formula is as follows:

[0120]

[0121] in:

[0122] h inf :If h1>1 200m, then h inf =600m; otherwise, h inf Take the nearest nominal effective height below h1;

[0123] h sup :If h1>1 200m, then h sup =1200m; otherwise, h sup Take the nearest nominal effective height above h1;

[0124] E inf : at the required distance h inf The field strength value of

[0125] E sup : at the required distance h sup The field strength value.

[0126] (27) The field strength of the terrain clearance angle is corrected at the receiving / mobile station using the frequency and relevant terrain clearance angle information according to the following method; the formula is as follows:

[0127]

[0128] in:

[0129] θ tca : is the terrain clearance angle (degrees);

[0130] f: frequency (MHz).

[0131] (28) When the receiving / mobile station antenna is in an urban environment, the correction field strength is adjusted according to the received viewing angle. First, the representative scattering height R needs to be corrected (the default reference height is 15 m in urban areas, 20 m in dense urban areas, and 10 m in suburban areas). The formula is:

[0132] R′=(1000dR-15h2) / (1000d-15h2)m

[0133] in:

[0134] d: distance between receiving antenna and transmitting antenna (Km);

[0135] h2: Height of the receiving antenna.

[0136] When the receiving antenna height h2 is less than R′,

[0137]

[0138] When the receiving antenna height h2 is greater than or equal to R′,

[0139]

[0140] in:

[0141]

[0142] h dif2 =R′-h2;

[0143] θ clut2 =arctan(h dif2 / 27) degree;

[0144]

[0145] f: frequency (MHz).

[0146] (29) Through the above steps, the predicted field strength E is obtained 模型 .

[0147] (3) The simulation correction module corrects the simulated field strength by combining it with the corresponding correction factor, thereby obtaining a simulation result that is closer to the actual value; the simulation correction module merges the simulated field strength value and the correction factor to make the simulation more accurate. The specific steps are as follows:

[0148] The derived correction factor is applied to the ITU-R P.1546 model to correct the calculated field strength. The corrected field strength calculation formula is: E 修正 =E 模型 +C;

[0149] in:

[0150] E 修正 is the corrected field strength value,

[0151] E 模型 The field strength values ​​calculated for the ITU-R P.1546 model,

[0152] C is the correction factor derived from field measurements.

[0153] This correction process can more closely combine the simulation field strength prediction results with the propagation characteristics of the actual urban environment, thereby improving the prediction accuracy of the model.

[0154] (4) The simulation data output module outputs the final simulation results in a matrix to meet the usage requirements of various applications.

[0155] In a complex urban environment, the propagation of radio waves is affected by many factors, such as building obstruction, multipath effect, reflection and signal attenuation. In order to improve the prediction accuracy of the ITU-R P.1546 model in an urban environment, the present invention derives a correction factor suitable for an urban environment through the difference between field measurements and calculations, and applies it to the model. The specific implementation examples are as follows:

[0156] First, representative measurement points (such as high-rise building areas, low-rise residential areas, and open streets) are selected in a complex urban environment through the correction factor calculation module. The radio field strength at these locations is measured on the spot, and base station parameters such as transmission frequency, antenna height, and path length are recorded. Then, the measured field strength value is compared with the theoretical field strength value calculated by the ITU-R P.1546 model to calculate the field strength difference. Based on the data of multiple measurement points, the correction factor C = a + b·d + c·h is derived using the linear regression method, where a, b, and c are regression coefficients, and the table is a = 24, b = -22, c = 0.47, d is the distance between the base station and the receiving antenna (path length), and h2 is the height of the receiving antenna.

[0157] Next, in the complex environment simulation calculation module, based on the standard calculation process of the ITU-R P.1546 model and combined with the base station parameters provided by the correction factor calculation module, the field strength simulation is performed for each point in the target area. This module can handle factors such as multipath effects and building obstructions in complex environments, and calculate the initial simulated field strength value of radio wave propagation through a sophisticated simulation algorithm.

[0158] Then, through the simulation correction module, the correction factor is applied to the initial simulation field strength value for accurate correction. The calculation formula for the corrected field strength value is:

[0159] E 修正 =E 模型 +C

[0160] Where: E 修正 is the corrected field strength value, E 模型 is the initial field strength value calculated in the ITU-R P.1546 model, and C is the correction factor. Through this module, the simulation results will be closer to the actual measured values ​​and reduce the prediction error.

[0161] Finally, the corrected simulation results will be output through the simulation data output module. The output data is usually presented in matrix form, including the corrected field strength value of each measurement point.

[0162] At this point, a calculation method for radio propagation simulation model in complex environment based on correction factor is completed.

[0163] After experimental calculation, the present invention uses the verification correction factor to apply the revised ITU-R P.1546 model to the same or similar urban environment for field strength prediction, and compares it with the actual measurement results again. The experiment shows that the revised model can significantly reduce the error, especially in high-rise building dense areas, the gap between the predicted results and the measured values ​​is reduced by more than 30%. In addition, in low-rise building areas and open street areas, the correction effect of the model has also been verified, and the predicted field strength value is closer to the measured data. With this revised model, the deployment and network optimization of base stations in cities will be more efficient. The layout of base stations can be adjusted according to more accurate propagation predictions to reduce signal blind spots and improve the user's communication experience.

Claims

1. A calculation method for radio propagation simulation model in complex environment based on correction factors, characterized in that: It includes a correction factor calculation module, a complex environment simulation calculation module, a simulation correction module, and a simulation data output module; The correction factor calculation module determines the correction factor according to the difference between the actual measurement value and the simulation value of the corresponding point; The complex environment simulation calculation module performs simulation calculation on each latitude and longitude point according to the existing simulation algorithm; the simulation correction module corrects the simulation value and the correction factor; the simulation data output module outputs the simulation data in a matrix; the specific operation steps are as follows: (1) The correction factor calculation module compares and calculates the field strength value of the corresponding location of the selected monitoring station with the predicted field strength value of the corresponding location to obtain the corresponding correction factor; (2) The complex environment simulation calculation module calculates the simulation field strength at each point in the simulation area based on relevant simulation parameters; (3) The simulation correction module corrects the simulated field strength by combining it with the corresponding correction factor, thereby obtaining a simulation result that is closer to the actual value; (4) The simulation data output module outputs the final simulation results in a matrix to meet the usage requirements of various applications.

2. The method for calculating a radio propagation simulation model under a complex environment based on correction factors according to claim 1 is characterized in that: In step (1), the specific calculation process of the correction factor calculation module is as follows: (11) Field strength calculation: Based on the ITU-R P.1546-6 model, the theoretical field strength value of the location to be simulated is calculated. The theoretical field strength value is calculated by inputting the base station parameters of the measurement point; (12) Field measurement: Use a measuring instrument to measure the actual field strength value of the measuring point at the same location to obtain the real-time signal strength value; (13) Difference calculation: Compare the theoretical field strength value calculated based on the ITU-R P.1546 model with the actual measured field strength value to obtain the difference between the two; (14) Derivation of correction factor: The correction factor is derived by using the difference data of the positions of each measuring point and the statistical linear regression method.

3. The method for calculating a radio propagation simulation model under a complex environment based on correction factors according to claim 2 is characterized in that: In step (11), the specific operation of field strength calculation is as follows: (111) Select multiple representative measurement points in the urban area, which cover different urban scenes, including high-rise building dense areas, low-rise residential areas, and open streets; (112) Based on the standard calculation process of the ITU-R P.1546 model, the base station parameters of the measurement point are input, including antenna height, transmission frequency, receiving antenna height, path length, and time proportion; (113) Based on the above input conditions, the ITU-R P.1546 model is used to calculate the theoretical field strength value at each measurement point.

4. The method for calculating a radio propagation simulation model under a complex environment based on correction factors according to claim 2 is characterized in that: In step (12), the specific operation of field measurement is as follows: (121) Select the measurement site: select an open, unobstructed location and record the precise geographic location of the measurement point to facilitate repeated measurements and comparison of analysis data; (122) Set the basic parameters of the measuring instrument, including antenna height, azimuth, and frequency band settings; (123) Conduct field measurements and record field strength values, environmental conditions during measurement, and equipment parameters; (124) Data recording: Keep a detailed record of each measurement. The table should include the following: <time,D,T,H,height,angle,freq_hub> Wherein, time indicates the test time, D indicates the actual field strength value, T indicates the temperature, and H indicates the humidity. height represents the antenna height, angle represents the azimuth, and freq_hub represents the frequency band.

5. The method for calculating a radio propagation simulation model under a complex environment based on correction factors according to claim 2 is characterized in that: In step (13), the specific operation of difference calculation is as follows: ΔE=E 实测 -E 模型 Where ΔE represents the prediction error level, E 模型 Indicates the simulation level value, E 实测 Indicates the measured level value.

6. The method for calculating a radio propagation simulation model under a complex environment based on correction factors according to claim 2 is characterized in that: In step (14), the specific operation of deriving the correction factor is as follows: In order to derive the correction factor suitable for a complex environment, it is necessary to perform a statistical analysis on the field strength difference of multiple measurement points, and use a linear regression method to perform regression fitting on the difference between the predicted value and the measured value to obtain the correction factor, so as to ensure that the corrected model is better adapted to the complex environment; Linear regression is a statistical method that determines the optimal parameters by minimizing the sum of squared prediction errors; The linear regression model can be expressed as: C = a + b·d + c·h2, where: C is the correction factor, a, b, c are regression coefficients, d is the distance between the base station antenna and the receiving antenna, and h2 is the height of the receiving antenna; by performing regression analysis on the data of multiple measurement points, the optimal regression coefficients a, b and c are obtained.

7. The method for calculating a radio propagation simulation model under a complex environment based on correction factors according to claim 1 is characterized in that: In step (2), the complex environment simulation calculation module simulates the field strength of the relevant area through relevant parameters, and the specific steps are as follows: (21) The propagation path is determined to be land propagation based on the urban environment; (22) Determine the nominal time percentage, which is valid only for field strength values ​​that exceed the time percentage in the range of 1% to 50%, and the extrapolation outside the time range of 1% to 50% is invalid; if the required time percentage is between 1% and 10%, the low and high nominal times are 1% and 10% respectively; if the required time percentage is between 10% and 50%, the low and high nominal times are 10% and 50% respectively; when it is equal to 1%, 10% or 50%, the value is directly taken as the low nominal time without interpolation; if the required time percentage does not match the low nominal time, the field strength calculation and interpolation processing are required for the high nominal time; (23) Determine the nominal frequency. If the required frequency is lower than 600 MHz, the low-end and high-end nominal frequencies are 100 MHz and 600 MHz respectively. If the required frequency is higher than 600 MHz, the low-end and high-end nominal frequencies are 600 MHz and 2000 MHz respectively. If the required frequency is equal to 100, 600 or 2000 MHz, the value is directly taken as the low-end nominal frequency without interpolation. If the required frequency does not match the low-end nominal frequency, the field strength of the high-end nominal frequency needs to be calculated and interpolated. (24) Determine the low-end and high-end nominal distances from the nearest required frequency from the standard values ​​(1-20 km, 20-100 km, 100-200 km, 200-1000 km, with intervals of 1 km, 5 km, 10 km, and 25 km, increasing one by one). If the required distance matches the low-end nominal distance, take this value as the low-end nominal distance without interpolation; if the required distance does not match the low-end nominal distance, calculate the field strength of the high-end nominal distance and perform interpolation processing; (25) For the low-end nominal time, the low-end nominal frequency and the nominal distance are processed in turn; (26) Based on the required distance and the transmitting / base antenna height h1, obtain the field strength at the exceeding 50% location for the receiving / mobile antenna at the representative clutter height R above the ground; (27) Correct the field strength of the terrain clearance angle at the receiving / mobile station by using the frequency and relevant terrain clearance angle information; (28) When the receiving / mobile station antenna is in an urban environment, the correction field strength is adjusted according to the received viewing angle; (29) Through the above steps, the predicted field strength E is obtained 模型 .

8. The method for calculating a radio propagation simulation model under a complex environment based on correction factors according to claim 7 is characterized in that: In step (26), only the case where the antenna height is greater than 10m is considered, and the low-end and high-end nominal heights of the antenna height h1 are determined. If they are consistent with the nominal values ​​(10m, 20m, 37.5m, 75m, 150m, 300m, 600m, 1200m), then this value is taken as the low-end nominal height without interpolation. If the antenna height h1 does not meet any of the nominal values, the field strength of the high-end nominal distance is calculated and interpolated, and the value is limited to below the maximum value of the free space field strength.

9. The method for calculating a radio propagation simulation model under a complex environment based on correction factors according to claim 8 is characterized in that: In step (3), the simulation correction module combines the simulated field strength value and the correction factor to make the simulation more accurate. The specific steps are as follows: Apply the derived correction factor to the ITU-RP.1546 model to correct the calculated field strength. The corrected field strength calculation formula is: E 修正 =E 模型 +C; Among them, E 修正 is the corrected field strength value, E 模型 is the field strength value calculated by the ITU-R P.1546 model, and C is the correction factor derived from field measurements.

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