CN103269494A - Method and system for interruption compensating in wireless access network cell - Google Patents

Abstract

The invention discloses a method and system for interruption compensating in a wireless access network cell. The method includes the steps that S1, network information data are collected and monitored, and whether network interruption occurs or not in the cell is judged according to the network information data; S2, if cell network interruption occurs, whether the interruption compensating is needed to be carried out or not is judged; S3, when the interruption cell needs the interruption compensating, aiming at the terminal cell, an area coverage rate and coverage overlapping are optimized, and a particle swarm optimization algorithm is used for obtaining an optimization scheme; S4, the optimization scheme is implemented, and the network information data are collected and monitored after the optimization. According to the method and system for the interruption compensating in the wireless access network cell, the area coverage rate and coverage overlapping of the interruption cell are optimized by the adoption of the particle swarm optimization algorithm, the automatic interruption compensating of the interruption cell is achieved, the speed of the interruption compensating is improved, human interference with network operation is reduced to the maximum, and network operation efficiency is improved effectively.

Description

Method and system for compensating interruption of wireless access network cell

Technical Field

The present invention relates to the field of maintenance of wireless access networks, and in particular, to a method and a system for compensating for interruption in a wireless access network cell.

Background

With the rapid development of communication technology and the increase of the demand of people for communication intelligence, ad hoc networks have become one of the important directions for the development of network technology. In order to reduce the network operation cost to the maximum, providing the self-organizing function is one of the main targets of LTE (Long Term Evolution). The self-organizing network mainly has three functions, namely self-configuration, self-optimization and self-healing. The self-healing function means that the network can automatically detect and recover the cell fault, thereby greatly reducing the labor and material cost required by fault detection and processing. An important aspect of self healing is cell outage management, including both cell outage detection and cell outage compensation scenarios. In the mobile cellular network, the base station suddenly fails due to software and hardware faults, sudden power failure, configuration errors and the like, so that the communication of the cell is interrupted. How to compensate the interruption of the interruption cell becomes a current research focus, and the aim of the research focus is that under the environment without manual operation, the system can automatically recover from low performance and even interruption state in time.

The invention discloses a cell interruption compensation method for an ad hoc network in Chinese patent with application number 201210331124.9, relating to a cell interruption compensation method for an ad hoc network, belonging to the technical field of 4G communication, and comprising the following steps: selecting an internal compensation cell and an external compensation cell from adjacent cells, and determining an adjustment parameter of the compensation cell; sequentially adjusting parameters of the internal compensation cell, obtaining the increment of an internal compensation performance function according to the information reported by the user, and updating the parameters; performing an external adjustment stage after internal adjustment iteration is stopped; sequentially adjusting the parameters of the external compensation cell, obtaining the increment of an external compensation performance function according to the information reported by the user, and updating the parameters; the compensation is ended when the external adjustment iteration stops. The invention can automatically and effectively compensate the user performance of the interrupted cell after detecting the interruption of the cell, but the optimization of the interruption network compensation in the execution process of the method is incomplete, and the compensation needs to be realized through multiple iterations, which consumes long time and can not recover the network from the interruption state in time.

Disclosure of Invention

Technical problem to be solved

The technical problem to be solved by the invention is as follows: how to provide a wireless access network cell interruption compensation method and system, which can realize the automatic compensation of cell network interruption and improve the speed of interruption compensation and the compensation effect.

(II) technical scheme

In order to solve the above technical problem, the present invention provides a method for compensating for interruption of a radio access network cell, comprising the steps of:

s1, collecting and monitoring network information data, and judging whether network interruption occurs in the cell according to the network information data;

s2, if the network of the cell is interrupted, judging whether the interrupted cell needs to be interrupted for compensation;

s3, when the interruption cell needs interruption compensation, optimizing the area coverage rate and coverage overlap aiming at the terminal cell, and obtaining an optimization scheme by utilizing a particle swarm optimization algorithm;

s4, implementing the optimization scheme, and collecting and monitoring network information data after the optimization is completed.

Preferably, the network information data includes a reception power, a reception quality of the mobile subscriber, a traffic load of the cell, and a service type of the subscriber.

Preferably, in step S2, it is determined whether the cell with the outage needs to perform outage compensation according to a coverage index of the network.

Preferably, the wireless access network is an LTE network in an urban environment, and the coverage index satisfies:

the user equipment measures the receiving power value of the main cell to be more than-105 dBm;

the user equipment measures the reception quality value of the primary cell to be greater than-13.8 dB.

The signal to interference and noise ratio of the reference signal received by the user equipment supports the lowest modulation and coding scheme.

Preferably, the method for optimizing area coverage and coverage overlap for the terminal cell in step S3 includes the steps of:

s311, calculating reference signal coverage areas of neighbor cells of the terminal cell respectively by taking the reference signal as a reference, wherein the reference signal coverage areas of the neighbor cells are as follows:

$S\left(p_{\mathrm{RS}}^i\right)=\mathrm{\π}\·{\left(g^{-1}\left({\mathrm{PL}}_{\max }^i\right)\right)}^2$

wherein,

is the reference signal coverage area of the neighbor cell,

for the propagation model of the neighbour cell,

the maximum allowable path loss of the neighbor cell is represented by i belonging to n, and n is the number of the neighbor cells;

s312 obtains a coverage rate of the reference signal in the whole area by using the coverage area of the reference signal in the neighbor cell, where the coverage rate of the reference signal in the whole area is:

$f_{\mathrm{cov}}=100\·\frac{S\left(p_{\mathrm{RS}}^1\right)\∪S\left(p_{\mathrm{RS}}^2\right)\∪\·\·\·\∪S\left(p_{\mathrm{RS}}^n\right)}{S_{t\arg \mathrm{et}}}$

wherein f is_covFor the coverage of the whole area reference signal, S_targetTarget coverage areas for n neighbor cells;

s313, obtaining a coverage overlapping rate of the reference signal of the whole area by using the reference signal coverage area of the neighbor cell, where the whole area includes the reference signal coverage areas of the outage cell and the neighbor cell, and the coverage overlapping rate of the reference signal of the whole area is:

$f_{\mathrm{overlap}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\underset{j,k\∈n,j,k\≠i}{\overset{n}{\mathrm{\Σ}}}S\left(p_{\mathrm{RS}}^i\right)\∩S\left(p_{\mathrm{RS}}^j\right)\∩S\left(p_{\mathrm{RS}}^k\right)}{S_{t\arg \mathrm{et}}}$

wherein f is_overlapThe coverage overlap ratio of the reference signal is the whole area.

S314 simultaneously optimizing the coverage rate and the coverage overlap, wherein the optimization function is:

$f_{\mathrm{tot}}=f_{\mathrm{cov}}+k\left(f_{\mathrm{cov}}\right)\·\frac{1}{1+f_{\mathrm{overlap}}}$

wherein, $k\left(f_{\mathrm{cov}}\right)\text{=}\left\{\begin{array}{cc}0,& f_{\mathrm{cov}}<90\\ 100\&CenterDot;{\left(\frac{f_{\mathrm{cov}}-90}{5}\right)}^2,& 90\&le;f_{\mathrm{cov}}<95\\ 100,& \mathrm{else}\end{array}\right.,$ f_totis the optimization function.

Preferably, the method for obtaining the optimization scheme by using the particle swarm optimization algorithm in step S3 includes the steps of:

s321 sets maximum iteration times, each neighbor cell sets a position vector and a velocity vector, and the position vector is X_i=(x_i1,x_i2,…,x_iD) The velocity vector is V_i=(v_i1,v_i2,…,v_iD) D is a vector dimension, and the iteration times, the position vector set by each neighbor cell and the velocity vector are initialized;

s322, substituting the position vector and the velocity vector into the optimization function for calculation, and storing an optimal solution in an iterative process by using an optimal solution set;

s323, adding 1 to the iteration times, and updating the position vector and the velocity vector

$v_{\mathrm{id}}^{t+1}=\mathrm{\&omega;}\&CenterDot;v_{\mathrm{id}}^t+c_1{r}_1(p_{\mathrm{id}}^t-x_{\mathrm{id}}^t)+c_2{r}_2(p_{\mathrm{gd}}^t-x_{\mathrm{id}}^t)$

$x_{\mathrm{id}}^{t+1}=x_{\mathrm{id}}^t+v_{\mathrm{id}}^{t+1}$

Where t is the number of iterations, c₁、c₂As an acceleration factor, r₁、r₂Is [0,1 ]]D is the dimension in D dimension, and omega is the inertia weight factor;

s324, if the current iteration times is less than the maximum iteration times, repeating the steps S322-S324, otherwise, outputting a current optimal solution set, wherein the current optimal solution set is the optimization scheme.

The invention also provides a system for compensating the interruption of the wireless access network cell, which comprises:

the information monitoring module is used for collecting and monitoring network information data and storing the network information data in the information storage module;

the information analysis module is used for analyzing the network information data stored in the information storage module, judging whether network interruption occurs in a cell, judging whether the interrupted cell needs to be subjected to interruption compensation if the network of the cell is interrupted, and sending a compensation request to the compensation planning module if the terminal cell needs to be compensated;

the compensation planning module is used for optimizing the coverage rate and the coverage overlapping of the interrupt cell after receiving the compensation request, obtaining an optimization scheme by utilizing a particle swarm optimization algorithm, storing the optimization scheme into the information storage module and sending an execution request to the scheme execution module;

a scheme execution module, configured to read the optimization scheme of the information storage module after receiving the execution request, and perform interruption compensation on the interruption cell according to the optimization scheme;

and the information storage module is used for storing the network information data and the optimization scheme.

Preferably, the network information data includes a reception power, a reception quality of the mobile subscriber, a traffic load of the cell, and a service type of the subscriber.

Preferably, the compensation planning module sets an optimization function for optimizing the coverage area and the coverage overlap of the outage cell, where the optimization function is:

$f_{\mathrm{tot}}=f_{\mathrm{cov}}+k\left(f_{\mathrm{cov}}\right)\&CenterDot;\frac{1}{1+f_{\mathrm{overlap}}}$

wherein, $k\left(f_{\mathrm{cov}}\right)\text{=}\left\{\begin{array}{cc}0,& f_{\mathrm{cov}}<90\\ 100\&CenterDot;{\left(\frac{f_{\mathrm{cov}}-90}{5}\right)}^2,& 90\&le;f_{\mathrm{cov}}<95\\ 100,& \mathrm{else}\end{array}\right.,$ f_totfor said optimization function, f_covFor the coverage of the whole area reference signal, f_overlapThe coverage overlap ratio of the reference signal for the whole area, which includes the reference signal coverage areas of the outage cell and the neighbor cells.

Preferably, the compensation planning module sets a position vector and a velocity vector for each cell by using a particle swarm optimization algorithm, brings the position vector and the velocity vector into the optimization function to obtain an optimized value, updates the position vector and the velocity vector, and performs optimization iteration to obtain an optimal solution set, where the optimal solution set is the optimization scheme.

(III) advantageous effects

The method and the system for compensating the interruption of the wireless access network cell utilize the network of the cell around the terminal cell, optimize the coverage rate and coverage overlapping of the interruption cell by adopting the particle swarm optimization algorithm, realize the automatic interruption compensation of the interruption cell, improve the speed of the interruption compensation, better reduce the performance loss of users in the interruption cell, furthest reduce the intervention of human to the network operation and effectively improve the network operation efficiency.

Drawings

Fig. 1 is a diagram of method steps of a method for compensating for interruption in a radio access network cell according to an embodiment of the present invention;

fig. 2 is a block diagram of a radio access network cell outage compensation system;

fig. 3 is a logic diagram of a method for radio access network cell outage compensation in accordance with an embodiment of the present invention;

FIG. 4 is a logic diagram of a method for compensating for interruption in a wireless access network cell according to an embodiment of the present invention, in which a particle swarm optimization algorithm is used to obtain an optimization scheme;

fig. 5 is a schematic diagram of simulation of cell outage compensation in a radio access network according to an embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Fig. 1 shows a method for compensating for interruption in a radio access network cell according to an embodiment of the present invention, which includes the steps of:

s1 collecting and monitoring network information data, judging whether network interruption occurs in the cell according to the network information data, wherein the network information data comprises the receiving power and quality of the mobile user, the service load of the cell and the service type of the user;

s2, if the network of the cell is interrupted, judging whether the interrupted cell needs to be interrupted for compensation;

s3, when the interruption cell needs interruption compensation, optimizing the area coverage rate and coverage overlap aiming at the terminal cell, and obtaining an optimization scheme by utilizing a particle swarm optimization algorithm;

s4, implementing the optimization scheme, and collecting and monitoring network information data after the optimization is completed.

In step S2, it is determined whether the cell with the interruption needs to perform interruption compensation according to the coverage index of the network. Preferably, the wireless access network is an LTE network in an urban environment, and the coverage index satisfies:

the user equipment measures the receiving power value of the main cell to be more than-105 dBm;

the user equipment measures the reception quality value of the primary cell to be greater than-13.8 dB.

The signal to interference and noise ratio of the reference signal received by the user equipment supports the lowest modulation and coding scheme.

Preferably, the method for optimizing area coverage and coverage overlap for the terminal cell in step S3 includes the steps of:

s311, calculating reference signal coverage areas of neighbor cells of the terminal cell respectively by taking the reference signal as a reference, wherein the reference signal coverage areas of the neighbor cells are as follows:

$S\left(p_{\mathrm{RS}}^i\right)=\mathrm{\&pi;}\&CenterDot;{\left(g^{-1}\left({\mathrm{PL}}_{\max }^i\right)\right)}^2$

wherein,

is the reference signal coverage area of the neighbor cell,

for the propagation model of the neighbour cell,

the maximum allowable path loss of the neighbor cell is represented by i belonging to n, and n is the number of the neighbor cells;

s312 obtains a coverage rate of the reference signal in the whole area by using the coverage area of the reference signal in the neighbor cell, where the coverage rate of the reference signal in the whole area is:

$f_{\mathrm{cov}}=100\&CenterDot;\frac{S\left(p_{\mathrm{RS}}^1\right)\&cup;S\left(p_{\mathrm{RS}}^2\right)\&cup;\&CenterDot;\&CenterDot;\&CenterDot;\&cup;S\left(p_{\mathrm{RS}}^n\right)}{S_{t\arg \mathrm{et}}}$

wherein f is_covFor the coverage of the whole area reference signal, S_targetTarget coverage areas for n neighbor cells;

s313, obtaining a coverage overlapping rate of the reference signal of the whole area by using the reference signal coverage area of the neighbor cell, where the whole area includes the reference signal coverage areas of the outage cell and the neighbor cell, and the coverage overlapping rate of the reference signal of the whole area is:

$f_{\mathrm{overlap}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\underset{j,k\&Element;n,j,k\&NotEqual;i}{\overset{n}{\mathrm{\&Sigma;}}}S\left(p_{\mathrm{RS}}^i\right)\&cap;S\left(p_{\mathrm{RS}}^j\right)\&cap;S\left(p_{\mathrm{RS}}^k\right)}{S_{t\arg \mathrm{et}}}$

wherein f is_overlapThe coverage overlap ratio of the reference signal is the whole area.

S314 simultaneously optimizing the coverage rate and the coverage overlap, wherein the optimization function is:

$f_{\mathrm{tot}}=f_{\mathrm{cov}}+k\left(f_{\mathrm{cov}}\right)\&CenterDot;\frac{1}{1+f_{\mathrm{overlap}}}$

wherein, $k\left(f_{\mathrm{cov}}\right)\text{=}\left\{\begin{array}{cc}0,& f_{\mathrm{cov}}<90\\ 100\&CenterDot;{\left(\frac{f_{\mathrm{cov}}-90}{5}\right)}^2,& 90\&le;f_{\mathrm{cov}}<95\\ 100,& \mathrm{else}\end{array}\right.,$ f_totis the optimization function.

According to the coverage rate and the change of the coverage overlapping rate, f_totWill be in the value range of [0,200 ]]In-between, it can be seen that both an increase in coverage and a decrease in coverage overlap can cause f_totIncrease of (i) i.e. f_totThe larger the solution is. The value of k varies with the coverage, and when the coverage is less than 90%, optimizing the coverage becomes the main target, so the importance degree of coverage overlapping is low, and 0 is taken at the moment, so that the coverage can be changedTo improve the coverage rate quickly; when the coverage rate is between 90% and 95%, the k value is gradually increased along with the increase of the coverage rate, which means that the coverage overlapping importance degree is increased along with the increase of the coverage rate, and the coverage overlapping rate is gradually optimized; when the coverage is greater than 95%, k always takes a maximum value. The formula is used for solving, two factors of coverage and communication quality are guaranteed, the weight factor k is used for balancing two optimization targets, and the process of optimizing the two targets simultaneously is achieved.

Preferably, the method for obtaining the optimization scheme by using the particle swarm optimization algorithm in step S3 includes the steps of:

s321 sets maximum iteration times, each neighbor cell sets a position vector and a velocity vector, and the position vector is X_i=(x_i1,x_i2,…,x_iD) The velocity vector is V_i=(v_i1,v_i2,…,v_iD) D is a vector dimension, and the iteration times, the position vector set by each neighbor cell and the velocity vector are initialized;

s322, substituting the position vector and the velocity vector into the optimization function for calculation, and storing an optimal solution in an iterative process by using an optimal solution set;

s323, adding 1 to the iteration times, and updating the position vector and the velocity vector

$v_{\mathrm{id}}^{t+1}=\mathrm{\&omega;}\&CenterDot;v_{\mathrm{id}}^t+c_1{r}_1(p_{\mathrm{id}}^t-x_{\mathrm{id}}^t)+c_2{r}_2(p_{\mathrm{gd}}^t-x_{\mathrm{id}}^t)$

$x_{\mathrm{id}}^{t+1}=x_{\mathrm{id}}^t+v_{\mathrm{id}}^{t+1}$

Where t is the number of iterations, c₁、c₂As an acceleration factor, r₁、r₂Is [0,1 ]]D is the dimension in D dimension, and omega is the inertia weight factor;

s324, if the current iteration times is less than the maximum iteration times, repeating the steps S322-S324, otherwise, outputting a current optimal solution set, wherein the current optimal solution set is the optimization scheme.

The optimization scheme obtained by adopting the particle swarm optimization algorithm has the advantages of high precision, fast convergence and the like, and can rapidly solve a series of problems caused by interruption.

Fig. 2 shows a system for compensating for interruption in a radio access network cell according to an embodiment of the present invention, where the system includes:

the information monitoring module is used for collecting and monitoring network information data and storing the network information data in the information storage module;

the information analysis module is used for analyzing the network information data stored in the information storage module, judging whether network interruption occurs in a cell, judging whether the interrupted cell needs to be subjected to interruption compensation if the network of the cell is interrupted, and sending a compensation request to the compensation planning module if the terminal cell needs to be compensated;

the compensation planning module is used for optimizing the coverage rate and the coverage overlapping of the interrupt cell after receiving the compensation request, obtaining an optimization scheme by utilizing a particle swarm optimization algorithm, storing the optimization scheme into the information storage module and sending an execution request to the scheme execution module;

a scheme execution module, configured to read the optimization scheme of the information storage module after receiving the execution request, and perform interruption compensation on the interruption cell according to the optimization scheme;

and the information storage module is used for storing the network information data and the optimization scheme.

Preferably, the network information data includes a reception power, a reception quality of the mobile subscriber, a traffic load of the cell, and a service type of the subscriber.

Preferably, the compensation planning module sets an optimization function for optimizing the coverage area and the coverage overlap of the outage cell, where the optimization function is:

$f_{\mathrm{tot}}=f_{\mathrm{cov}}+k\left(f_{\mathrm{cov}}\right)\&CenterDot;\frac{1}{1+f_{\mathrm{overlap}}}$

wherein, $k\left(f_{\mathrm{cov}}\right)\text{=}\left\{\begin{array}{cc}0,& f_{\mathrm{cov}}<90\\ 100\&CenterDot;{\left(\frac{f_{\mathrm{cov}}-90}{5}\right)}^2,& 90\&le;f_{\mathrm{cov}}<95\\ 100,& \mathrm{else}\end{array}\right.,$ f_totfor said optimization function, f_covFor the coverage of the whole area reference signal, f_overlapThe coverage overlap ratio of the reference signal for the whole area, which includes the reference signal coverage areas of the outage cell and the neighbor cells.

Preferably, the compensation planning module sets a position vector and a velocity vector for each cell by using a particle swarm optimization algorithm, brings the position vector and the velocity vector into the optimization function to obtain an optimized value, updates the position vector and the velocity vector, and performs optimization iteration to obtain an optimal solution set, where the optimal solution set is the optimization scheme.

Specifically, a logic diagram of the method for compensating for cell outage in a radio access network according to an embodiment of the present invention is shown in fig. 3,

in the detection stage, an information monitoring module collects and monitors network information data, an information analysis module analyzes the network information data and judges whether the cell is interrupted, if the cell is not interrupted, the information monitoring module continues to collect and monitor the network information data, and if the cell is interrupted, the information analysis module enters the analysis stage;

in the analysis stage, an information analysis module collects relevant information, such as network coverage indexes of the cell, and judges whether the cell needs to be interrupted for compensation according to the relevant information, coverage index target reference values given by different networks are different, and a downlink coverage index target reference value of the cell needs to meet the requirements of urban environments in the LTE network: the Reference Signal Received Power (RSRP) value of a main cell in the measurement report data of the user equipment is larger than-105 dBm, the Reference Signal Received Quality (RSRQ) value of the main cell in the measurement report data of the user equipment is larger than-13.8 dB, the signal to interference and noise ratio (SINR) value of the reference signal received by the user equipment is enough to support the lowest Modulation Coding Scheme (MCS), if the cell does not need to interrupt compensation, the system generates an alarm and informs an administrator, and if the cell needs to interrupt compensation, the planning stage is entered;

in the planning stage, a planning module optimizes the area coverage rate and the coverage overlap of the interruption cells, obtains an optimization scheme by using a particle swarm optimization algorithm and enters an execution stage;

and in the execution stage, the scheme execution module adjusts the transmitting power of the reference signal according to the formed compensation scheme, evaluates the compensation result of the compensated network according to various coverage indexes, generates an alarm and informs an administrator.

In the planning stage, in the LTE system, the reference signal is mainly used for channel estimation, and can be used as a reference symbol for downlink measurement, synchronization and data demodulation of users in a cell. In the whole working bandwidth, all antennas broadcast and transmit the RS by adopting constant power, and other signals, such as SCH, PBCH, PCFICH, PDCCH, PDSCH and PHICH, are set by taking RS power as reference. Increasing the power (P) of the RS_RS) The coverage radius can be effectively increased. Based on the above reasons, the optimization target of the present patent is the reference signal transmission power of the neighboring base station, and after the optimization target is determined by using mathematical modeling, a compensation scheme is quickly generated and executed by using a particle swarm optimization algorithm, which is described in detail below.

Discontinuing the cell as eNB₀N neighboring cells around, denoted as N = { eNB₁,eNB₂,…,eNB_nThe corresponding reference signal transmitting power value is P = { P = }¹ _RS,p² _RS,…,pⁿ _RSRepresents it. When eNB₀An interruption occurs and the parameters of the surrounding n neighbor cells need to be adjusted. S (p)ⁱ _RS) Is a reaction of with pⁱ _RSThe coverage area of the ith base station concerned.

Ith cell area S (p)ⁱ _RS) The calculating method of (2): the RSRP is a key parameter for evaluating downlink coverage, and the RSRP of cell edge users is too low to ensure an edge coverage quality target. Let γ be the minimum value of RSRP required by cell edge users to ensure coverage, then the maximum allowed path loss PL of the cellⁱ _maxComprises the following steps:

${{\mathrm{PL}}^i}_{\max }=p_{\mathrm{RS}}^i-\mathrm{\&gamma;}---\left(1\right)$

once the maximum path loss allowed is determined, the maximum coverage radius R of the cell_iCan be calculated by the following equation [11]：

R_i=g^-1((PLⁱ _max-sh_margin)|f,h_BS,h_MS)(2)

In the above formula, sh _ margin is shadow fading, f is system frequency, h_BSIs eNB antenna height, h_MSFor the UE antenna height, the function g (-) is a propagation model selected according to the environment, such as HATA model, Okumura model, etc. Before "|" is meant a variable that changes over a continuous time interval, followed by a discrete value that is fixed in value. Obtaining the maximum coverage radius R of the cell_iThen, the coverage area S (p) can be obtained by the formulas (1) and (2)ⁱ _RS) And pⁱ _RSThe mapping relationship of (1):

$S\left(p_{\mathrm{RS}}^i\right)=\mathrm{\&pi;}\&CenterDot;{\left(g^{-1}\left({\mathrm{PL}}_{\max }^i\right)\right)}^2---\left(3\right)$

one of the important goals of compensation is to ensure coverage of the entire area, minimizing the occurrence of coverage holes, S_targetFor the target coverage areas of n neighbor cells, the coverage of the entire area is defined as follows:

$f_{\mathrm{cov}}=100\&CenterDot;\frac{S\left(p_{\mathrm{RS}}^1\right)\&cup;S\left(p_{\mathrm{RS}}^2\right)\&cup;\&CenterDot;\&CenterDot;\&CenterDot;\&cup;S\left(p_{\mathrm{RS}}^n\right)}{S_{t\arg \mathrm{et}}}---\left(4\right)$

the first optimization objective is to maximize area coverage, expressed as:

Max(f_cov)(5)

increase P_RSThe coverage rate can be effectively improved, but the problems of coverage overlapping, pilot pollution and the like can be brought. When a certain area is served by three or more than three eNBs at the same time, the area is the coverage overlapping area. To simplify the calculation, the present invention considers at most triple overlap. Coverage overlap ratio is defined as follows:

$f_{\mathrm{overlap}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\underset{j,k\&Element;n,j,k\&NotEqual;i}{\overset{n}{\mathrm{\&Sigma;}}}S\left(p_{\mathrm{RS}}^i\right)\&cap;S\left(p_{\mathrm{RS}}^j\right)\&cap;S\left(p_{\mathrm{RS}}^k\right)}{S_{t\arg \mathrm{et}}}---\left(6\right)$

to reduce the occurrence of coverage anomalies for this area, a second optimization objective is to minimize the occurrence of coverage overlap, expressed as:

Min(f_overlap)(7)

according to the above, the core problem of the algorithm is how to optimize two targets simultaneously. To solve this problem, an optimization function is defined that combines an optimization objective (5) with an optimization objective (7)

$f_{\mathrm{tot}}=f_{\mathrm{cov}}+k\left(f_{\mathrm{cov}}\right)\&CenterDot;\frac{1}{1+f_{\mathrm{overlap}}}---\left(8\right)$

Wherein

$k\left(f_{\mathrm{cov}}\right)\text{=}\left\{\begin{array}{cc}0,& f_{\mathrm{cov}}<90\\ 100\&CenterDot;{\left(\frac{f_{\mathrm{cov}}-90}{5}\right)}^2,& 90\&le;f_{\mathrm{cov}}<95\\ 100,& \mathrm{else}\end{array}\right.---\left(9\right)$

According to the coverage rate and the change of the coverage overlapping rate, f_totWill be in the value range of [0,200 ]]In-between, it can be seen that both an increase in coverage and a decrease in coverage overlap can cause f_totIncrease of (i) i.e. f_totThe larger the solution is. The value of k changes along with the change of the coverage rate, when the coverage rate is less than 90%, the optimized coverage rate becomes a main target, so the importance degree of coverage overlapping is very low, and 0 is taken at the moment, so the coverage rate can be quickly improved; when the coverage rate is between 90% and 95%, the k value is gradually increased along with the increase of the coverage rate, which means that the coverage overlapping importance degree is increased along with the increase of the coverage rate, and the coverage overlapping rate is gradually optimized; when coveringWhen the rate is more than 95%, k always takes the maximum value. The formula is used for solving, two factors of coverage and communication quality are guaranteed, the weight factor k is used for balancing two optimization targets, and the process of optimizing the two targets simultaneously is achieved.

The compensation aims at rapidly solving a series of problems caused by interruption, and because the particle swarm optimization algorithm has the advantages of high precision, quick convergence and the like, a specific compensation scheme is obtained by utilizing the particle swarm optimization algorithm. In the algorithm, each particle i contains a position vector X in D dimension_i=(x_i1,x_i2,…,x_iD) Represents P_RSValue of (d), and a velocity vector V_i=(v_i1,v_i2,…,v_iD) And represents the step size of each adjustment. When the particle i searches the solution space, the searched optimal experience position P is saved_i=(p_i1,p_i2,…,p_iD). At the beginning of each iteration, the particles experience a position P optimally according to their own inertia and experience and population_g=(p_g1,p_g2,…,p_gD) To adjust its own velocity vector and to adjust its own position. In each cycle of the algorithm, each particle updates the velocity and position as follows.

$v_{\mathrm{id}}^{t+1}=\mathrm{\&omega;}\&CenterDot;v_{\mathrm{id}}^t+c_1{r}_1(p_{\mathrm{id}}^t-x_{\mathrm{id}}^t)+c_2{r}_2(p_{\mathrm{gd}}^t-x_{\mathrm{id}}^t)---\left(10\right)$

$x_{\mathrm{id}}^{t+1}=x_{\mathrm{id}}^t+v_{\mathrm{id}}^{t+1}---\left(11\right)$

Wherein, c₁、c₂Is an acceleration factor r₁、r₂Is [0,1 ]]Where D is the dimension of D, and omega is the inertial weight factor.

The wireless access network cell interruption compensation method of the embodiment of the invention utilizes a particle swarm optimization algorithm to obtain an optimization scheme as shown in figure 4;

the compensation planning module initializes. Setting the number of loop iterations T_maxLet the cycle counter t =0, set the number of particles, the initial position and the speed; calculating an adaptive value f according to the current position by using the formulas (8) and (9)_totAnd is combined with P_iBy comparison, if X_i>P_iThen P is updated_i=X_i(ii) a For each particle i, the individual velocities are updated according to equation (10)V_iUpdating the individual position X according to equation (11)_iThe loop counter T = T +1 and then the maximum number of iterations T_maxIn comparison, if t<T_maxAnd (5) iteration is carried out, otherwise, an optimal solution set is output, and an optimal compensation scheme is obtained.

The wireless access network cell interruption compensation system of the embodiment of the invention comprises an information monitoring module, an information analysis module, a compensation planning module, a scheme execution module and an information storage module, wherein the information monitoring module, the information analysis module, the compensation planning module, the scheme execution module and the information storage module are 5 functional modules. The specific functions of each module are as follows:

the information monitoring module: and the system is responsible for autonomously monitoring and acquiring information of the bottom network element and storing related data in the information storage module. The monitored and collected network information comprises RSRP and RSRQ of mobile users, the service load of eNodeB, the service type of the users and the like, and the data required for monitoring and collecting of the information analysis module are obtained.

An information analysis module: and judging whether the conditions for cell interruption are met or not by analyzing the network element information in the information storage module. And when the interruption is judged to have occurred, sending a trigger request to the compensation planning module.

And a compensation planning module: and after receiving the compensation request, generating a compensation scheme by autonomously analyzing the data in the information storage module, storing the scheme in the information storage module, and then requesting the scheme execution module to execute the compensation scheme.

A scheme execution module: after receiving the strategy execution request, firstly storing the state information of the current network into an information storage module, then reading related data from the information storage module, autonomously adjusting related parameters of the corresponding eNodeB, continuously acquiring network element information after the scheme execution is finished, and judging whether a compensation result meets the coverage requirement.

An information storage module: and the system is connected with other four modules and used as a data providing center for storing relevant information such as dynamic network monitoring information, network state data, cell interruption compensation schemes and the like. And the information is input and output in a standardized way to ensure the efficient and accurate operation of the functions of each module.

In the simulation test, the simulation environment is the urban environment in the TD-LTE network for simulation, the simulation range is 4.5km multiplied by 4.5km, 7 eNodeBs are distributed in the whole area, and the distance is different from 300m to 500 m. 200 user equipments are randomly distributed in the area. The simulation compensates for the outage cell by adjusting the PRS to increase the coverage of the neighbor cell. The other main parameters are shown in table 1. Fig. 5 visually shows the distribution of the base stations and the users, and the results obtained after the compensation algorithm is executed.

TABLE 1 simulation parameters

In fig. 5, the dotted circle area is a schematic view of the coverage area of the base station under normal conditions, and from a certain time point, the eNB located in the central area₀The interruption results in the generation of coverage holes. And after adjustment is carried out according to the obtained final adjustment scheme, the solid line circumference is a coverage schematic diagram after the compensation algorithm is executed. By P to neighbor base stations_RSFinally, the coverage rate of the area can reach 98.5%, the coverage overlapping rate is 1.6%, and in the existing network, effective coverage can be realized when the coverage rate reaches 98%, so that the simulation result reaches the target reference value of the coverage rate.

The method and the system for compensating the interruption of the wireless access network cell utilize the network of the cell around the terminal cell, optimize the coverage rate and coverage overlapping of the interruption cell by adopting the particle swarm optimization algorithm, realize the automatic interruption compensation of the interruption cell, improve the speed of the interruption compensation, better reduce the performance loss of users in the interruption cell, furthest reduce the intervention of human to the network operation and effectively improve the network operation efficiency.

The above embodiments are only for illustrating the invention and are not to be construed as limiting the invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention, therefore, all equivalent technical solutions also belong to the scope of the invention, and the scope of the invention is defined by the claims.

Claims (10)

1. A method for compensating for radio access network cell outage, the method comprising the steps of:

s1, collecting and monitoring network information data, and judging whether network interruption occurs in the cell according to the network information data;

s2, if the network of the cell is interrupted, judging whether the interrupted cell needs to be interrupted for compensation;

s3, when the interruption cell needs interruption compensation, optimizing the area coverage rate and coverage overlap aiming at the terminal cell, and obtaining an optimization scheme by utilizing a particle swarm optimization algorithm;

s4, implementing the optimization scheme, and collecting and monitoring network information data after the optimization is completed.

2. The radio access network cell outage compensation method of claim 1, wherein the network information data includes received power of mobile users, received quality, traffic load of a cell and service type of a user.

3. The method for compensating for interruption of radio access network cell according to claim 1, wherein in step S2, it is determined whether the interrupted cell needs to perform interruption compensation according to the coverage index of the network.

4. The method of claim 3, wherein the radio access network is an LTE network in an urban environment, and the coverage indicator satisfies:

the user equipment measures the receiving power value of the main cell to be more than-105 dBm;

the user equipment measures the reception quality value of the primary cell to be greater than-13.8 dB.

The signal to interference and noise ratio of the reference signal received by the user equipment supports the lowest modulation and coding scheme.

5. The radio access network cell outage compensation method of claim 1, wherein the method for area coverage and coverage overlap optimization for the terminal cell in step S3 comprises the steps of:

s311, calculating reference signal coverage areas of neighbor cells of the terminal cell respectively by taking the reference signal as a reference, wherein the reference signal coverage areas of the neighbor cells are as follows:

$S\left(p_{\mathrm{RS}}^i\right)=\mathrm{\&pi;}\&CenterDot;{\left(g^{-1}\left({\mathrm{PL}}_{\max }^i\right)\right)}^2$

wherein,

is the reference signal coverage area of the neighbor cell,

for the propagation model of the neighbour cell,

the maximum allowable path loss of the neighbor cell is represented by i belonging to n, and n is the number of the neighbor cells;

s312 obtains a coverage rate of the reference signal in the whole area by using the coverage area of the reference signal in the neighbor cell, where the coverage rate of the reference signal in the whole area is:

$f_{\mathrm{cov}}=100\&CenterDot;\frac{S\left(p_{\mathrm{RS}}^1\right)\&cup;S\left(p_{\mathrm{RS}}^2\right)\&cup;\&CenterDot;\&CenterDot;\&CenterDot;\&cup;S\left(p_{\mathrm{RS}}^n\right)}{S_{t\arg \mathrm{et}}}$

wherein f is_covFor the coverage of the whole area reference signal, S_targetTarget coverage areas for n neighbor cells;

s313, obtaining a coverage overlapping rate of the reference signal of the whole area by using the reference signal coverage area of the neighbor cell, where the whole area includes the reference signal coverage areas of the outage cell and the neighbor cell, and the coverage overlapping rate of the reference signal of the whole area is:

$f_{\mathrm{overlap}}=\frac{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\underset{j,k\&Element;n,j,k\&NotEqual;i}{\overset{n}{\mathrm{\&Sigma;}}}S\left(p_{\mathrm{RS}}^i\right)\&cap;S\left(p_{\mathrm{RS}}^j\right)\&cap;S\left(p_{\mathrm{RS}}^k\right)}{S_{t\arg \mathrm{et}}}$

wherein f is_overlapThe coverage overlap ratio of the reference signal is the whole area.

S314 simultaneously optimizing the coverage rate and the coverage overlap, wherein the optimization function is:

$f_{\mathrm{tot}}=f_{\mathrm{cov}}+k\left(f_{\mathrm{cov}}\right)\&CenterDot;\frac{1}{1+f_{\mathrm{overlap}}}$

wherein, $k\left(f_{\mathrm{cov}}\right)\text{=}\left\{\begin{array}{cc}0,& f_{\mathrm{cov}}<90\\ 100\&CenterDot;{\left(\frac{f_{\mathrm{cov}}-90}{5}\right)}^2,& 90\&le;f_{\mathrm{cov}}<95\\ 100,& \mathrm{else}\end{array}\right.,$ f_totis the optimization function.

6. The method for compensating for cell outage in a wireless access network according to claim 5, wherein the step S3 of using a particle swarm optimization algorithm to obtain an optimization scheme comprises the steps of:

s321 sets maximum iteration times, each neighbor cell sets a position vector and a velocity vector, and the position vector is X_i=(x_i1,x_i2,…,x_iD) The velocity vector is V_i=(v_i1,v_i2,…,v_iD) D is a vector dimension, and the iteration times, the position vector set by each neighbor cell and the velocity vector are initialized;

s322, substituting the position vector and the velocity vector into the optimization function for calculation, and storing an optimal solution in an iterative process by using an optimal solution set;

s323, adding 1 to the iteration times, and updating the position vector and the velocity vector

$v_{\mathrm{id}}^{t+1}=\mathrm{\&omega;}\&CenterDot;v_{\mathrm{id}}^t+c_1{r}_1(p_{\mathrm{id}}^t-x_{\mathrm{id}}^t)+c_2{r}_2(p_{\mathrm{gd}}^t-x_{\mathrm{id}}^t)$

$x_{\mathrm{id}}^{t+1}=x_{\mathrm{id}}^t+v_{\mathrm{id}}^{t+1}$

Where t is the number of iterations, c₁、c₂As an acceleration factor, r₁、r₂Is [0,1 ]]D is the dimension in D dimension, and omega is the inertia weight factor;

s324, if the current iteration times is less than the maximum iteration times, repeating the steps S322-S324, otherwise, outputting a current optimal solution set, wherein the current optimal solution set is the optimization scheme.

7. A system for compensating for radio access network cell outage, the system comprising:

the information monitoring module is used for collecting and monitoring network information data and storing the network information data in the information storage module;

the information analysis module is used for analyzing the network information data stored in the information storage module, judging whether network interruption occurs in a cell, judging whether the interrupted cell needs to be subjected to interruption compensation if the network of the cell is interrupted, and sending a compensation request to the compensation planning module if the terminal cell needs to be compensated;

the compensation planning module is used for optimizing the coverage rate and the coverage overlapping of the interrupt cell after receiving the compensation request, obtaining an optimization scheme by utilizing a particle swarm optimization algorithm, storing the optimization scheme into the information storage module and sending an execution request to the scheme execution module;

a scheme execution module, configured to read the optimization scheme of the information storage module after receiving the execution request, and perform interruption compensation on the interruption cell according to the optimization scheme;

and the information storage module is used for storing the network information data and the optimization scheme.

8. The radio access network cell outage compensation system of claim 7, wherein the network information data includes received power of mobile users, received quality, traffic load of a cell and service type of a user.

9. The radio access network cell outage compensation system of claim 7, wherein the compensation planning module sets an optimization function for area coverage and coverage overlap optimization of the outage cell, the optimization function being:

$f_{\mathrm{tot}}=f_{\mathrm{cov}}+k\left(f_{\mathrm{cov}}\right)\&CenterDot;\frac{1}{1+f_{\mathrm{overlap}}}$

wherein, $k\left(f_{\mathrm{cov}}\right)\text{=}\left\{\begin{array}{cc}0,& f_{\mathrm{cov}}<90\\ 100\&CenterDot;{\left(\frac{f_{\mathrm{cov}}-90}{5}\right)}^2,& 90\&le;f_{\mathrm{cov}}<95\\ 100,& \mathrm{else}\end{array}\right.,$ f_totfor said optimization function, f_covFor the coverage of the whole area reference signal, f_overlapThe coverage overlap ratio of the reference signal for the whole area, which includes the reference signal coverage areas of the outage cell and the neighbor cells.

10. The system of claim 9, wherein the compensation planning module sets a position vector and a velocity vector for each cell by using a particle swarm optimization algorithm, brings the position vector and the velocity vector into the optimization function to obtain an optimized value, updates the position vector and the velocity vector, and performs optimization iteration to obtain an optimal solution set, wherein the optimal solution set is the optimization scheme.

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