Base station site selection method based on space optimization algorithm and actually measured signal model calibration

Abstract

The invention provides a base station site selection method based on a space optimization algorithm and actually measured signal model calibration, which comprises the following steps: step 1, determining a central point and a radius of a signal weak coverage to-be-promoted area, and calculating a distance between a target base station planning point and a weak coverage central point according to a signal propagation model; 2, setting a search radius by taking the center of the signal weak coverage to-be-promoted area as a circle center, determining a circular search circle according to the search radius, and obtaining the total number of base stations in the search circle and an initial disordered base station list; step 3, when the total number of the base stations in the search circle is 1, obtaining a target base station planning point coordinate; and step 4, when the total number of the base stations in the search circle is greater than 1, optimizing the spatial ordering of the base stations, and calculating the planning point coordinates of the target base station. According to the method, the actually measured signal data is combined, the signal weak coverage to-be-promoted area is precisely oriented, the site selection precision is improved, it is ensured that base station deployment can effectively cover the target area, the site selection precision is improved, and the result consistency is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communications, and in particular relates to a base station site selection method based on a space optimization algorithm and measured signal model calibration. Background Art

[0002] There are two main types of base station site selection methods in the prior art:

[0003] (1) Site selection method based on experience and manual survey. This method mainly relies on the experience and on-site survey of engineers to determine the base station location. Engineers will select a suitable base station location based on factors such as topography, population density, building distribution, and existing base station coverage.

[0004] (2) Site selection method based on simulation. This method first generates several candidate base stations, and then uses professional wireless propagation simulation software to establish a wireless propagation model based on existing terrain data, building data, population density data, etc., to simulate the signal coverage under different base station locations. By adjusting the base station location and parameters, the best site selection solution is found.

[0005] The methods of the prior art have the following problems:

[0006] (1) Low site selection accuracy: The site selection method based on experience and manual survey relies on the experience of engineers for its accuracy. It usually requires multiple on-site surveys and adjustments, is highly subjective, and it is difficult to ensure the consistency of the plan.

[0007] (2) Low efficiency of site selection: The site selection method based on simulation requires a large amount of input data and has high requirements on data quality. In addition, the simulation software is expensive, the modeling and simulation process is complex and time-consuming, and the amount of calculation is large. Summary of the invention

[0008] Purpose of the invention: The technical problem to be solved by the present invention is to provide a base station site selection method based on spatial optimization algorithm and measured signal model calibration in view of the shortcomings of the prior art. The core idea of ​​the method of the present invention is to directly solve a global optimal base station location by utilizing the maximum spatial geometry optimization algorithm model and combining the measured signal data, so as to directly determine an optimal base station layout plan for the area with weak signal coverage to be improved.

[0009] The method of the present invention comprises the following steps:

[0010] Step 1: determine the center point and radius of the area with weak signal coverage to be improved, measure the field strength value and main service cell number of the center point of weak signal coverage, set the target field strength value of the area with weak signal coverage to be improved, and calculate the distance between the target base station planning point and the center point of weak coverage according to the signal propagation model;

[0011] Step 2: Set the search radius with the center of the area with weak signal coverage to be improved as the center, determine the circular search circle with the search radius, and obtain the total number of base stations in the search circle and the initial unordered base station list;

[0012] Step 3: When the total number of base stations in the search circle is 1, the coordinates of the target base station planning point are directly obtained according to the vector extension ratio principle;

[0013] Step 4: When the total number of base stations in the search circle is greater than 1, optimize the spatial sorting of the base stations and calculate the coordinates of the target base station planning point through the maximum spatial geometry algorithm.

[0014] Step 1 includes: setting O(x0, y0) as the center point of the area with weak signal coverage to be improved, E s is the initial field strength value at point O(x0,y0), C ID is the primary serving base station cell number of point O(x0,y0);

[0015] The cell number is C. ID The main service base station, assuming the coordinates of the main service base station are A s (x s ,y s ), according to the distance formula between two points, the distance between point O(x0,y0) and the main service base station A is obtained s (x s ,y s ) is D s ;

[0016] Assume E t is the target field strength value at point O(x0,y0), D t The field strength is E t The distance between the time point O(x0,y0) and the corresponding primary serving base station cell.

[0017] In step 1, according to the free space loss formula: Lbs = 32.45 + 20lgF + 20lgD, where Lbs represents the total propagation loss; F represents the frequency; and D represents the propagation distance.

[0018] When the propagation distance is given by D s Change to D t The propagation loss change value Δ Lbs for:

[0019] Δ Lbs =20lgD s -20lgD t ;

[0020] Consider E t 、E s If is a negative number, then:

[0021] ΔLbs =E s -E t ;

[0022] Find D t The values ​​are:

[0023]

[0024] In step 1, let r be the radius of the area where signal weak coverage is to be improved. Then the distance L between the target base station planning point and the weak coverage center point O(x0, y0) must satisfy L = D t -r, the formula is:

[0025]

[0026] Step 2 includes: setting R as the search radius, λ as the total number of base stations in the circular search circle with a radius of R; since the center of the area with weak signal coverage to be improved has received the signal of the main service base station, the main service base station A s (x s ,y s ) must be in the list of λ base stations in the search circle, λ satisfies the condition λ≥1, and when setting R, the condition R≥D must be satisfied s ;

[0027] Take point O(x0,y0) as the center and R as the radius to obtain the list of surrounding λ base stations A1(x1,y1), A2(x2,y2), A i (x i ,y i ),……、A λ (x λ ,y λ ), that is, A i (x i ,y i ) is represented as any point on the list, and the list of surrounding λ base stations is the initial unordered base station list, recorded as {A i (x i ,y i )},i∈[1,λ].

[0028] Step 3 includes: when λ=1, it means that there is only one base station in the search circle set in step 2, and the base station is the main service base station A of the center O(x0, y0) of the area to be improved with weak signal coverage s (x s ,y s );

[0029] Assume the coordinates of the target base station planning point are T(x t ,y t ), if the geometric angle in the search circle is optimal, then point T(x t,y t ) must be in On the extension line of t ,y t ) and O(x0,y0) is L obtained in step 1;

[0030] According to the vector ratio principle, vector and Satisfaction between

[0031]

[0032] Then we can obtain T(x t ,y t ), where:

[0033]

[0034] Step 4 includes:

[0035] Step 4-1, sort the initial unordered base station list obtained in step 2 in a counterclockwise direction and renumber it to form an ordered base station list:

[0036] In the plane rectangular coordinate system, let W(x0+1,y0) be a point on the positive half axis of the horizontal X-axis with O(x0,y0) as the origin, then ∠A i OW represents vector and If ∠A is used i The size of OW represents point A i (x i ,y i ) in counterclockwise order with O(x0,y0) as the center, then point A below the X axis needs to be i (x i ,y i ) and O(x0,y0) and The range of the angle value is converted to (π, 2π);

[0037] It is represented as (1,0), It is expressed as (x i -x0,y i -y0), according to the vector angle formula Calculate each A according to the following formula i (x i ,y i ) corresponds to ∠A i OW size:

[0038] When iWhen y ≥ y0,

[0039] When y i < y0,

[0040] Next, according to the ∠A i OW value, re - sort the initial unordered base station list {A i (x i , y i )}, i ∈ [1, λ] in ascending order, and the sorted ordered base station list is A1(x1, y1), A2(x2, y2), A j (x j , y j ), ……, A λ (x λ , y λ ), denoted as {A j (x j , y j )}, j ∈ [1, λ];

[0041] Step 4 - 2: Calculate the included angles between the coordinates of any two adjacent base stations in the ordered base station list and the center of the signal weak - coverage area to be improved, compare to obtain the maximum included angle, and record the coordinates of the two base stations that form the maximum included angle at the same time;

[0042] Step 4 - 3: According to the principle of the in - center formula of a triangle, obtain the equation of the straight line where the angle bisector of the maximum included angle in Step 4 - 2 is located;

[0043] Step 4 - 4: Based on the straight - line equation and the distance between two points, construct a binary linear equation and solve for the coordinates of two sets of target base - station planning points;

[0044] Step 4 - 5: Based on the optimal algorithm of spatial geometric angles, select the coordinates of the target base - station planning point that forms a larger angle with the weak - coverage center point and the main - serving base - station cell.

[0045] Step 4 - 2 includes: Let A j (x j , y j ) be any point in the ordered base station list {A j (x j , y j )}, j ∈ [1, λ] obtained in Step 4, then the adjacent point of point A j (x j , y j ) is:

[0046] When j = 1, the adjacent point of A1(x1, y1) is A2(x2, y2) and A λ (x λ , yλ );

[0047] When 1 < j < λ, A j (x j , y j )'s adjacent points are A j-1 (x j-1 , y j-1 ) and A j+1 (x j+1 , y j+1 );

[0048] When j = λ, A λ (x λ , y λ )'s adjacent points are A λ-1 (x λ-1 , y λ-1 ) and A1(x1, y1);

[0049] Therefore, there are a total of λ included angle values between the coordinates of all adjacent base stations in the ordered base station list {A j (x j , y j ), j ∈ [1, λ]} and the point O(x0, y0). The calculation formula is:

[0050] When 1 ≤ j < λ,

[0051]

[0052] When j = λ,

[0053]

[0054] Among the obtained λ angles, compare to get a maximum angle, record the coordinates of the two base stations that form the maximum angle, and assume the coordinates of the two base stations are A m (x m , y m ), A n (x n , y n ), then the maximum included angle is ∠A m OA n .

[0055] Step 4 - 3 includes: The point O(x0, y0) is the center of the area with weak signal coverage to be improved. The points A m (x m , y m ), A n (x n , y n ) and O(x0, y0) form the maximum angle ∠A m OA n, and point A m (x m ,y m ), A n (x n ,y n ) and O(x0,y0) directly form a triangle ΔA m OA n ; Through O(x0,y0), A m (x m ,y m ), A n (x n ,y n ) The coordinates of the three points give the triangle ΔA m OA n The three side lengths are:

[0056]

[0057] Let P(x p ,y p ) is a triangle A m OA n The inner heart is obtained by the inner heart formula:

[0058]

[0059]

[0060] Triangle ∠A m OA n The straight line on which the angle bisector of p ,y p ), then the equation of the angle bisector OP is Convert the equation to standard straight line form:

[0061] y=kx+l,

[0062] The slope Intercept l = x p y0-x0y p .

[0063] Step 4-4 includes: assuming that the coordinates of the target base station planning point are T(x t ,y t ), if the geometric angle in the search circle is optimal, then point T(x t ,y t ) must be on the straight line equation obtained in step 4-3, and T(x t ,y t ) is L obtained in step 1, then the coordinate xt ,y t Satisfies the following formula:

[0064] y t =kx t +l

[0065] (x t -x0) 2 +(y t -y0) 2 =L 2

[0066] Convert to a standard linear equation in two variables:

[0067] ax t 2 +bx t +c=0,

[0068] in,

[0069] Intermediate parameter a = k 2 +l,

[0070] The intermediate parameter b = 2kl-2ky0-2x0,

[0071] Intermediate parameter c = x0 2 +(l-y0) 2 -L 2 ;

[0072] Assume that the coordinates of the target base station planning points are T(x t ,y t )、T'(x t ',y t '), the solutions are:

[0073]

[0074] The coordinates of the two points T(x t ,y t )、T'(x t ',y t '), a point is located at ∠A m OA n The other point is on the angle bisector of ∠A m OA n On the extension of the angle bisector of ;

[0075] Step 4-5 includes: respectively calculating the two groups of target base station planning points and the center of the weak signal coverage area to be improved O(x0, y0) and the main service base station A in step 4-4 s (x s ,y s ), that is, calculate ∠As OT, ∠A s OT', the formula is:

[0076]

[0077] When ∠A s OT>∠A s OT', the target base station planning point coordinates are selected as T(x t ,y t ),

[0078] When ∠A s OT<∠A s OT', the target base station planning point coordinates are selected as T'(x t ',y t ');

[0079] When ∠A s OT=∠A s OT', from T(x t ,y t )、T'(x t ',y t ') to select any point.

[0080] The present invention has the following beneficial effects: (1) Improving site selection accuracy: By combining the measured signal data, the site selection accuracy is improved by accurately targeting the area with weak signal coverage to be improved, ensuring that the base station deployment can effectively cover the target area, improving the site selection accuracy, and ensuring the consistency of the results.

[0081] (2) Improve site selection efficiency: The maximum spatial geometry optimization algorithm is used to directly solve the optimal base station location without relying on a large amount of input data, avoiding the complex calculations in the modeling process and significantly improving site selection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0083] Figure 1 This is a diagram showing the calculation principle of the distance between the target base station planning point and the weak coverage center.

[0084] Figure 2 It is a distribution map of the unordered list of base stations within the search circle filtered by radius.

[0085] Figure 3 This is a calculation diagram of the target base station planning point when there is only a single base station in the search circle.

[0086] Figure 4 It is a schematic diagram of an ordered list of base stations sorted by a spatial algorithm.

[0087] Figure 5 This is a calculation principle diagram for finding the target base station planning point based on the angle bisector principle. DETAILED DESCRIPTION

[0088] This embodiment proposes a base station site selection method based on a spatial optimization algorithm and measured signal model calibration, which specifically includes the following steps:

[0089] Step 1: Determine the center point and radius of the area with weak signal coverage to be improved, measure the field strength value and main service cell number of the center point of weak coverage, set the target field strength value of the area with weak signal coverage to be improved, and calculate the distance between the target base station planning point and the center point of weak coverage according to the signal propagation model.

[0090] like Figure 1 As shown in the figure, O(x0,y0) is the center point of the area with weak signal coverage to be improved, E s is the initial field strength value at point O(x0,y0), C ID is the cell number of the main service base station at point O(x0,y0). According to the operator's artificial parameter information table, the cell number can be found to be C ID The main service base station, assuming that the coordinates of the main service base station are A s (x s ,y s ), according to the distance formula between two points, we can get the distance between point O(x0,y0) and its main service base station A s (x s ,y s ) is D s . Let E t is the target field strength value at point O(x0,y0), D t The field strength is E t The distance between the time point O(x0,y0) and its corresponding primary serving base station cell.

[0091] This embodiment takes the free space propagation model in the signal propagation model as an example, according to the free space loss formula: Lbs=32.45+20lgF+20lgD, where Lbs represents the total propagation loss, F represents the frequency, and D represents the propagation distance in km.

[0092] From this formula, we can see that when the frequency F remains unchanged, the only factor affecting the propagation loss is the propagation distance D. Therefore, we can find that when the propagation distance is D s Change to D t The propagation loss change value Δ Lbs for:

[0093] Δ Lbs =20lgD s -20lgD t .

[0094] Because Δ Lbs Equal to E t and E s The difference between the two, considering E t 、E s If is a negative number, then:

[0095] Δ Lbs =E s -E t .

[0096] Based on the above Δ Lbs The two formulas of D can be obtained t The values ​​are:

[0097]

[0098] Since the target base station construction needs to consider the entire area with weak signal coverage to be improved, rather than just the center point of weak coverage. Assuming the radius of the area with weak signal coverage to be improved is r, the distance L between the target base station planning point and the center point of weak coverage O(x0, y0) must satisfy L = D t -r, that is:

[0099]

[0100] Step 2: Set the search radius with the center of the area with weak signal coverage to be improved as the center of the circle, determine the circular search circle with the search radius, and obtain the total number of base stations in the search circle and the initial unordered base station list.

[0101] Set R as the search radius, and λ as the total number of base stations within the circular search circle with a radius of R. Considering that the center of the area with weak signal coverage to be improved has received the signal of the main service base station, then the main service base station A s (x s ,y s ) must be in the list of surrounding base stations, and λ must satisfy the condition λ≥1, so when setting R, the condition R≥D must be satisfied. s .

[0102] Take point O(x0,y0) as the center and R as the radius to obtain the list of surrounding λ base stations A1(x1,y1), A2(x2,y2), A i (x i ,y i ),……、A λ (x λ ,y λ ), that is, A j (x j ,y j ) represents any point on the list, assuming that the list is the initial unordered base station list, denoted by {A i (x i,y i )},i∈[1,λ].

[0103] To better illustrate the above-mentioned unordered base station list and numbering, this embodiment uses an example to illustrate: it is assumed that there are 6 unordered base station lists in a search circle with point O (x0, y0) as the center and R as the radius. At this time, these 6 base stations are randomly numbered as A1 (x1, y1), A2 (x2, y2), A3 (x3, y3), A4 (x4, y4), A5 (x5, y5), A6 (x6, y6), such as Figure 2 As shown. At this time, A4(x4,y4) is also A s (x s ,y s ).

[0104] Step 3: When the total number of base stations in the search circle is 1, the coordinates of the target base station planning point are directly obtained according to the vector extension ratio principle.

[0105] When λ=1, it means that there is only one base station in the search circle set in step 2, and this base station is the main service base station A in the center of the area to be improved with weak signal coverage O(x0,y0). s (x s ,y s ).

[0106] like Figure 3 As shown, let the coordinates of the target base station planning point be T(x t ,y t ), if the geometric angle in the search circle is optimal, then point T(x t ,y t ) must be in On the extension line of t ,y t ) and O(x0,y0) is L obtained in step 1.

[0107] According to the vector ratio principle, vector and Satisfaction between Right now:

[0108]

[0109]

[0110] Then we can obtain T(x t ,y t ), where:

[0111]

[0112] Step 4, when the total number of base stations within the search circle is greater than 1, optimize the spatial sorting of base stations, and calculate the coordinates of the target base station planning point through the maximum space geometry algorithm.

[0113] Step 4-1: Sort the initial unordered base station list obtained in Step 2 in the counterclockwise direction and re-number it to form an ordered base station list.

[0114] A i (x i ,y i ) is any point on the initial unordered base station list {A i (x i ,y i ), i ∈ [1, λ]}. Let W(x0 + 1, y0) be a point on the positive half-axis of the horizontal X-axis with O(x0, y0) as the origin. Then ∠A i OW can represent the included angle between the vector and . Since the value range of the vector included angle is [0, π], and the angle in space is a complete circumferential angle, that is, the range is [0, 2π). Therefore, if the magnitude of ∠A i OW is used to represent the counterclockwise order of point A i (x i ,y i ) centered at O(x0, y0), then the included angle value range of the vector i (x i ,y i ) formed by point A and with O(x0, y0) needs to be converted to (π, 2π).

[0115] can be represented as (1, 0), can be represented as (x i - x0, y i - y0). According to the vector included angle formula , find the magnitude of ∠A i (x i ,y i ) corresponding to ∠A i OW according to the following formula:

[0116] When y i ≥ y0,

[0117] When y i < y0,

[0118] Next, according to the value of ∠A i OW, sort the initial unordered base station list {Ai (x i , y i ), i ∈ [1, λ] are re - sorted to obtain the sorted ordered base - station list as A1(x1, y1), A2(x2, y2), A j (x j , y j ), ……, A λ (x λ , y λ ), denoted as {A j (x j , y j ), j ∈ [1, λ].

[0119] To better illustrate the above principle, we give an example. Let λ = 6. Sort the 6 unordered base - station lists in step 2 according to the above method and re - number them as A1(x1, y1), A2(x2, y2), A3(x3, y3), A4(x4, y4), A5(x5, y5), A6(x6, y6). The sorted base - station numbers and distributions are as Figure 4 shown. At this time, A3(x3, y3) is A s (x s , y s ).

[0120] Step 4 - 2: Calculate the included angles between the coordinates of any two adjacent base - stations in the ordered base - station list and the center of the weak - signal - coverage area to be improved, compare to obtain the maximum included angle, and record the coordinates of the two base - stations that form the maximum included angle.

[0121] Let A j (x j , y j ) be any point in the ordered base - station list {A j (x j , y j ), j ∈ [1, λ] obtained in step 4. Then the adjacent point of point A j (x j , y j ) is:

[0122] When j = 1, the adjacent points of A1(x1, y1) are A2(x2, y2) and A λ (x λ , y λ );

[0123] When 1 < j < λ, the adjacent points of A j (x j , y j ) are A j-1 (x j-1 , y j-1 ) and Aj+1 (x j+1 ,y j+1 );

[0124] When j = λ, A λ (x λ ,y λ ) has an adjacent point A λ-1 (x λ-1 ,y λ-1 ) and A1(x1,y1).

[0125] Therefore, the ordered base station list {A j (x j ,y j )}, j∈[1,λ], there are a total of λ angles between the coordinates of all adjacent base stations and the point O(x0,y0), and the calculation formula is as follows:

[0126] When 1≤j<λ,

[0127]

[0128] When j = λ,

[0129]

[0130] Among the λ angles obtained above, compare and obtain a maximum angle, and record the coordinates of the two base stations that constitute the maximum angle. Let the coordinates of the two base stations be A and B respectively. m (x m ,y m ), A n (x n ,y n ), then the maximum angle is ∠A m OA n .

[0131] Step 4-3: According to the principle of the triangle incenter formula, find the equation of the straight line where the angle bisector of the maximum angle in step 4-2 lies.

[0132] like Figure 4 As shown, point O (x0, y0) is the center of the area with weak signal coverage to be improved, and point A m (x m ,y m ), A n (x n ,y n ) and O(x0,y0) form the maximum angle ∠A obtained in step 4-1 m OA n , and the three points directly form a triangle ΔA m OA n .like Figure 3As shown, through O(x0,y0), A m (x m ,y m ), A n (x n ,y n ) The coordinates of the three points can be obtained as ΔA m OA n The three side lengths are:

[0133]

[0134] Let P(x p ,y p ) is a triangle A m OA n The inner heart can be obtained from the inner heart formula

[0135]

[0136] like Figure 5 As shown, according to the principle of the incenter of a triangle, ∠A m OA n The straight line on which the angle bisector of p ,y p ), then the equation of the angle bisector OP is This equation can be converted into the standard straight line equation form:

[0137] y=kx+l,where l = x p y0-x0y p

[0138] Step 4-4: Based on the straight line equation and the distance between the two points, construct a two-variable linear equation to solve the two sets of target base station planning point coordinates.

[0139] Assume the coordinates of the target base station planning point are T(x t ,y t ), if the geometric angle in the search circle is optimal, then point T(x t ,y t ) must be on the straight line equation obtained in step 4-3, and T(x t ,y t ) is L obtained in step 1, then the coordinate x t ,y t Satisfies the following formula:

[0140] (1)y t =kx t +l

[0141] (2)(x t-x0) 2 +(y t -y0) 2 =L 2

[0142] Combining the above two equations and converting them into a standard two-variable linear equation is:

[0143] ax t 2 +bx t +c=0, where

[0144] a=k 2 +l,

[0145] b = 2kl-2ky0-2x0,

[0146] c=x0 2 +(l-y0) 2 -L 2

[0147] Since this equation has two sets of solutions, let the coordinates of the target base station planning points be T(x t ,y t )、T'(x t ',y t '), the solutions are:

[0148]

[0149] It is not difficult to see that the coordinates of the two points T(x t ,y t )、T'(x t ',y t '), a point is located at ∠A m OA n The other point is on the angle bisector of ∠A m OA n On the extension line of the angle bisector.

[0150] Step 4-5: Based on the spatial geometric angle optimization algorithm, select the coordinates of the target base station planning point that has a larger angle with the weak coverage center point and the main serving base station cell.

[0151] Calculate the two groups of target base station planning points in step 4-4, the center of the weak signal coverage area to be improved O(x0,y0) and the main service base station A s (x s ,y s ), that is, calculate ∠A s OT, ∠A s OT', the formula is as follows:

[0152]

[0153] When ∠A s OT>∠A s OT', the target base station planning point coordinates are selected as T(x t ,y t ),

[0154] When ∠A s OT<∠A s OT', the target base station planning point coordinates are selected as T'(x t ',y t ').

[0155] When ∠A s OT=∠A s OT', T(x t ,y t )、T'(x t ',y t ') Just pick any point.

[0156] To illustrate the improvement of this embodiment compared with the prior art, this embodiment uses an example: it is assumed that a 5G base station needs to be planned and constructed within a search circle with a radius of 2 kilometers to improve the network signal of a certain area with weak signal coverage to be improved. There are currently 6 existing network base stations in the search circle. The comparison results between the prior art and the method of this embodiment are as follows:

[0157] (1) Improved site selection accuracy: Existing site selection methods based on experience and manual surveys usually require multiple on-site surveys and adjustments, and are highly subjective, making it difficult to ensure consistency in site selection plans. The method of this embodiment can directly recommend an optimal base station site through calculation, and can uniformly correct the site selection accuracy through the propagation model, and can ensure the consistency of the site selection plan. By comparison, it can be seen that the site selection accuracy of the method of this embodiment is significantly improved in terms of adjustability and consistency.

[0158] (2) Improved site selection efficiency: The existing simulation-based site selection method assumes that 10 candidate base stations need to be generated first, which requires at least 10 calculations. Then, the signal coverage of these 10 candidate base stations is simulated separately, which requires at least 10 calculations. The distance between the candidate base station and the six existing base stations in the search circle is then combined to obtain an optimal base station site through comparison, which requires 60 calculations. Thus, if there are currently six existing base stations in the search circle, the existing method requires at least 80 calculations to obtain the optimal base station site. However, the method of this embodiment first obtains the distance L between the target base station planning point and the weak coverage center point, which needs to be calculated once; then the angles between the six existing base stations and the horizontal positive coordinate axis are obtained to spatially sort the base station list, which needs to be calculated six times; then the coordinates of the two base stations with the largest angle between adjacent base stations are obtained, which needs to be calculated six times; then the equation of the straight line where the angle bisector of the maximum angle is located is constructed, which needs to be calculated once; then two sets of target base station planning point coordinates are solved, which needs to be calculated once; finally, the target base station planning point coordinates with a larger angle with the weak coverage center point and the main service base station cell are selected, which needs to be calculated twice. In this way, if there are currently six existing base stations in the search circle, the method of this embodiment only needs 17 calculations to obtain the optimal base station site selection. By comparison, it is found that the site selection efficiency of the method of this embodiment is 4 times higher than that of the prior art.

[0159] The present invention provides a base station site selection method based on a spatial optimization algorithm and measured signal model calibration. There are many methods and ways to implement the technical solution. The above is only a preferred implementation of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented using existing technologies.

Claims

1. A base station site selection method based on a spatial optimization algorithm and measured signal model calibration, characterized in that: The following steps are involved: Step 1: determine the center point and radius of the area with weak signal coverage to be improved, measure the field strength value and main service cell number of the center point of weak signal coverage, set the target field strength value of the area with weak signal coverage to be improved, and calculate the distance between the target base station planning point and the center point of weak coverage according to the signal propagation model; Step 2: Set the search radius with the center of the area with weak signal coverage to be improved as the center, determine the circular search circle with the search radius, and obtain the total number of base stations in the search circle and the initial unordered base station list; Step 3: When the total number of base stations in the search circle is 1, the coordinates of the target base station planning point are directly obtained according to the vector extension ratio principle; Step 4: When the total number of base stations in the search circle is greater than 1, optimize the spatial sorting of the base stations and calculate the coordinates of the target base station planning point through the maximum spatial geometry algorithm.

2. The method according to claim 1, characterized in that Step 1 includes: setting O(x0, y0) as the center point of the area with weak signal coverage to be improved, E s is the initial field strength value at point O(x0,y0), C ID is the primary serving base station cell number of point O(x0,y0); The cell number is C. ID The main service base station, assuming the coordinates of the main service base station are A s (x s ,y s ), according to the distance formula between two points, the distance between point O(x0,y0) and the main service base station A is obtained s (x s ,y s ) is D s ; Assume E t is the target field strength value at point O(x0,y0), D t The field strength is E t The distance between the time point O(x0,y0) and the corresponding primary serving base station cell.

3. The method according to claim 2, characterized in that In step 1, according to the free space loss formula: Lbs = 32.45 + 20lgF + 20lgD, where Lbs represents the total propagation loss; F represents the frequency; and D represents the propagation distance. When the propagation distance is given by D s Change to D t The propagation loss change value Δ Lbs for: Δ Lbs =20lgD s -20lgD t ; Consider E t 、E s If is a negative number, then: Δ Lbs =And s -AND t ; Find D t The values ​​are:

4. The method according to claim 3, characterized in that In step 1, let r be the radius of the area where signal weak coverage is to be improved. Then the distance L between the target base station planning point and the weak coverage center point O(x0, y0) must satisfy L = D t -r, the formula is:

5. The method according to claim 4, characterized in that Step 2 includes: setting R as the search radius, λ as the total number of base stations in the circular search circle with a radius of R; since the center of the area with weak signal coverage to be improved has received the signal of the main service base station, the main service base station A s (x s ,y s ) must be in the list of λ base stations in the search circle, λ satisfies the condition λ≥1, and when setting R, the condition R≥D must be satisfied s ; Take point O(x0,y0) as the center and R as the radius to obtain the list of surrounding λ base stations A1(x1,y1), A2(x2,y2), A i (x i ,y i ),……、A λ (x λ ,y λ ), that is, A i (x i ,y i ) is represented as any point on the list, and the list of surrounding λ base stations is the initial unordered base station list, recorded as {A i (x i ,y i )},i∈[1,λ].

6. The method according to claim 5, characterized in that Step 3 includes: when λ=1, it means that there is only one base station in the search circle set in step 2, and the base station is the main service base station A of the center O(x0, y0) of the area to be improved with weak signal coverage s (x s ,y s ); Assume the coordinates of the target base station planning point are T(x t ,y t ), if the geometric angle in the search circle is optimal, then point T(x t ,y t ) must be in On the extension line of t ,y t ) and O(x0,y0) is L obtained in step 1; According to the vector ratio principle, vector and Satisfaction between Then we can obtain T(x t ,y t ), where:

7. The method according to claim 6, characterized in that Step 4 includes: Step 4-1, sort the initial unordered base station list obtained in step 2 in a counterclockwise direction and renumber it to form an ordered base station list: In the plane rectangular coordinate system, let W(x0+1,y0) be a point on the positive half axis of the horizontal X-axis with O(x0,y0) as the origin, then ∠A i OW represents vector and If ∠A is used i The size of OW represents point A i (x i ,y i ) in counterclockwise order with O(x0,y0) as the center, then point A below the X axis needs to be i (x i ,y i ) and O(x0,y0) and The range of the angle value is converted to (π, 2π); It is represented as (1,0), It is expressed as (x i -x0,y i -y0), according to the vector angle formula Calculate each A according to the following formula i (x i ,y i ) corresponds to ∠A i OW size: When i When ≥y0, When y i < y < 0, Next, according to ∠A i The OW value is sorted in ascending order for the initial unordered base station list {A i (x i ,y i )}, i∈[1,λ] are reordered to obtain the ordered base station list as A1(x1,y1), A2(x2,y2), A j (x j ,y j ),……、A λ (x λ ,y λ ), denoted as {A j (x j ,y j )},j∈[1,λ]; Step 4-2, calculate the angle between the coordinates of any two adjacent base stations in the ordered base station list and the center of the area with weak signal coverage to be improved, compare and obtain the maximum angle, and record the coordinates of the two base stations that form the maximum angle; Step 4-3, according to the principle of the triangle incenter formula, find the equation of the straight line where the angle bisector of the maximum angle in step 4-2 is located; Step 4-4, based on the straight line equation and the distance between the two points, construct a two-variable linear equation to solve the two sets of target base station planning point coordinates; Step 4-5: Based on the spatial geometric angle optimization algorithm, select the coordinates of the target base station planning point that has a larger angle with the weak coverage center point and the main serving base station cell.

8. The method according to claim 7, characterized in that Step 4-2 Including: Assume A j (x j ,y j ) is the ordered base station list obtained in step 4 {A j (x j ,y j )}, j∈[1,λ], then point A j (x j ,y j )’s adjacent points are: When j = 1, the adjacent points of A1(x1, y1) are A2(x2, y2) and A λ (x λ ,y λ ); When 1 < j < λ, A j (x j , y j ) has adjacent points A j-1 (x j-1 , y j-1 ) and A j+1 (x j+1 , y j+1 ); When j = λ, A λ (x λ ,y λ ) has an adjacent point A λ-1 (x λ-1 ,y λ-1 ) and A1(x1,y1); Therefore, the ordered base station list {A j (x j ,y j )}, j∈[1,λ], there are a total of λ angles between the coordinates of all adjacent base stations and the point O(x0,y0), and the calculation formula is: When 1≤j<λ, When j = λ, Among the obtained λ angles, compare and get the maximum angle, and record the coordinates of the two base stations that form the maximum angle. Let the coordinates of the two base stations be A and m (x m ,y m ), A n (x n ,y n ), then the maximum angle is ∠A m OA n .

9. The method according to claim 8, characterized in that Step 4-3 includes: point O (x0, y0) is the center of the area with weak signal coverage to be improved, point A m (x m ,y m ), A n (x n ,y n ) and O(x0,y0) form the maximum angle ∠A obtained in step 4-1 m OA n , and point A m (x m ,y m ), A n (x n ,y n ) and O(x0,y0) directly form a triangle ΔA m OA n ; Through O(x0,y0), A m (x m ,y m ), A n (x n ,y n ) The coordinates of the three points give the triangle ΔA m OA n The three side lengths are: Let P(x p ,y p ) is a triangle A m OA n The inner heart is obtained by the inner heart formula: Triangle ∠A m OA n The straight line on which the angle bisector of p ,y p ), then the equation of the angle bisector OP is Convert the equation to standard straight line form: y=kx+l, The slope Intercept l = x p y0-x0y p .

10. The method according to claim 9, characterized in that Step 4-4 includes: assuming that the coordinates of the target base station planning point are T(x t ,y t ), if the geometric angle in the search circle is optimal, then point T(x t ,y t ) must be on the straight line equation obtained in step 4-3, and T(x t ,y t ) is L obtained in step 1, then the coordinate x t ,y t Satisfies the following formula: y t =kx t +l (x t −x0) 2 +( y t −y0) 2 =L 2 Convert to a standard linear equation in two variables: ax t 2 +bx t +c=0, in, Intermediate parameter a = k 2 +l, The intermediate parameter b = 2kl-2ky0-2x0, Intermediate parameter c = x0 2 +(l-y0) 2 -L 2 ; Assume that the coordinates of the target base station planning points are T(x t ,y t )、T'(x t ',y t '), the solutions are: y t =kx t +l: y t '=kx t '+l: The coordinates of the two points T(x t ,y t )、T'(x t ',y t '), a point is located at ∠A m OA n The other point is on the angle bisector of ∠A m OA n On the extension of the angle bisector of ; Step 4-5 includes: respectively calculating the two groups of target base station planning points and the center of the weak signal coverage area to be improved O(x0, y0) and the main service base station A in step 4-4 s (x s ,y s ), that is, calculate ∠A s OT, ∠A s OT', the formula is: When ∠A s OT>∠A s OT', the target base station planning point coordinates are selected as T(x t ,y t ), When ∠A s OT<∠A s OT', the target base station planning point coordinates are selected as T'(x t ',y t '); When ∠A s OT=∠A s OT', from T(x t ,y t )、T'(x t ',y t ') to select any point.

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