CN112770328A - Statistical method field division-based wireless equipment coverage optimization method for tunnel environment - Google Patents
Statistical method field division-based wireless equipment coverage optimization method for tunnel environment Download PDFInfo
- Publication number
- CN112770328A CN112770328A CN202011353454.9A CN202011353454A CN112770328A CN 112770328 A CN112770328 A CN 112770328A CN 202011353454 A CN202011353454 A CN 202011353454A CN 112770328 A CN112770328 A CN 112770328A
- Authority
- CN
- China
- Prior art keywords
- wireless
- polarization
- field
- tunnel
- equipment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
- H04W16/18—Network planning tools
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
- H04W16/22—Traffic simulation tools or models
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W24/00—Supervisory, monitoring or testing arrangements
- H04W24/02—Arrangements for optimising operational condition
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
- H04W4/02—Services making use of location information
- H04W4/021—Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
Abstract
The invention relates to a wireless equipment coverage optimization method for a tunnel environment based on statistical method field division. Belongs to the field of wireless communication. Firstly, wireless basic equipment acquires a position parameter of terminal equipment in a tunnel; establishing an electromagnetic field 'polarization power difference-distance' database by using the parameters; calculating the average polarization power difference in a unit observation interval by using a database; estimating an optimal antenna polarization for the wireless infrastructure device; dividing a near field region and a far field region of electromagnetic wave propagation of the wireless basic equipment; if the electromagnetic wave propagation field region does not need to be divided, the terminal and the wireless basic equipment both adopt a horizontal polarization antenna for communication; otherwise, judging whether the terminal is in a near field or a far field of the wireless basic equipment for electromagnetic wave propagation; if the field is near field, the terminal and the wireless basic equipment adopt a vertical polarization antenna to communicate, otherwise, the terminal and the wireless basic equipment adopt a horizontal polarization antenna to communicate. The method has simple steps and good optimization effect.
Description
Technical Field
The invention relates to a wireless equipment coverage optimization method, in particular to a wireless equipment coverage optimization method for a tunnel environment based on statistical method field division, which is suitable for being used underground in a tunnel, and belongs to the technical field of electromagnetic signal coverage and energy efficiency management in wireless communication.
Background
With the development of technologies such as smart cities and smart mines, wireless devices using electromagnetic signal communication are widely applied to environments such as railway and highway tunnels, subways and mines, and provide services for personnel positioning, environment monitoring, automatic production, intelligent management and the like. Wireless devices are primarily battery powered and therefore have limited power. Optimizing the wireless coverage of a device by improving the transmission energy efficiency of electromagnetic signals has many benefits, such as reducing the energy consumption of the communication device, extending the usage time of the device; the deployment density of wireless access nodes, relay nodes and the like is reduced, and the deployment cost of wireless communication equipment is reduced; the service life of the wireless network is prolonged, and the connectivity of the wireless network is enhanced.
At present, wireless coverage optimization schemes in the environments of tunnels, subways, mines and the like are provided, wherein the deployment position of wireless equipment is improved, and the beam width of a transmitting-receiving antenna is reduced. The above-described coverage scheme uses only one antenna polarization for communication throughout the coverage field. However, according to the mechanism of influence of antenna polarization on electromagnetic wave signal propagation in a tunnel (y.huo, l.zhao, q.s.hu, e.j.ding, x.h.zhao, and z.sun. "optical polarization of antenna for field coverage in the same networks", IEEE Access, vol.8, No.1, pp.2169-3536,2020.), the same polarization may produce different coverage properties in the near field and the far field of the antenna. When electromagnetic signals are transmitted in a near field region of the transmitting antenna, the vertically polarized antenna can obtain higher path loss than the horizontally polarized antenna; when the electromagnetic signal is transmitted in the far field of the transmitting antenna, only the horizontally polarized antenna can realize lower path loss. In order to further improve the transmission energy efficiency of wireless signals, it is necessary to estimate the optimal polarization of wireless communication, reasonably divide the near-field region and the far-field region of wireless communication equipment, and configure the corresponding optimal antenna polarization according to the actual propagation region of electromagnetic wave signals.
The method for dividing the near field area and the far field area of the existing wireless equipment comprises a first Fresnel gap dividing method and a system identification method. The two methods are only suitable for estimating the electromagnetic wave propagation rule of single polarization; cannot be used to compare the path losses of differently polarized electromagnetic signals and thus cannot estimate the optimal antenna polarization with higher transmission energy efficiency. Coverage optimization based on existing field division can lead to unreasonable antenna polarization configuration, resulting in higher signal transmission loss.
The existing wireless sensor network technology can provide massive useful information, such as positioning information, inertial navigation information, speed information and the like of a user, and by reasonably utilizing the information and combining an influence mechanism of antenna polarization on signal propagation, the coverage power of wireless equipment can be greatly optimized on the basis of not increasing algorithm complexity, and the transmission energy efficiency of signals is improved.
Disclosure of Invention
The technical problem is as follows: aiming at the defects of the technology, the wireless equipment coverage optimization method for the tunnel environment based on the field division of the statistical method is provided, which has the advantages of small application difficulty, simple method and capability of effectively improving the wireless signal transmission energy efficiency.
The technical scheme is as follows: in order to achieve the technical purpose, the method for optimizing the coverage of the wireless equipment for the tunnel environment based on the field division of the statistical method is suitable for a wireless basic equipment for networking and covering a wireless network in a tunnel, and comprises the following steps: such as a base station, a micro base station, a wireless access node, a relay node, and a server for storing data, a mobile terminal device is arranged in a wireless network area;
the method comprises the following steps:
a, firstly, setting a Cartesian coordinate system in the tunnel, wherein the origin of the coordinate system is positioned at the center of the tunnelThe coordinates of the antenna of the wireless infrastructure along the width, height and length of the tunnel are known as (x) using the x, y and z axes, respectively0,y0,z0)；
b, acquiring information of all mobile terminal devices in the tunnel through the server: comprising location information (x) of a mobile terminal device1, y1,z1) Information on the moving direction and the moving speed;
c, the wireless basic equipment divides the near field area and the far field area by using a statistical method, and the vertical coordinate of the position of the dividing point of the divided near field area and far field area is expressed as zDV；
If the propagation field area of the wireless basic equipment is not divided into a near field area and a far field area, the wireless basic equipment and the mobile terminal equipment both select a horizontal polarization antenna to send and receive signals;
if the ordinate z of the mobile terminal device1∈[z0-zDV,z0+zDV]If so, judging that the mobile terminal equipment is positioned in a near field area of the wireless basic equipment, and switching the wireless basic equipment to a vertical polarization antenna; if the ordinate z of the wireless infrastructure is1∈[-∞,z0-zDV]∪[z0+zDV,+∞]If the mobile terminal equipment is located in the far field area of the wireless basic equipment, the wireless basic equipment is switched to the horizontal polarization antenna for communication; and then sending a parameter configuration command to the mobile terminal equipment, and commanding the mobile terminal equipment to also adopt the same antenna polarization for communication:
d, configuring antenna polarization parameters of the wireless basic equipment and the mobile terminal equipment:
e if the wireless communication between the wireless infrastructure equipment and the mobile terminal equipment is not ended and the terminal moving speed and direction are not changed, the wireless infrastructure equipment utilizes
Determining a refreshing period of the antenna polarization parameter, wherein delta represents the moving direction of the terminal equipment; when the terminal equipment approaches to the wireless basic equipment along the z-axis of the tunnel, delta is 1; conversely, δ is-1; v representsThe moving speed of the terminal equipment along the z-axis direction of the tunnel; when T is a negative number, the antenna polarization parameter configuration of the wireless device remains unchanged; otherwise, after a T period, re-executing the steps b-e to refresh the position of the mobile terminal equipment, further re-dividing the near field area and the far field area, and re-configuring the polarization of the antenna for communication; if the terminal moving speed and direction change, relevant equipment of the wireless network, such as a base station or an edge server, actively informs the wireless basic equipment to refresh the configuration of the antenna polarization, and similarly, the step of re-executing steps b-e is re-executed to refresh the position of the mobile terminal equipment, further re-divide the near field area and the far field area, and re-configure the antenna polarization for communication.
The specific method for dividing the near field area and the far field area of the wireless basic equipment by utilizing the statistical method comprises the following steps:
2.1, establishing a database of 'polarization power difference-distance' of an electromagnetic field of wireless basic equipment to be subjected to coverage optimization, wherein the distance is the distance from an observation point to the wireless basic equipment, and the database reflects a corresponding relation between the polarization power difference and the observation distance;
and 2.2, observing the established database by using software 2.1. Setting the unit observation interval length of the electromagnetic field polarization power difference, starting from the wireless basic equipment, moving the observation interval along the axis of the tunnel, calculating the average value of the difference value delta P of the vertical polarization field power and the horizontal polarization field power in the unit observation interval at different positions, wherein the position of the observation interval is the center of the length of the observation interval, and the longitudinal coordinate is expressed as z0.5；
2.3, find all
The position of the observation interval of (a),
2.4, in the observation interval satisfying the condition of 2.3, the observation interval position farthest from the wireless infrastructure device as a reference is selected, and max (z)0.5) The method comprises the steps that the optimal antenna polarization of wireless communication is estimated, namely the antenna polarization with the lowest path loss of signals can be realized;
and 2.5, dividing a propagation field area of the wireless basic equipment according to an estimation result of the optimal antenna polarization.
The specific steps of establishing an electromagnetic field 'polarization power difference-distance' database are as follows:
a. recording the vertical polarization power (P) received by the receiving antenna every half wavelength passed along the tunnel z-axis for the electromagnetic field from the wireless infrastructurevRepresents, unit: dB) and horizontally polarized power (with P)hRepresents, unit: dB);
acquiring vertical polarization power and horizontal polarization power of an electromagnetic field by a pre-measurement means, or predicting and acquiring by using a wireless channel model in a tunnel;
b. calculating the power P of the vertical polarization field at each observation point, namely starting from the wireless basic equipment and linearly distributed along the z axis of the tunnel, wherein the observation points are separated by half wavelength)vAnd horizontal polarization field power PhPolarization power difference Δ P, Δ P ═ Pv-Ph；
The data range of the "polarization power difference-distance" database is determined as follows: when in the whole measuring field, P ═ Pv-PhIs less than 0, the database stops data logging.
Using formulas
Determining the length of a unit observation interval, moving the observation interval along the axis of the tunnel from the wireless basic equipment, and calculating the average value of the polarization power difference delta P in the unit observation interval at different positions
Wherein z isTThe length of a pseudo period of the electromagnetic signal fluctuating along the direction of the z axis of the tunnel; z is a radical ofvThe position of the v-th minimum value of the fluctuation of the field power difference delta P along the direction of the z axis of the tunnel; v is the total minimum value of the fluctuation of delta P along the z-axis direction of the tunnel, the position of an observation interval is the center of the length of the observation interval, and the longitudinal coordinate is expressed as z0.5。
Searching for the farthest position max (z) of the observation interval0.5) The following conditions should be satisfied: in the interval z e 0,max(z0.5)]the average value of Δ P is less than 0; in other intervals, the average value of Δ P is greater than 0; if there is max (z) satisfying the above condition0.5) Then, in the interval z ∈ [2z ]0-max(z0.5)，max(z0.5)]The optimal antenna polarization is vertical polarization; in the interval z ∈ [ - ∞,2z0-max(z0.5)]∪[max(z0.5),+∞]The optimal antenna polarization is horizontal polarization; if there is no max (z) satisfying the above condition0.5) Then the optimum antenna polarization is always horizontal with reference to the entire propagation field of the wireless infrastructure.
When the optimal antenna polarization of the wireless communication is always horizontal polarization in the whole propagation field area of the reference wireless basic equipment, the propagation field area of the wireless basic equipment does not need to be divided; conversely, the propagation field area of the wireless basic equipment is divided into a near field area and a far field area, and the dividing point of the two field areas is set as zDV＝2z0-max(z0.5)；max(z0.5) Wherein z ∈ [2z ]0-max(z0.5)，max(z0.5)]The region of (A) is a near field region; z ∈ [ - ∞,2 z)0-max(z0.5)]∪[max(z0.5),+∞]The region of (a) is the far field region.
Has the advantages that: due to the adoption of the technical scheme, the method has the advantages that: the wireless basic equipment can accurately divide a propagation field area of electromagnetic waves, and further adaptively configures optimal antenna polarization parameters for wireless communication in real time, so that terminal equipment can obtain wireless communication quality with high energy efficiency at any position. The scheme makes full use of the field intensity change rule of the electromagnetic waves in the tunnel, and can obviously improve the coverage performance of the wireless basic equipment without complex system software and hardware design.
Drawings
FIG. 1 is a flow chart of a wireless device coverage optimization method for a tunnel environment based on statistical field division according to the present invention;
FIG. 2 is a flow chart of the wireless infrastructure transmission field area division of the method for optimizing the coverage of the wireless infrastructure equipment for the tunnel environment based on the statistical field division of the present invention;
FIG. 3 illustrates a wireless infrastructure device and a terminal deployed in a tunnel according to the present invention;
FIG. 4 is a schematic diagram of the power distribution of the electromagnetic wave propagating along the (0,0.06, z) direction according to the present invention;
FIG. 5 is a distribution diagram of the polarization power difference of the electromagnetic wave propagating along the (0,0.06, z) direction according to the present invention;
FIG. 6 is a graph showing the average polarization power difference between unit observation areas used in the wireless device coverage optimization method for a tunnel environment based on statistical field division according to the present invention;
fig. 7 is a schematic view of a comprehensive flow of the method for optimizing coverage of a wireless device for a tunnel environment based on statistical field division according to the present invention.
Detailed description of the preferred embodiments
Embodiments of the present application are further described below with reference to the accompanying drawings:
as shown in fig. 1, the wireless coverage optimization object of the present invention is a wireless infrastructure device (e.g., a base station, an access node, a relay node, a sink node, etc.) that communicates in a peer-to-peer manner. The base station of the network where the wireless equipment is located can provide positioning information, inertial navigation information and speed information of terminal equipment (such as mobile phones, wireless sensor nodes, wearable equipment and the like). The wireless basic device comprises a horizontal and vertical dual-polarized antenna module, a propagation field partitioning module, an antenna polarization selection module, a clock period module, a signal transmitting module and a signal receiving module. The terminal equipment comprises a horizontal and vertical dual-polarized antenna module, an antenna polarization selection module, a signal transmitting module and a signal receiving module.
As shown in fig. 2, fig. 3 and fig. 7, the method for optimizing coverage of wireless devices in a tunnel environment based on statistical field division of the present invention is applicable to a wireless infrastructure device in a networking coverage wireless network in a tunnel: such as a base station, a micro base station, a wireless access node, a relay node, and a server for storing data, a mobile terminal device is arranged in a wireless network area;
the method comprises the following steps:
a, firstly, setting a Cartesian coordinate system in a tunnel, and setting the origin of the coordinate systemThe point is located at the center of the tunnel, the x, y and z axes are respectively used for respectively following the width direction, the height direction and the length direction of the tunnel, and the antenna coordinate of the wireless basic device is known and recorded as (x)0,y0,z0)；
b, acquiring information of all mobile terminal devices in the tunnel through the server: comprising location information (x) of a mobile terminal device1, y1,z1) Information on the moving direction and the moving speed;
c, the wireless basic equipment divides the near field area and the far field area by using a statistical method, and the vertical coordinate of the position of the dividing point of the divided near field area and far field area is expressed as zDV；
If the propagation field area of the wireless basic equipment is not divided into a near field area and a far field area, the wireless basic equipment and the mobile terminal equipment both select a horizontal polarization antenna to send and receive signals;
if the ordinate z of the mobile terminal device1∈[z0-zDV,z0+zDV]If so, judging that the mobile terminal equipment is positioned in a near field area of the wireless basic equipment, and switching the wireless basic equipment to a vertical polarization antenna; if the ordinate z of the wireless infrastructure is1∈[-∞,z0-zDV]∪[z0+zDV,+∞]If the mobile terminal equipment is located in the far field area of the wireless basic equipment, the wireless basic equipment is switched to the horizontal polarization antenna for communication; and then sending a parameter configuration command to the mobile terminal equipment, and commanding the mobile terminal equipment to also adopt the same antenna polarization for communication:
d, configuring antenna polarization parameters of the wireless basic equipment and the mobile terminal equipment:
e if the wireless communication between the wireless infrastructure equipment and the mobile terminal equipment is not ended and the terminal moving speed and direction are not changed, the wireless infrastructure equipment utilizes
Determining a refreshing period of the antenna polarization parameter, wherein delta represents the moving direction of the terminal equipment; when the terminal equipment approaches to the wireless basic equipment along the z-axis of the tunnel, delta is 1(ii) a Conversely, δ is-1; v represents the moving speed of the terminal equipment along the z-axis direction of the tunnel; when T is a negative number, the antenna polarization parameter configuration of the wireless device remains unchanged; otherwise, after a T period, re-executing the steps b-e to refresh the position of the mobile terminal equipment, further re-dividing the near field area and the far field area, and re-configuring the polarization of the antenna for communication; if the terminal moving speed and direction change, relevant equipment of the wireless network, such as a base station or an edge server, actively informs the wireless basic equipment to refresh the configuration of the antenna polarization, and similarly, the step of re-executing steps b-e is re-executed to refresh the position of the mobile terminal equipment, further re-divide the near field area and the far field area, and re-configure the antenna polarization for communication.
The specific method for dividing the near field area and the far field area of the wireless basic equipment by utilizing the statistical method comprises the following steps:
2.1, establishing a database of 'polarization power difference-distance' of an electromagnetic field of wireless basic equipment to be subjected to coverage optimization, wherein the distance is the distance from an observation point to the wireless basic equipment, and the database reflects the corresponding relation between the polarization power difference and the distance;
and 2.2, observing the established database by using software 2.1. Setting the unit observation interval length of the electromagnetic field polarization power difference, starting from the wireless basic equipment, moving the observation interval along the axis of the tunnel, calculating the average value of the difference value delta P of the vertical polarization field power and the horizontal polarization field power in the unit observation interval at different positions, wherein the position of the observation interval is the center of the length of the observation interval, and the longitudinal coordinate is expressed as z0.5；
2.3, find all
The position of the observation interval of (a),
2.4, in the observation interval satisfying the condition of 2.3, the observation interval position farthest from the wireless infrastructure device as a reference is selected, and max (z)0.5) The method comprises the steps that the optimal antenna polarization of wireless communication is estimated, namely the antenna polarization with the lowest path loss of signals can be realized;
and 2.5, dividing a propagation field area of the wireless basic equipment according to an estimation result of the optimal antenna polarization.
The specific steps of establishing an electromagnetic field 'polarization power difference-distance' database are as follows:
a. recording the vertical polarization power (P) received by the receiving antenna every half wavelength passed along the tunnel z-axis for the electromagnetic field from the wireless infrastructurevRepresents, unit: dB) and horizontally polarized power (with P)hRepresents, unit: dB);
acquiring vertical polarization power and horizontal polarization power of an electromagnetic field by a pre-measurement means, or predicting and acquiring by using a wireless channel model in a tunnel;
b. calculating the power P of the vertical polarization field at each observation point, namely starting from the wireless basic equipment and linearly distributed along the z axis of the tunnel, wherein the observation points are separated by half wavelength)vAnd horizontal polarization field power PhPolarization power difference Δ P, Δ P ═ Pv-Ph；
The data range of the "polarization power difference-distance" database is determined as follows: when in the whole measuring field, P ═ Pv-PhIs less than 0, the database stops data logging.
Using formulas
Determining the length of a unit observation interval, moving the observation interval along the axis of the tunnel from the wireless basic equipment, and calculating the average value of the polarization power difference delta P in the unit observation interval at different positions
Wherein z isTThe length of a pseudo period of the electromagnetic signal fluctuating along the direction of the z axis of the tunnel; z is a radical ofvThe position of the v-th minimum value of the fluctuation of the field power difference delta P along the direction of the z axis of the tunnel; v is the total minimum value of the fluctuation of delta P along the z-axis direction of the tunnel, the position of an observation interval is the center of the length of the observation interval, and the longitudinal coordinate is expressed as z0.5。
Searching for the farthest position max (z) of the observation interval0.5) Should satisfy the followingA piece: in the interval z ∈ [0, max (z)0.5)]The average value of Δ P is less than 0; in other intervals, the average value of Δ P is greater than 0; if there is max (z) satisfying the above condition0.5) Then, in the interval z ∈ [2z ]0-max(z0.5)，max(z0.5)]The optimal antenna polarization is vertical polarization; in the interval z ∈ [ - ∞,2z0-max(z0.5)]∪[max(z0.5),+∞]The optimal antenna polarization is horizontal polarization; if there is no max (z) satisfying the above condition0.5) Then the optimum antenna polarization is always horizontal with reference to the entire propagation field of the wireless infrastructure.
When the optimal antenna polarization of the wireless communication is always horizontal polarization in the whole propagation field area of the reference wireless basic equipment, the propagation field area of the wireless basic equipment does not need to be divided; conversely, the propagation field area of the wireless basic equipment is divided into a near field area and a far field area, and the dividing point of the two field areas is set as zDV＝2z0-max(z0.5)；max(z0.5) Wherein z ∈ [2z ]0-max(z0.5)，max(z0.5)]The region of (A) is a near field region; z ∈ [ - ∞,2 z)0-max(z0.5)]∪[max(z0.5),+∞]The region of (a) is the far field region.
FIG. 5 is a diagram illustrating the distribution of the polarization power difference of the electromagnetic wave propagating along the (0,0.06, z) direction according to the present invention;
the specific embodiment is as follows:
step 1: establishing an electromagnetic field 'polarized power difference-distance' database of the wireless basic equipment;
a. recording the vertical polarization power (P) received by the receiving antenna every half wavelength passed along the tunnel z-axis for the electromagnetic field from the wireless infrastructurevRepresents, unit: dB) and horizontally polarized power (with P)hRepresents, unit: dB);
the vertical polarization power and the horizontal polarization power of the electromagnetic field can be obtained by means of pre-measurement, and can also be obtained by means of wireless channel model prediction in a tunnel, such as a multi-wave mode model, a ray model and the like;
b. calculating the power of the vertical polarization field at each observation pointAnd the difference of the horizontal polarization field power, expressed as Δ P, where Δ P is Pv-Ph。
The data range of the "polarization power difference-distance" database is determined as follows: when in the whole measuring field, P ═ Pv-PhIs less than 0, the database stops data logging.
Step 2: using formulas
Determining the length of a unit observation interval; moving observation intervals along the axis of the tunnel from the wireless basic equipment, calculating the average value of delta P in the unit observation intervals at different positions, and using the average value
Represents; wherein z isTThe length of a pseudo period of the electromagnetic signal fluctuating along the direction of the z axis of the tunnel; z is a radical ofvThe position of the v-th minimum value of the fluctuation of the field power difference delta P along the direction of the z axis of the tunnel; v is the total number of minimum values of fluctuation of the delta P along the z-axis direction of the tunnel. The position of the observation interval is the center of its length, and the longitudinal coordinate is expressed as z0.5；
And 3, step 3: find out all
The observation interval position of (2).
And 4, step 4: in the observation interval satisfying the condition of step 3, the position of the observation interval farthest from the wireless base device is selected, and max (z) is used0.5) Represents; an optimal antenna polarization for wireless communication is estimated (optimal polarization refers to the antenna polarization that achieves the lowest path loss for the signal).
Position max (z)0.5) The following conditions should be satisfied: in the interval z ∈ [ z ]0，max(z0.5)]The average value of Δ P is less than 0; in other intervals, the average value of Δ P is greater than 0. If there is max (z) satisfying the above condition0.5) Then, in the interval z ∈ [2z ]0-max(z0.5)，max(z0.5)]The optimal antenna polarization is vertical polarization; in the interval z ∈ [ - ∞,2z0-max(z0.5)]∪[max(z0.5),+∞]The optimal antenna polarization is horizontal polarization; if there is no max (z) satisfying the above condition0.5) Then, in the whole propagation field area of the wireless basic device, the optimal antenna polarization is always horizontal polarization;
and 5, step 5: according to the estimation result of the optimal antenna polarization, dividing a propagation field area of the wireless basic equipment:
when the optimal antenna polarization of wireless communication is always horizontal polarization in the whole propagation field area of the wireless basic equipment, the propagation field area of the wireless basic equipment does not need to be divided; conversely, the propagation field region of the wireless infrastructure is divided into a near field region and a far field region. The boundary position of the two field regions is zDV＝max(z0.5)-z0. Wherein z ∈ [ z ]0-zDV,z0+zDV]The region of (A) is a near field region; z ∈ [ - ∞, z)0-zDV]∪[z0+zDV,+∞]The region of (a) is the far field region.
As shown in fig. 4, the present embodiment employs a channel model in (y.huo, l.zhao, q.s.hu, e.j.ding, x.h.zhao, and z.sun. "Optimal deployment of antenna for field coverage in the field networks", IEEE Access, vol.8, No.1, pp.2169-3536,2020.) to predict the electromagnetic field of the wireless infrastructure in the roadway. Fig. 4 is a measured power distribution of the electromagnetic wave propagating along (0,0.06, z).
a3. the data range of the "polarization power difference-distance" database is determined as follows: when in the whole measuring field, P ═ Pv-PhIs less than 0, the database stops data logging.
In the present embodiment, when the measurement field range is 0 to 557.87m, Δ P ═ Pv-PhThe average of "polarized power difference-distance" database stops data recording.
b. Using formulas
Determining the length of a unit observation interval; moving observation interval along tunnel axis from wireless basic equipmentCalculating the average value of delta P in unit observation interval at different positions, and using
Represents; wherein z isTThe length of a pseudo period of the electromagnetic signal fluctuating along the direction of the z axis of the tunnel; z is a radical ofvThe position of the v-th minimum value of the fluctuation of the field power difference delta P along the direction of the z axis of the tunnel; v is the total number of minimum values of fluctuation of the delta P along the z-axis direction of the tunnel. The position of the observation interval is the center of its length, and the longitudinal coordinate is expressed as z0.5；
In this embodiment, the formula
Obtaining the length of a unit observation interval as 70.33 m; and starting from the wireless basic equipment, moving the observation interval along the axis of the tunnel, calculating the average value of delta P in the unit observation interval at different positions, and obtaining a prediction result shown in figure 6.
c. Find out all
The observation interval position of (2).
In the present embodiment, the first and second electrodes are,
has only one observation interval position, z0.5＝247.90m；
d. In the observation interval satisfying the condition c, the observation interval position farthest from the wireless base device is selected and max (z)0.5) Represents; an optimal antenna polarization for wireless communication is estimated (optimal polarization refers to the antenna polarization that achieves the lowest path loss for the signal).
Position max (z)0.5) The following conditions should be satisfied: in the interval z ∈ [0, max (z)0.5)]The average value of Δ P is less than 0; in other intervals, the average value of Δ P is greater than 0. If there is max (z) satisfying the above condition0.5) Then, in the interval z ∈ [2z ]0-max(z0.5)，max(z0.5)]The optimal antenna polarization is vertical polarization; in the interval z ∈ [ - ∞,2z0-max(z0.5)]∪[max(z0.5),+∞]The optimal antenna polarization is horizontal polarization; if there is no max (z) satisfying the above condition0.5) Then, in the whole propagation field area of the wireless basic device, the optimal antenna polarization is always horizontal polarization;
in this embodiment, max (z)0.5) 247.90 m; in the interval z ∈ [0m,247.90m]，ΔPIs less than 0; in other intervals, the average value of Δ P is greater than 0. In the interval z e [ -247.90m,247.90m]The optimal antenna polarization is vertical polarization; in the interval z ∈ [ - ∞, -247.90m]∪[247.90m,+∞]The optimal antenna polarization is horizontal polarization;
e. according to the estimation result of the optimal antenna polarization, dividing a propagation field area of the wireless basic equipment:
when the optimal antenna polarization of wireless communication is always horizontal polarization in the whole propagation field area of the wireless basic equipment, the propagation field area of the wireless basic equipment does not need to be divided; conversely, the propagation field region of the wireless infrastructure is divided into a near field region and a far field region. The boundary position of the two field regions is zDV＝max(z0.5)-z0. Wherein z ∈ [ z ]0-zDV,z0+zDV]The region of (A) is a near field region; z ∈ [ - ∞, z)0-zDV]∪[z0+zDV,+∞]The region of (a) is the far field region.
In the embodiment, a propagation field area of the wireless basic equipment is divided into a near field area and a far field area; the position of the dividing point of the two field regions is zDV＝247.90m。
Wherein, the area of z ∈ [ -247.90m,247.90m ] is a near field region; the region where z ∈ [ - ∞, -247.90m ]. U [247.90m, + ∞ ] is the far field region.
And 3, step 3: configuring antenna polarization parameters of wireless basic equipment and terminal equipment:
if the propagation field area of the wireless basic equipment is not divided in the step 2, the antenna polarization selection modules of the wireless basic equipment and the terminal equipment select a horizontal polarization antenna to send and receive signals;
if the propagation field of the wireless infrastructure is divided, when z1∈[z0-zDV,z0+zDV]If the terminal is located in the near field area of the wireless basic device, the antenna polarization selection module of the wireless basic device is switched to the vertical polarization antenna; when z is1∈[-∞,z0-zDV]∪[z0+zDV,+∞]If the terminal is located in the far field area of the wireless basic equipment, the antenna polarization selection module of the wireless basic equipment is switched to the horizontal polarization antenna for communication; and then sending a parameter configuration command to the terminal, and commanding an antenna polarization selection module of the terminal to communicate by adopting the same antenna polarization.
In this example, z1＝60m∈[-247.90m,247.90m]And the terminal can be judged to be in the near field area of the wireless basic equipment, and the antenna polarization selection modules of the wireless basic equipment and the terminal are switched to the vertical polarization antenna for communication.
Step 4, if the wireless communication is not finished, the clock period module of the wireless basic device utilizes
Determining a refresh period of the antenna polarization parameters; wherein δ represents the moving direction of the terminal equipment, and δ is 1 when the terminal equipment approaches the wireless foundation equipment along the z-axis of the tunnel; conversely, δ is-1; v represents the moving speed of the terminal equipment along the z-axis direction of the tunnel. When T is a negative number, the antenna polarization parameter configuration of the wireless device remains unchanged; otherwise, after a period of T, steps 1-4 are re-executed.
In this embodiment, the refresh period of the antenna polarization parameter of the wireless infrastructure is
If the wireless communication has not ended and the infrastructure has not received the displacement information update notification about the terminal, steps 1-4 will be re-executed after 187.90 s.
Claims (6)
1. A wireless device coverage optimization method for a tunnel environment based on statistical method field division is characterized in that: a wireless infrastructure device adapted for intra-tunnel networking overlay wireless networks: such as a base station, a micro base station, a wireless access node, a relay node, and a server for storing data, a mobile terminal device is arranged in a wireless network area;
the method comprises the following steps:
a, firstly, setting a Cartesian coordinate system in a tunnel, wherein the origin of the coordinate system is positioned at the center of the tunnel, the x axis, the y axis and the z axis are respectively used for respectively following the width direction, the height direction and the length direction of the tunnel, and the antenna coordinate of the wireless basic equipment is known and recorded as (x)0,y0,z0)；
b, acquiring information of all mobile terminal devices in the tunnel through the server: comprising location information (x) of a mobile terminal device1,y1,z1) Information on the moving direction and the moving speed;
c, the wireless basic equipment divides the near field area and the far field area by using a statistical method, and the vertical coordinate of the position of the dividing point of the divided near field area and far field area is expressed as zDV；
If the propagation field area of the wireless basic equipment is not divided into a near field area and a far field area, the wireless basic equipment and the mobile terminal equipment both select a horizontal polarization antenna to send and receive signals;
if the ordinate z of the mobile terminal device1∈[z0-zDV,z0+zDV]If so, judging that the mobile terminal equipment is positioned in a near field area of the wireless basic equipment, and switching the wireless basic equipment to a vertical polarization antenna; if the ordinate z of the wireless infrastructure is1∈[-∞,z0-zDV]∪[z0+zDV,+∞]If the mobile terminal equipment is located in the far field area of the wireless basic equipment, the wireless basic equipment is switched to a horizontal polarization antenna for communication; and then sending a parameter configuration command to the mobile terminal equipment, and commanding the mobile terminal equipment to also adopt the same antenna polarization for communication:
d, configuring antenna polarization parameters of the wireless basic equipment and the mobile terminal equipment:
e if the wireless communication between the wireless infrastructure equipment and the mobile terminal equipment is not finished and the terminal moving speed and directionWithout change, the wireless infrastructure device utilizes
Determining a refreshing period of antenna polarization parameters, wherein delta represents the moving direction of the terminal equipment; when the terminal equipment approaches to the wireless basic equipment along the z-axis of the tunnel, delta is 1; conversely, δ is-1; v represents the moving speed of the terminal equipment along the z-axis direction of the tunnel; when T is a negative number, the antenna polarization parameter configuration of the wireless device remains unchanged; otherwise, after a T period, re-executing the steps b-e, refreshing the position of the mobile terminal equipment, further re-dividing the near field area and the far field area, and re-configuring the polarization of the antenna for communication; if the terminal moving speed and direction change, relevant equipment of the wireless network, such as a base station or an edge server, actively informs wireless basic equipment to refresh the configuration of antenna polarization, and also re-executes the steps of re-executing the steps b-e to refresh the position of the mobile terminal equipment, further re-divide the near field area and the far field area, and re-configure the antenna polarization for communication.
2. The method for optimizing coverage of wireless equipment for tunnel environment based on statistical field division according to claim 1, wherein the specific method for dividing the near field and the far field of the wireless infrastructure equipment by using the statistical method is as follows:
2.1, establishing a database of an electromagnetic field' polarization power difference-distance of wireless basic equipment to be subjected to coverage optimization, wherein the distance is the distance from an observation point to the wireless basic equipment, and the database reflects the corresponding relation between the polarization power difference and the observation distance;
and 2.2, observing the established database by using software 2.1. Setting the unit observation interval length of the electromagnetic field polarization power difference, starting from the wireless basic equipment, moving the observation interval along the axis of the tunnel, calculating the average value of the difference value delta P of the vertical polarization field power and the horizontal polarization field power in the unit observation interval at different positions, wherein the position of the observation interval is the center of the length of the observation interval, and the longitudinal coordinate is expressed as z0.5；
2.3. Find out all
The position of the observation interval of (a),
2.4, in the observation interval satisfying the condition of 2.3, the observation interval position farthest from the wireless infrastructure device as a reference is selected, and max (z)0.5) The method comprises the steps that the optimal antenna polarization of wireless communication is estimated, namely the antenna polarization with the lowest signal path loss can be realized;
and 2.5, dividing a propagation field area of the wireless basic equipment according to an estimation result of the optimal antenna polarization.
3. The method for optimizing coverage of wireless equipment in a tunnel environment based on statistical field division as claimed in claim 2, wherein the step of establishing the electromagnetic field "polarized power difference-distance" database comprises the following steps:
a. recording the vertical polarization power (P) received by the receiving antenna every half wavelength passed along the tunnel z-axis for the electromagnetic field from the wireless infrastructurevRepresents, unit: dB) and horizontally polarized power (with P)hRepresents, unit: dB);
acquiring vertical polarization power and horizontal polarization power of an electromagnetic field by means of pre-measurement, or predicting and acquiring by using a wireless channel model in a tunnel;
b. calculating the power P of the vertical polarization field at each observation point, namely starting from the wireless basic equipment and linearly distributed along the z axis of the tunnel, wherein the observation points are separated by half wavelength)vAnd horizontal polarization field power PhPolarization power difference Δ P, Δ P ═ Pv-Ph；
The data range of the "polarization power difference-distance" database is determined as follows: when in the whole measuring field, P ═ Pv-PhIs less than 0, the database stops data logging.
4. Method for wireless device coverage optimization for tunnel environments based on statistical field partitioning, according to claim 2, characterized in that it usesFormula (II)
Determining the length of a unit observation interval, moving the observation interval along the axis of the tunnel from the wireless basic equipment, and calculating the average value of the polarization power difference delta P in the unit observation interval at different positions
Wherein z isTThe length of a pseudo period of the electromagnetic signal fluctuating along the direction of the z axis of the tunnel; z is a radical ofvThe position of the v-th minimum value of the fluctuation of the field power difference delta P along the direction of the z axis of the tunnel; v is the total minimum value of the fluctuation of delta P along the z-axis direction of the tunnel, the position of an observation interval is the center of the length of the observation interval, and the longitudinal coordinate is expressed as z0.5。
5. Method for optimizing the coverage of a wireless device for a tunnel environment based on the statistical field partitioning according to claim 2, characterized in that the farthest position max (z) of the observation interval is searched0.5) The following conditions should be satisfied: in the interval z ∈ [0, max (z)0.5)]The average value of Δ P is less than 0; in other intervals, the average value of Δ P is greater than 0; if there is max (z) satisfying the above condition0.5) Then, in the interval z ∈ [2z ]0-max(z0.5)，max(z0.5)]The optimal antenna polarization is vertical polarization; in the interval z ∈ [ - ∞,2z0-max(z0.5)]∪[max(z0.5),+∞]The optimal antenna polarization is horizontal polarization; if there is no max (z) satisfying the above condition0.5) Then the optimum antenna polarization is always horizontal with reference to the entire propagation field of the wireless infrastructure.
6. The method of claim 2, wherein when the optimal antenna polarization for wireless communication is always horizontal polarization in the entire propagation field of the reference wireless infrastructure, the propagation field of the reference wireless infrastructure does not need to be divided; on the contrary, the propagation field of the wireless basic equipment is dividedIs divided into a near field region and a far field region, and the boundary point of the two field regions is set as zDV＝2z0-max(z0.5)；max(z0.5) Wherein z ∈ [2z ]0-max(z0.5)，max(z0.5)]The region of (A) is a near field region; z ∈ [ - ∞,2 z)0-max(z0.5)]∪[max(z0.5),+∞]The region of (a) is the far field region.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011353454.9A CN112770328A (en) | 2020-11-27 | 2020-11-27 | Statistical method field division-based wireless equipment coverage optimization method for tunnel environment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011353454.9A CN112770328A (en) | 2020-11-27 | 2020-11-27 | Statistical method field division-based wireless equipment coverage optimization method for tunnel environment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112770328A true CN112770328A (en) | 2021-05-07 |
Family
ID=75693334
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011353454.9A Pending CN112770328A (en) | 2020-11-27 | 2020-11-27 | Statistical method field division-based wireless equipment coverage optimization method for tunnel environment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112770328A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109149125A (en) * | 2018-08-30 | 2019-01-04 | 西南交通大学 | A kind of phased array antenna system and its optimization method suitable for tunnel environment |
-
2020
- 2020-11-27 CN CN202011353454.9A patent/CN112770328A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109149125A (en) * | 2018-08-30 | 2019-01-04 | 西南交通大学 | A kind of phased array antenna system and its optimization method suitable for tunnel environment |
Non-Patent Citations (2)
| Title |
|---|
| HUO YU等: "Optimization of Wireless Communication Coverage in Underground Tunnels Based on Zone Division", 《INTERNATIONAL JOURNAL OF ANTENNAS AND PROPAGATION》 * |
| YU HUO等: "Optimal Deployment of Antenna for Field Coverage in Coal Mine Tunnels", 《IEEE ACCESS》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Jameel et al. | Propagation channels for mmWave vehicular communications: State-of-the-art and future research directions | |
| Giordani et al. | Millimeter wave communication in vehicular networks: Challenges and opportunities | |
| US8200242B2 (en) | Enhanced wireless node location using differential signal strength metric | |
| US7116988B2 (en) | Location of wireless nodes using signal strength weighting metric | |
| KR100994840B1 (en) | Position determination method and system based on wlan rssi value | |
| CN105338489B (en) | A kind of intelligent terminal and bluetooth indoor locating system for indoor positioning | |
| US7626969B2 (en) | Relative location of a wireless node in a wireless network | |
| CN111865446B (en) | Intelligent beam registration method and device realized by using context information of network environment | |
| JPWO2005088868A1 (en) | Radio wave propagation characteristic estimation system, method and program | |
| CN101977423A (en) | Method for selecting access point by vehicle-mounted WiFi (Wireless Fidelity) equipment | |
| WO2010113379A1 (en) | Radio wave state measurement system, radio wave state measurement method, and storage medium in which radio wave state measurement program is stored | |
| CN101818653A (en) | Received signal strength based real-time location method for people under mine | |
| Celaya-Echarri et al. | Building decentralized fog computing-based smart parking systems: from deterministic propagation modeling to practical deployment | |
| Janssen et al. | A primer on real-world RSS-based outdoor NB-IoT localization | |
| CN112866904A (en) | Channel-training-free large-dimension communication beam alignment method based on beam index map | |
| Suchanski et al. | Radio environment maps for military cognitive networks: construction techniques vs. map quality | |
| Dieng et al. | Comparing and adapting propagation models for LoRa networks | |
| CN113993180A (en) | Base station based on minimized multiplicative path loss and intelligent reflecting surface selection method | |
| Hilmani et al. | Hierarchical protocol based on recursive clusters for smart parking applications using Internet of things (IOT) | |
| CN112770328A (en) | Statistical method field division-based wireless equipment coverage optimization method for tunnel environment | |
| CN114363808B (en) | Indoor positioning method based on RSSI ranging | |
| JP2003348637A (en) | Mobile communication system | |
| KR101744306B1 (en) | Wireless network planning system and method considering radio wave environment, and terminal unit thereof | |
| CN112770332A (en) | Wireless equipment coverage optimization method for tunnel environment based on multi-wave mode field division | |
| KR102057290B1 (en) | Method and apparatus for estimating antenna orientation of base station |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20210507 |
|
| WD01 | Invention patent application deemed withdrawn after publication |