Indoor wireless communication system performance analysis method considering wall influence

Abstract

The invention discloses an indoor wireless communication system performance analysis method considering wall influence, which relates to the technical field of wireless communication, and comprises the following steps: analyzing the sight distance probability of a communication signal based on indoor obstacle distribution; based on the sight distance probability, establishing a channel matrix considering the wall influence; and analyzing the spectrum efficiency of the communication system according to the channel matrix. According to the method, factors such as obstacle density and height are comprehensively considered, the indoor signal propagation sight distance probability is analyzed, the spectrum efficiency performance of an indoor scene is analyzed based on the electromagnetic characteristics and deployment positions of wall materials, and the optimal wall deployment angle interval and the optimal relative dielectric constant range are provided. At present, all existing indoor communication system performance analysis methods neglect the influence of the wall body, and the method explains and explains a mechanism that the wall body acts on the communication performance and analyzes key influence parameters, and has guiding significance for performance optimization of the indoor communication system.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a method for analyzing the performance of an indoor wireless communication system taking into account the influence of walls. Background Art

[0002] With the acceleration of urbanization and the promotion of the Industrial Internet of Things, indoor communications are attracting significant attention. By 2022, indoor communications traffic will account for over 80% of the total traffic of fifth-generation (5G) mobile communication systems. Indoor hotspots, factory production lines, and industrial manufacturing areas will remain key applications for future sixth-generation (6G) mobile communication systems. In indoor communication scenarios, wall obstruction is unavoidable and significantly impacts communication system performance. Therefore, research is urgently needed to design indoor communication system deployment plans based on wall layout and materials, achieving a balanced optimization of communication performance and energy consumption.

[0003] Existing performance analysis methods for indoor communication systems only consider information such as base station location and user distribution, with limited consideration of scenario parameters such as building layout and wall material. Existing research has demonstrated that optimizing building layout can improve system performance without incurring additional costs. However, current building layout optimization approaches are mostly based on simplified scenarios, ignoring the correlation between wall layout, user distribution, and obstacle distribution. Furthermore, existing research focuses solely on wall location, ignoring the influence of the electromagnetic properties of the wall material itself. Furthermore, current performance analysis of indoor communication systems is mostly based on simplified channel models and employs macroscopic analysis, lacking detailed analysis of the specific impact of walls.

[0004] Because walls are an important component of indoor buildings, their material and location have a significant impact on the performance of wireless communication systems. Existing research lacks a systematic performance evaluation method for indoor wireless communication systems that considers the influence of walls. This results in a lack of clear optimization targets and optimization effect evaluation methods for current optimization research. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a performance analysis method for indoor wireless communication systems taking into account the influence of walls, study the line-of-sight signal probability in indoor scenes and the spectrum efficiency performance under different wall materials and positions, and provide guidance for the optimization of indoor communication scenes and a reasonable performance evaluation method.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] A method for analyzing indoor wireless communication system performance considering the influence of walls proposed in the present invention includes:

[0008] Step S1: Analyze the line-of-sight probability of the communication signal based on the indoor obstacle distribution;

[0009] Step S2: Based on the line-of-sight probability, a channel matrix is established that takes into account the influence of walls.

[0010] Step S3: Analyze the spectrum efficiency of the communication system according to the channel matrix.

[0011] As a further optimization scheme of the indoor wireless communication system performance analysis method considering the influence of walls described in the present invention, the line-of-sight probability P(D)=exp{ln[P(D)]},

[0012]

[0013] Where D is the horizontal projection distance between the user and the base station, erf(·) is the error function, is the signal propagation pitch angle, σ is the Rayleigh scale distribution parameter, λ is the indoor obstacle density, z T is the coordinate of the base station on the Z axis.

[0014] As a further optimization solution of the indoor wireless communication system performance analysis method considering the influence of walls according to the present invention, the line-of-sight probability includes:

[0015] Set the origin of the coordinate system to the ground corner vertex of the outermost wall of the building, define the ground as the XY plane, and establish a three-dimensional Cartesian coordinate system; the user position coordinate is (x R ,y R ,z R ), x R 、y R 、z R are the coordinates of the user on the X-axis, Y-axis and Z-axis respectively; the base station position coordinates are (x T ,y T ,z T ), x T 、y T 、z T are the coordinates of the base station on the X-axis, Y-axis, and Z-axis; R antennas, the base station is equipped with N T antennas; assuming the obstacle height follows Rayleigh distribution;

[0016] Calculate the horizontal projection distance between the user and the base station When , the exponential function of the sight distance probability is

[0017]

[0018] in,

[0019] The line-of-sight probability P(D)=exp{ln[P(D)]}.

[0020] As a further optimization solution of the indoor wireless communication system performance analysis method considering the influence of walls according to the present invention, step S2 includes:

[0021] Step S201: Based on the line-of-sight probability obtained in step S1, the path loss of signal propagation is obtained, as follows:

[0022] According to the line-of-sight probability, the path loss PL(D) of indoor signal propagation is obtained as

[0023] PL(D)=P(D)PL LOS (D)+(1-P(D))PL NLOS (D)

[0024]

[0025]

[0026] Among them, f c is the carrier frequency, c is the speed of light, n L and n N They are the path loss indices of line-of-sight and non-line-of-sight signals, PL bl is the penetration coefficient of the wall material, PL LOS (D) is the path loss of the line-of-sight LOS signal, PL NLOS (D) is the path loss of the non-line-of-sight NLOS signal;

[0027] Step S202: Determine the role of the wall in signal propagation based on the relative positions of the wall, the user, and the base station, and analyze the corresponding small-scale fading, as follows:

[0028] According to the effect of the wall, signal propagation is divided into four situations: 1) no transmission and no reflection; 2) transmission but no reflection; 3) reflection but no transmission; 4) both transmission and reflection;

[0029] When there is neither transmission nor reflection in the signal propagation, the channel impulse response is obtained for

[0030]

[0031] Among them, q is the qth transmitting antenna, p is the pth receiving antenna, τ is the time delay, ε1 and ε3 are the power ratios of signals with different paths, is the channel impulse response of the LOS signal, is the channel impulse response of the NLOS signal;

[0032] The delay is calculated using the following formula:

[0033]

[0034] in, are the mth scattering cluster in the nth scattering cluster n The X-axis, Y-axis, and Z-axis coordinates of the scattering point of each ray;

[0035] When there is transmission but no reflection during signal propagation, the signal propagation distance AC in the XY plane of the wall is

[0036]

[0037] Among them, sgn(·) is the sign function, d w is the wall thickness, ξ2, D, E, G, ξ1, and Z are all intermediate variables. ξ3, ξ4, ξ5 are all intermediate variables, F is an intermediate variable, A=D 2 -3F,B=DF-9E 2 , A and B are intermediate variables, C=F 2 -3DE 2 , C is the intermediate variable, Δ=B 2 -4AC, Δ is the intermediate variable, Z=D 2 -DG+G 2 -3A, Z1 and Z2 are both intermediate variables;

[0038] Get the complete propagation distance in the XY plane θ1 is the incident angle of the XY plane signal entering the wall, and θ2 is the offset angle between the emission angle of the XY plane signal after penetrating the wall and the incident angle of the wall;

[0039] The calculated complete propagation distance in the YZ plane is AC' is the refraction propagation distance of the signal in the YZ plane of the wall, θ'1 is the incident angle of the YZ plane signal on the wall, θ'2 is the offset angle between the emission angle of the YZ plane signal after penetrating the wall and the incident angle of the wall, and θ'3 is the angle between the connecting line of the transceiver and the wall in the YZ plane;

[0040] There is a transmission effect, and the transmission coefficient T of the wall is obtained as

[0041]

[0042] Among them, T TE is the transmission coefficient of TE wave, TTM is the transmission coefficient of TM wave;

[0043] Then we get the channel impulse response for

[0044]

[0045] in, is the channel impulse response of the transmitted signal, is the time delay of the transmitted signal;

[0046] When there is reflection but no transmission in signal propagation, it is assumed that the boundary line expression of the wall is k2x+k3y+k4z+k5=0, where x, y, and z are variables representing the position coordinates of any point on the wall, and k2, k3, k4, and k5 are random coefficients obtained according to the actual wall position. The coordinates of the reflection point are x wr =x T +(x R -x T )m rf ,y wr =y T +(y R -y T )m rf and z wr =z T +(z R -z T )m rf , x wr 、y wr 、z wr are the calculated X-axis, Y-axis, and Z-axis coordinates of the reflection point, where the intermediate variables The calculation formula for the reflection coefficient Γ of the wall material is:

[0047]

[0048] Among them, Γ TE is the reflection coefficient of TE wave, Γ TM is the reflection coefficient of TM wave, θ is the incident angle of signal reflection;

[0049] Get the channel impulse response for

[0050] Among them, ε2 is the power ratio of signals with different paths, is the channel impulse response of the wall reflected signal, is the time delay of the signal reflected from the wall;

[0051] When there is transmission and reflection in signal propagation, the channel impulse response The expression is

[0052]

[0053] S203, obtaining a channel matrix H based on the obtained path loss and small-scale fading;

[0054] H=PL 1 / 2 ·H s

[0055] Among them, H s is the small-scale fading channel matrix, PL is the path loss, which is calculated by combining the derived PL(D) function with the propagation distance.

[0056] As a further optimization scheme of the indoor wireless communication system performance analysis method considering the influence of walls according to the present invention, ε1 and ε3 include:

[0057]

[0058] As a further optimization scheme of the indoor wireless communication system performance analysis method considering the influence of walls described in the present invention, and The details are as follows:

[0059]

[0060] Where δ(·) is the impulse function, is the delay of the LOS signal between the qth transmitting antenna and the pth receiving antenna, N qp is the number of scattering clusters between the qth transmitting antenna and the pth receiving antenna, M n is the number of rays in the nth scattering cluster, is the mth scattering cluster in the nth scattering cluster between the qth transmitting antenna and the pth receiving antenna n The ray at f c Power at frequency, is the mth scattering cluster in the nth scattering cluster between the qth transmitting antenna and the pth receiving antenna n The time delay of the ray signal.

[0061] As a further optimization scheme of the indoor wireless communication system performance analysis method considering the influence of walls described in the present invention,

[0062] ξ1=1,ξ2=-a 2 -2lcosθ3;

[0063] Among them, a is the ratio of the refractive index of air to the refractive index of the wall material, l is the straight-line distance between the transmitting and receiving ends, and its calculation expression is θ3 is the angle between the connecting line of the transmitting and receiving ends and the wall in the XY plane.

[0064] As a further optimization scheme of the indoor wireless communication system performance analysis method considering the influence of walls described in the present invention,

[0065]

[0066]

[0067] Where ε is the relative dielectric constant of the material.

[0068] As a further optimization solution of the indoor wireless communication system performance analysis method considering the influence of walls according to the present invention, step S3 includes:

[0069] Calculate the mean signal-to-interference-plus-noise ratio (SINR). The noise comes from inter-base station interference in a multi-base station system. The specific operation is as follows:

[0070] The calculation expression of signal-to-interference-plus-noise ratio E[SINR] is:

[0071]

[0072] Among them, H i is the channel matrix of the i-th base station, PL i is the path loss of the i-th base station, is the signal transmission power of the i-th base station, is the small-scale fading channel matrix of the i-th base station, H j is the channel matrix of the jth base station, PL j is the path loss of the j-th base station, is the signal transmission power of the j-th base station, is the small-scale fading channel matrix of the j-th base station, is the noise signal power, M is the total number of base stations;

[0073] The final spectrum efficiency is

[0074] As a further optimization scheme for the indoor wireless communication system performance analysis method considering the influence of walls described in the present invention, the role of the wall is that when the base station is fixed on the wall, the wall provides a reflection path for signal propagation. When the wall appears in the line-of-sight link between the user and the base station, the wall will block signal propagation, and the signal must be transmitted through the wall.

[0075] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0076] This paper considers the influence of parameters such as obstacle height, obstacle density, wall location, and wall material to calculate spectrum efficiency. By analyzing the impact of different parameters on communication system performance, it can provide guidance for optimizing communication performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 It is a flow chart of the method of the present invention;

[0078] Figure 2 is the spectrum efficiency under different propagation conditions;

[0079] Figure 3 is the spectrum efficiency at different wall placement angles;

[0080] Figure 4 is the spectrum efficiency under different wall materials. DETAILED DESCRIPTION

[0081] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0082] like Figure 1 As shown, a method for analyzing the performance of an indoor wireless communication system considering the influence of walls includes:

[0083] Step S1: Analyze the line-of-sight probability of the communication signal based on the indoor obstacle distribution;

[0084] Step S2: Based on the line-of-sight probability, a channel matrix is established that takes into account the influence of walls.

[0085] Step S3: Analyze the spectrum efficiency of the communication system according to the channel matrix.

[0086] The probability of sight distance P(D) = exp{ln[P(D)]},

[0087]

[0088] Where D is the horizontal projection distance between the user and the base station, erf(·) is the error function, is the signal propagation pitch angle, σ is the Rayleigh scale distribution parameter, λ is the indoor obstacle density, z T is the coordinate of the base station on the Z axis.

[0089] The process of obtaining the line-of-sight probability is as follows:

[0090] Set the origin of the coordinate system to the ground corner vertex of the outermost wall of the building, define the ground as the XY plane, and establish a three-dimensional Cartesian coordinate system; the user position coordinate is (x R ,y R ,z R ), xR 、y R 、z R are the coordinates of the user on the X-axis, Y-axis and Z-axis respectively; the base station position coordinates are (x T ,y T ,z T ), x T 、y T 、z T are the coordinates of the base station on the X-axis, Y-axis, and Z-axis; R antennas, the base station is equipped with N T antennas; assuming the obstacle height follows Rayleigh distribution;

[0091] Calculate the horizontal projection distance between the user and the base station When , the exponential function of the sight distance probability is

[0092]

[0093] in,

[0094] The line-of-sight probability P(D)=exp{ln[P(D)]}.

[0095] Step S2 includes:

[0096] Step S201: Based on the line-of-sight probability obtained in step S1, the path loss of signal propagation is obtained, as follows:

[0097] According to the line-of-sight probability, the path loss PL(D) of indoor signal propagation is obtained as

[0098] PL(D)=P(D)PL LOS (D)+(1-P(D))PL NLOS (D)

[0099]

[0100] Among them, f c is the carrier frequency, c is the speed of light, n L and n N The path loss indexes of line-of-sight and non-line-of-sight signals are PL, bl is the penetration coefficient of the wall material, PL LOS (D) is the path loss of the line-of-sight LOS signal, PL NLOS (D) is the path loss of the non-line-of-sight NLOS signal;

[0101] Step S202: Determine the role of the wall in signal propagation based on the relative positions of the wall, the user, and the base station, and analyze the corresponding small-scale fading, as follows:

[0102] According to the effect of the wall, signal propagation is divided into four situations: 1) no transmission and no reflection; 2) transmission but no reflection; 3) reflection but no transmission; 4) both transmission and reflection;

[0103] When there is neither transmission nor reflection in the signal propagation, the channel impulse response is obtained for

[0104]

[0105] Among them, q is the qth transmitting antenna, p is the pth receiving antenna, τ is the time delay, ε1 and ε3 are the power ratios of signals with different paths, is the channel impulse response of the LOS signal, is the channel impulse response of the NLOS signal,

[0106]

[0107] The delay is calculated using the following formula:

[0108]

[0109] in, are the mth scattering cluster in the nth scattering cluster n The X-axis, Y-axis, and Z-axis coordinates of the scattering point of each ray;

[0110] When there is transmission but no reflection during signal propagation, the signal propagation distance AC in the XY plane of the wall is

[0111]

[0112] Among them, sgn(·) is the sign function, d w is the wall thickness, ξ2, D, E, G, ξ1, and Z are all intermediate variables. ξ1=1,ξ2=-a 2 -2lcosθ3; a is the ratio of the refractive index of air to the refractive index of the wall material, l is the straight-line distance between the transmitting and receiving ends, and its calculation expression is θ3 is the angle between the connecting line of the transmitting and receiving ends and the wall in the XY plane; ξ3, ξ4, ξ5 are all intermediate variables, F is an intermediate variable, A=D 2 -3F,B=DF-9E 2 , A and B are intermediate variables, C=F 2 -3DE 2 , C is the intermediate variable, Δ=B 2 -4AC, Δ is the intermediate variable, Z=D 2 -DG+G 2 -3A, Z1 and Z2 are both intermediate variables;

[0113] Get the complete propagation distance in the XY plane θ1 is the incident angle of the XY plane signal entering the wall, and θ2 is the offset angle between the emission angle of the XY plane signal after penetrating the wall and the incident angle of the wall;

[0114] The calculated complete propagation distance in the YZ plane is AC' is the refraction propagation distance of the signal in the YZ plane of the wall, θ'1 is the incident angle of the YZ plane signal on the wall, θ'2 is the offset angle between the emission angle of the YZ plane signal after penetrating the wall and the incident angle of the wall, and θ'3 is the angle between the connecting line of the transceiver and the wall in the YZ plane;

[0115] There is a transmission effect, and the transmission coefficient T of the wall is obtained as

[0116]

[0117] Among them, T TE is the transmission coefficient of TE wave, T TM is the transmission coefficient of TM wave, and ε is the relative dielectric constant of the material.

[0118] Then we get the channel impulse response for

[0119]

[0120] in, is the channel impulse response of the transmitted signal, is the time delay of the transmitted signal;

[0121] When there is reflection but no transmission in signal propagation, it is assumed that the boundary line expression of the wall is k2x+k3y+k4z+k5=0, where x, y, and z are variables representing the position coordinates of any point on the wall, and k2, k3, k4, and k5 are random coefficients obtained according to the actual wall position. The coordinates of the reflection point are x wr =x T +(x R -x T )m rf ,y wr =y T +(y R -y T )m rf and z wr =z T +(zR -z T )m rf , x wr 、y wr 、z wr are the calculated X-axis, Y-axis, and Z-axis coordinates of the reflection point, where the intermediate variables The calculation formula for the reflection coefficient Γ of the wall material is:

[0122]

[0123] Among them, Γ TE is the reflection coefficient of TE wave, Γ TM is the reflection coefficient of TM wave, θ is the incident angle of signal reflection;

[0124] Get the channel impulse response for

[0125] Among them, ε2 is the power ratio of signals with different paths, is the channel impulse response of the wall reflected signal, is the time delay of the signal reflected from the wall;

[0126] When there is transmission and reflection in signal propagation, the channel impulse response The expression is

[0127]

[0128] S203, obtaining a channel matrix H based on the obtained path loss and small-scale fading;

[0129] H=PL 1 / 2 ·H s

[0130] Among them, H s is the small-scale fading channel matrix, PL is the path loss, which is calculated by combining the derived PL(D) function with the propagation distance.

[0131] and The details are as follows:

[0132]

[0133] Where δ(·) is the impulse function, is the delay of the LOS signal between the qth transmitting antenna and the pth receiving antenna, N qp is the number of scattering clusters between the qth transmitting antenna and the pth receiving antenna, M n is the number of rays in the nth scattering cluster, is the mth scattering cluster in the nth scattering cluster between the qth transmitting antenna and the pth receiving antenna n The ray at f c Power at frequency, is the mth scattering cluster in the nth scattering cluster between the qth transmitting antenna and the pth receiving antenna n The time delay of the ray signal.

[0134] Step S3 includes:

[0135] Calculate the mean signal-to-interference-plus-noise ratio (SINR). The noise comes from inter-base station interference in a multi-base station system. The specific operation is as follows:

[0136] The calculation expression of signal-to-interference-plus-noise ratio E[SINR] is:

[0137]

[0138] Among them, H i is the channel matrix of the i-th base station, PL i is the path loss of the i-th base station, is the signal transmission power of the i-th base station, is the small-scale fading channel matrix of the i-th base station, H j is the channel matrix of the jth base station, PL j is the path loss of the j-th base station, is the signal transmission power of the j-th base station, is the small-scale fading channel matrix of the j-th base station, is the noise signal power, M is the total number of base stations;

[0139] The final spectrum efficiency is

[0140] The function of a wall is that when a base station is fixed on a wall, the wall provides a reflection path for signal propagation. When a wall appears in the line-of-sight link between the user and the base station, the wall will block signal propagation, and the signal must be transmitted through the wall.

[0141] Example 1:

[0142] S1. Consider an indoor scenario measuring 50m × 50m × 7m, with a communication frequency of 2.4GHz, an obstacle density of 1 obstacle / meter, and an average height of 2m. Four base stations are deployed on the ceiling, evenly spaced and equipped with 32 antennas. Users are randomly distributed indoors, each at a height of 1.5m and equipped with four antennas. The path loss exponent for line-of-sight signals is 1.6, and the path loss exponent for non-line-of-sight signals is 4. Using these parameters, calculate the indoor line-of-sight probability.

[0143] S2. Considering that the wall thickness is 0.3m, the walls are evenly spaced according to the preset number, and the corresponding channel impulse response is obtained according to the user, base station and wall positions;

[0144] S3. Calculate the spectrum efficiency.

[0145] Analyze the spectrum efficiency under different propagation conditions and draw the graph. The specific results are as follows: Figure 2 shown. Figure 2 The spectral efficiency is shown for three scenarios: no transmission and reflection, transmission without reflection, and reflection without transmission. The results show that when the wall provides a strong reflection signal, the received signal is enhanced, resulting in the best spectral efficiency. When the wall only provides transmission, the spectral efficiency decreases due to the wall's blocking effect.

[0146] When the signal-to-noise ratio at the transmitter is set to 0dB, 5dB, and 10dB, the effect of the angle between the wall and the line-of-sight link on the spectrum efficiency is analyzed and plotted. The specific results are as follows: Figure 3 shown. Figure 3 The figure shows how spectral efficiency changes when the angle varies between (0 and π / 2). Spectral efficiency is highest when the line-of-sight link is perpendicular to the wall. When the angle exists, system performance first decreases, then increases, and then decreases again, achieving optimal performance near π / 4.

[0147] When the refractive index of the wall material is set to 1.4, 1.5, and 1.6 respectively, the influence of the relative dielectric constant of the wall material on the spectrum efficiency is analyzed and plotted. The specific results are as follows Figure 4 shown. Figure 4 The figure shows how spectral efficiency changes as the relative permittivity varies in the range (0,100). Spectral efficiency reaches its optimum when the relative permittivity is around 70. The refractive index of the wall material also affects communication system performance; improving it can also improve performance.

[0148] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for analyzing the performance of an indoor wireless communication system considering the influence of walls, characterized in that: include: Step S1: Analyze the line-of-sight probability of the communication signal based on the indoor obstacle distribution; Step S2: Based on the line-of-sight probability, a channel matrix is established that takes into account the influence of walls. Step S3: Analyze the spectrum efficiency of the communication system according to the channel matrix.

2. The method for analyzing indoor wireless communication system performance considering the influence of walls according to claim 1, characterized in that: The probability of sight distance P(D) = exp{ln[P(D)]}, Where D is the horizontal projection distance between the user and the base station, erf(·) is the error function, is the signal propagation pitch angle, σ is the Rayleigh scale distribution parameter, λ is the indoor obstacle density, z T is the coordinate of the base station on the Z axis.

3. The method for analyzing indoor wireless communication system performance considering the influence of walls according to claim 2, characterized in that: The line-of-sight probabilities include: Set the origin of the coordinate system to the ground corner vertex of the outermost wall of the building, define the ground as the XY plane, and establish a three-dimensional Cartesian coordinate system; the user position coordinate is (x R ,y R ,z R ), x R 、y R 、z R are the coordinates of the user on the X-axis, Y-axis and Z-axis respectively; the base station position coordinates are (x T ,y T ,z T ), x T 、y T 、z T are the coordinates of the base station on the X-axis, Y-axis, and Z-axis; R antennas, the base station is equipped with N T antennas; assuming the obstacle height follows Rayleigh distribution; Calculate the horizontal projection distance between the user and the base station When , the exponential function of the sight distance probability is in, The line-of-sight probability P(D)=exp{ln[P(D)]}.

4. The method for analyzing indoor wireless communication system performance considering the influence of walls according to claim 3, characterized in that: Step S2 includes: Step S201: Based on the line-of-sight probability obtained in step S1, the path loss of signal propagation is obtained, as follows: According to the line-of-sight probability, the path loss PL(D) of indoor signal propagation is obtained as PL(D)=P(D)PL LOS (D)+(1-P(D))PL NLOS (D) Among them, f c is the carrier frequency, c is the speed of light, n L and n N The path loss indexes of line-of-sight and non-line-of-sight signals are PL, bl is the penetration coefficient of the wall material, PL LOS (D) is the path loss of the line-of-sight LOS signal, PL NLOS (D) is the path loss of the non-line-of-sight NLOS signal; Step S202: Determine the role of the wall in signal propagation based on the relative positions of the wall, the user, and the base station, and analyze the corresponding small-scale fading, as follows: According to the effect of the wall, signal propagation is divided into four situations: 1) no transmission and no reflection; 2) transmission but no reflection; 3) reflection but no transmission; 4) both transmission and reflection; When there is neither transmission nor reflection in the signal propagation, the channel impulse response is obtained for Among them, q is the qth transmitting antenna, p is the pth receiving antenna, τ is the time delay, ε1 and ε3 are the power ratios of signals with different paths, is the channel impulse response of the LOS signal, is the channel impulse response of the NLOS signal; The delay is calculated using the following formula: in, are the mth scattering cluster in the nth scattering cluster n The X-axis, Y-axis, and Z-axis coordinates of the scattering point of each ray; When there is transmission but no reflection during signal propagation, the signal propagation distance AC in the XY plane of the wall is Among them, sgn(·) is the sign function, d w is the wall thickness, ξ2, D, E, G, ξ1, and Z are all intermediate variables. ξ3, ξ4, ξ5 are all intermediate variables, F is an intermediate variable, A=D 2 -3F,B=DF-9E 2 , A and B are intermediate variables, C=F 2 -3DE 2 , C is the intermediate variable, Δ=B 2 -4AC, Δ is the intermediate variable, Z=D 2 -DG+G 2 -3A, Z1 and Z2 are intermediate variables; Get the complete propagation distance in the XY plane θ1 is the incident angle of the XY plane signal entering the wall, and θ2 is the offset angle between the emission angle of the XY plane signal after penetrating the wall and the incident angle of the wall; The calculated complete propagation distance in the YZ plane is AC' is the refraction propagation distance of the signal in the YZ plane of the wall, θ'1 is the incident angle of the YZ plane signal on the wall, θ'2 is the offset angle between the emission angle of the YZ plane signal after penetrating the wall and the incident angle of the wall, and θ'3 is the angle between the connecting line of the transceiver and the wall in the YZ plane; There is a transmission effect, and the transmission coefficient T of the wall is obtained as Among them, T TE is the transmission coefficient of TE wave, T TM is the transmission coefficient of TM wave; Then we get the channel impulse response for in, is the channel impulse response of the transmitted signal, is the time delay of the transmitted signal; When there is reflection but no transmission in signal propagation, assume that the boundary line expression of the wall is k2x+k3y+k4z+k5=0, where x, y, and z are variables representing the position coordinates of any point on the wall, and k2, k3, k4, and k5 are random coefficients obtained based on the actual wall position. The coordinates of the reflection point are x wr =x T +(x R -x T )m rf ,y wr =y T +(y R -y T )m rf and z wr =z T +(z R -z T )m rf , x wr 、y wr 、z wr are the calculated X-axis, Y-axis, and Z-axis coordinates of the reflection point, where the intermediate variables The calculation formula for the reflection coefficient Γ of the wall material is: Among them, Γ TE is the reflection coefficient of TE wave, Γ TM is the reflection coefficient of TM wave, θ is the incident angle of signal reflection; Get the channel impulse response for Among them, ε2 is the power ratio of signals with different paths, is the channel impulse response of the wall reflected signal, is the delay of the signal reflected from the wall; When there is transmission and reflection in signal propagation, the channel impulse response The expression is S203, obtaining a channel matrix H based on the obtained path loss and small-scale fading; H=PL 1 / 2 ·H s Among them, H s is the small-scale fading channel matrix, PL is the path loss, which is calculated by combining the derived PL(D) function with the propagation distance.

5. The method for analyzing indoor wireless communication system performance considering the influence of walls according to claim 4, characterized in that: ε1 and ε3 include:

6. The method for analyzing indoor wireless communication system performance considering the influence of walls according to claim 4, characterized in that: and The details are as follows: Where δ(·) is the impulse function, is the delay of the LOS signal between the qth transmitting antenna and the pth receiving antenna, N qp is the number of scattering clusters between the qth transmitting antenna and the pth receiving antenna, M n is the number of rays in the nth scattering cluster, is the mth scattering cluster in the nth scattering cluster between the qth transmitting antenna and the pth receiving antenna n The ray at f c Power at frequency, is the mth scattering cluster in the nth scattering cluster between the qth transmitting antenna and the pth receiving antenna n The time delay of the ray signal.

7. The method for analyzing indoor wireless communication system performance considering the influence of walls according to claim 4, characterized in that: ξ1=1,ξ2=-a 2 -2l cosθ3; Among them, a is the ratio of the refractive index of air to the refractive index of the wall material, l is the straight-line distance between the transmitting and receiving ends, and its calculation expression is θ3 is the angle between the connecting line of the transmitting and receiving ends and the wall in the XY plane.

8. The method for analyzing indoor wireless communication system performance considering the influence of walls according to claim 4, characterized in that: Where ε is the relative dielectric constant of the material.

9. The method for analyzing indoor wireless communication system performance considering the influence of walls according to claim 1, characterized in that: Step S3 includes: Calculate the mean signal-to-interference-plus-noise ratio (SINR). The noise comes from inter-base station interference in a multi-base station system. The specific operation is as follows: The calculation expression of signal-to-interference-plus-noise ratio E[SINR] is: Among them, H i is the channel matrix of the i-th base station, PL i is the path loss of the i-th base station, is the signal transmission power of the i-th base station, is the small-scale fading channel matrix of the i-th base station, H j is the channel matrix of the jth base station, PL j is the path loss of the j-th base station, is the signal transmission power of the j-th base station, is the small-scale fading channel matrix of the j-th base station, is the noise signal power, M is the total number of base stations; The final spectrum efficiency is 10. The method for analyzing indoor wireless communication system performance considering the influence of walls according to claim 4, characterized in that: The function of a wall is that when a base station is fixed on a wall, the wall provides a reflection path for signal propagation. When a wall appears in the line-of-sight link between the user and the base station, the wall will block signal propagation, and the signal must be transmitted through the wall.

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