CN103052145A - Method for multi-mode mobile terminal to select sector with high service quality - Google Patents

Abstract

The invention relates to a method for a multi-mode mobile terminal to select a sector with high service quality, and the method is characterized by consisting the following steps that (100) the multi-mode terminal checks all sectors in a local position, and calculates the number N of the sectors; (200) particle swarm optimization is transferred to select at least one sector as a sector selection scheme; and (300) the multi-mode terminal are accessed in the sector according to the sector selection scheme based on the particle swarm optimization. The method for the multi-mode mobile terminal to select the sector with high service quality is operated on a multi-mode mobile terminal side, aims to improve the service quality of the multi-mode mobile terminal, selects an appropriate sector combination for each multi-mode mobile terminal, and has the advantages of convenience in operation, clear steps, higher stability, low algorithm complexity and the like.

Description

Method for selecting high service quality sector by multi-mode mobile terminal

Technical Field

The invention relates to the technical field of sectorization cellular wireless network communication, in particular to a method for selecting a high-service-quality sector by a multi-mode mobile terminal.

Background

Currently, cellular mobile communication technology, a mature mobile communication technology, has been deployed in more than 200 countries around the world to provide communication services for more than 30 billion users. With the increase of the number of operators and the scarcity of spectrum resources, competition among operators is more and more intense, and the service quality of a cellular network becomes a decisive factor for selecting the operator and the network mode by a user.

Conventional cellular mobile communication refers to omni-directional cellular, i.e., a base station transmits a wireless signal to a full range of 360 degrees. Since the radio spectrum resources are very limited, operators must continually shrink the cell size to improve system performance in order to continually increase the capacity of users in an area. However, the continuous reduction in cell size greatly increases the cost of deployment and frequency interference of neighboring cells, and conventional cellular spectrum reuse has not been able to fully meet mobile communication requirements.

For the above reasons, in order to further increase the system capacity without increasing the total number of cells, a sectorization technique is generally adopted, in which a mobile communication cell is divided into several sectors and each sector is provided with a separate transceiving antenna. I.e. each sector corresponds to an independent cell. The sector division modes commonly used at present are 120 degrees and 60 degrees.

The cellular network divided by the sectors can effectively enhance the signal energy and improve the network service quality of users. Because the energy of the radio frequency is concentrated in a certain angle, compared with the previous 360 degrees, the signal strength of the user is larger, and the service quality is higher. Meanwhile, because the signals of a certain frequency are only concentrated in a certain angle, the same-frequency signals can be reused in a closer area, and the same-frequency interference is avoided while the spectrum utilization efficiency is enhanced.

With the continuous progress of the technology, the multimode terminal can access 2 or more sector signals at the same time, for example, some multimode terminals can use the sector signals of GSM for voice communication while using TD-SCDMA sector signals for 3G network downloading. The simultaneous access of a plurality of sectors not only enhances the flexibility of the access of the multimode terminal, but also improves the service quality of the user and can effectively improve the satisfaction degree of the user.

However, since the multimode terminal can simultaneously select multiple sectors for access, sector selection becomes a very difficult problem to solve, which is a nondeterministic problem of polynomial complexity, NP for short. At present, no scheme for effectively searching the optimal solution exists for the problems, and the optimal solution is difficult to obtain in polynomial time. For example, if the multimode terminal has 10 sectors with signal strength for selective access, the sector selection scheme has 2¹⁰1024 species. The multimode terminal has limited computing power and cannot verify the feasibility and quality of service of all 1024 schemes in a limited time.

Meanwhile, when the number of mobile multimode terminals and sectors in a cell is large and the mobile terminal has sectors available for selection in multiple network modes, the selection and allocation of sectors by the mobile multimode terminal become very complicated. Since the shape of each sector is not already a conventional hexagonal cell, and the frequency allocation of the sectors is different from that of the conventional cell, the conventional hexagonal cell selection strategy is no longer applicable in the 120 ° and 60 ° sector selection.

Through searching the current IEEE technical literature, it is found that the current multimode terminal sector selection often uses an evolutionary algorithm, and representative literatures thereof are as follows: a genetic algorithm-based sector selection scheme is described in the dynami section of microcells for cellular traffic in CDMA, genetic algorithm for Aproach (journal of IEEEtransactions on Vehicular Technology, Volume:51, Issue: 1). In this scheme, the sectors are selected and finalized by genetic algorithm iteration. However, the genetic algorithm is easily trapped in premature convergence and evolutionary stagnation, the convergence speed is slow, and the obtained service quality value of the distribution scheme is not high. Meanwhile, when the number of sectors and the number of active terminals are large, the calculation speed of the genetic algorithm is slow, and the real-time requirement of the system cannot be met.

The particle swarm algorithm is a new evolutionary algorithm developed in recent years. The particle swarm algorithm starts from a random solution, finds an optimal solution through iteration, and evaluates the quality of the solution through fitness. It is simpler than the genetic algorithm rules, it has no "crossover" and "mutation" operations of the genetic algorithm, it finds the global optimum by following the currently searched optimum value. The particle swarm algorithm has the advantages of easiness in implementation, high precision, high convergence and the like, draws attention of academic circles, and shows superiority in many practical problems. Since the sector selection problem of the multimode terminal belongs to the nondeterministic problem of polynomial complexity which is good for solving by the particle swarm algorithm, how to apply the particle swarm algorithm to sector allocation has become one of the key issues concerned by related researchers.

Disclosure of Invention

The invention provides a method for selecting a high-service-quality sector by a multi-mode mobile terminal, which is used for solving the problems that the convergence speed of a sector allocation algorithm in the prior art is low and the service quality value of an obtained sector selection scheme is not high.

The invention provides a method for selecting a high-service-quality sector by a multi-mode mobile terminal, which comprises the following steps:

step S100, the multi-mode mobile terminal traverses all sectors at the position, and counts the number N of the sectors, wherein N is a natural number;

step S200, calling a particle swarm algorithm to select at least one sector as a sector selection scheme;

step S300, the multi-mode mobile terminal accesses the sector according to the sector selection scheme selected by the particle swarm algorithm;

wherein, step S200 includes the following steps:

step S210, carrying out binary coding on the positions x of the particles of the particle swarm algorithm according to the number N of sectors, and coding the positions x into a binary sequence with the length of N;

step S220, initializing particle swarm algorithm parameters, setting the number of particles as D, the maximum iteration number as M, and M and D as natural numbers, and endowing each particle with an initial random position x₀And velocity v₀；

Step S230, calculating the initial position x of the particle₀A quality of service value of;

step S240, updating the speed of each particle according to a calculation formula, namely the speed of the particle in the k +1 th iteration

The calculation formula is as follows:

$v_{\mathrm{id}}^{k+1}=v_{\mathrm{id}}^k+2\×\mathrm{rand}\left(1\right)\×(p_{\mathrm{id}}^k-x_{\mathrm{id}}^k)+2\×\mathrm{rand}\left(1\right)\×(p_{\mathrm{gd}}^k-x_{\mathrm{gd}}^k)$

in the formula, k is iteration times, k is a natural number,

representing the historical optimal position of the current particle,

represents the optimal position of the global history,

is the position of the current particle,

representing the position of the optimal particle in the current particle swarm, rand (1) representing a random number between 0 and 1 randomly generated by a computer,

representing the velocity of the particle at the k-th iteration,

represents the velocity of the particle at the k +1 th iteration;

step S250, according to the speed of the particles in the (k + 1) th iteration described in the step S240

Updating the position of each particle according to a calculation formula, namely the position of the particle at the k +1 th iteration

The calculation formula is as follows:

wherein,

is the position of the particle at the (k + 1) th iteration,

represents the velocity of the particle at the k +1 th iteration;

step S260, according to the position of the particle in the k +1 th iterationCalculating the position of each particle in the population

A quality of service value of;

step S270, judging whether the iteration number k is larger than the maximum iteration number M or not, and outputting the iteration number k if the iteration number k reaches the maximum iteration number M

As a sector selection scheme; otherwise, return to step S240.

Further, in the method for selecting a sector with high quality of service by a multi-mode mobile terminal according to the present invention, in step S220, the number of particles D =50 and the maximum number of iterations M =100 are set.

Further, in the method for selecting a high quality of service sector by a multi-mode mobile terminal according to the present invention, in step S210, at least 10 selectable sectors are set, where N is a natural number and is greater than or equal to 10.

Further, in the method for selecting a sector with high service quality by a multi-mode mobile terminal according to the present invention, in step S200, a particle swarm algorithm is run on the multi-mode mobile terminal.

Further, in the method for selecting a high quality of service sector by a multi-mode mobile terminal according to the present invention, in step S200, a sector in a sectorized cell is selected by using a particle swarm algorithm.

The method for selecting the high-service-quality sector by the multimode mobile terminal has the advantages that:

in the process of selecting the sector selection scheme by the multimode mobile terminal, the selected particle swarm algorithm is clear in process, simple to implement, less in required parameters and high in algorithm convergence speed, and the service quality of the multimode mobile terminal in the sector is effectively improved; meanwhile, compared with the method for selecting the sector of the multimode mobile terminal by utilizing the genetic algorithm in the prior art, the method can obtain a better solution in a shorter time and cannot fall into a calculation stagnation state.

The simulation result of the software simulation experiment shows that the method for selecting the high-service-quality sector by the multimode mobile terminal provided by the invention is improved by about 10% compared with the service quality value obtained by the genetic algorithm in the prior art.

In conclusion, the method of the invention can improve the service quality value of the multi-mode mobile terminal, and has good popularization prospect. The method is completely operated at the side of the multimode mobile terminal, aims at improving the service quality of the multimode mobile terminal, selects a proper sector combination for each multimode mobile terminal, and has the advantages of convenient operation, clear steps, strong stability, low algorithm complexity and the like.

Drawings

FIG. 1 is a schematic overall flow chart of the method of example 2 of the present invention;

FIG. 2 is a detailed flowchart of step S200 of the method of embodiment 2 of the present invention;

FIG. 3 is a graph comparing the terminal quality of service value of the method of example 1 of the present invention with that of a genetic algorithm of the prior art;

FIG. 4 is a graph comparing the terminal quality of service value of the method of example 2 of the present invention with that of the genetic algorithm of the prior art.

Detailed Description

For a better understanding of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

The embodiment of the invention provides a method for selecting a high-service-quality sector by a multi-mode mobile terminal.

Example 1:

fig. 1 is a schematic flow chart of the overall process of the method of embodiment 1 of the present invention, as shown in fig. 1,

the method for selecting the high-service-quality sector by the multi-mode mobile terminal provided by the embodiment 1 of the invention comprises the following steps:

step S100, the multi-mode mobile terminal traverses all sectors at the position and counts the number N of the sectors;

step S200, calling a particle swarm algorithm to select at least one sector as a sector selection scheme;

step S300, the multi-mode mobile terminal accesses the sector according to the sector selection scheme selected by the particle swarm algorithm;

fig. 2 is a detailed flowchart of step S200 of the method according to embodiment 2 of the present invention, as shown in fig. 2, wherein step S200 includes the following steps:

step S210, carrying out binary coding on the positions x of the particles of the particle swarm algorithm according to the number N of sectors, and coding the positions x into a binary sequence with the length of N;

for example, if there are 10 sectors to choose from, 0000000001 represents the multimode terminal accessing the first sector, and 0000000011 represents the multimode terminal accessing the first and second sectors simultaneously. By analogy, 1111111111 represents that the multimode terminal accesses ten sectors at the same time.

Step S220, initializing particle swarm algorithm parameters, setting the number of particles as D and the maximum iteration number as M, and endowing each particle with an initial random position x₀And velocity v₀；

Setting the number of particles D =50 and the maximum iteration number M as 100;

step S230, calculating the initial position x of the particle₀A quality of service value of;

the method specifically comprises the following steps:

step S231, setting a network jitter upper limit value;

step S232, according to the initial position x of the particle₀Obtaining the selected sector;

step S233, obtaining the network jitter values of the selected sectors, adding the network jitter values of all the selected sectors, comparing the added network jitter values with the network jitter upper limit value, and if the added network jitter values are greater than the network jitter upper limit value, comparing the initial position x with the network jitter upper limit value₀Is recorded as 0; if the added network jitter valueIf the value is less than or equal to the network jitter upper limit value, the process goes to step S234;

step S234, after summing the download rates of all the selected sectors and carrying out quotient normalization with the upper limit of the download rate of the multi-mode mobile terminal, the obtained value is the initial position x₀Quality of service value of (2).

In this embodiment 1, parameters are selected according to the current specific service condition of the multi-mode mobile terminal, and the particle position x is calculated by using a summation normalization method₀Corresponding quality of service values. In embodiment 1, the multimode mobile terminal is performing a video call service, the higher the download rate is, the clearer the video is, and the higher the call quality is, the download rate is selected as a parameter to calculate the quality of service value. The service quality value is obtained by summing the download rates of all the sectors and carrying out quotient normalization on the sum and the upper limit of the download rate of the multimode terminal, but the service quality value is 0, the service quality value is limited by the acceptable upper limit of the network jitter, the video call is very blocked after the acceptable upper limit of the network jitter is exceeded, the service cannot be normally carried out.

For example, the upper limit of the download rate of the multimode terminal is 10Mbps (megabits per second), and the upper limit of the acceptable network jitter is 10ms (milliseconds).

The bandwidth and cost of sector 1 are 1.5Mbps and 5ms respectively.

The bandwidth and cost of sector 2 are 1Mbps and 9ms respectively.

The bandwidth and cost of sector 3 are 1.5Mbps and 3ms respectively.

When the particle position x₀At 0000000011, the multimode terminal accesses both the first and second sectors.

Then the network jitter for both access sector 1 and sector 2 is 5ms +9ms =14ms, exceeding the acceptable upper network jitter limit of 10ms, i.e. the particle position 0000000011 has a quality of service value of 0.

When the particle position x₀0000000101, the multimode terminal accesses the first and third simultaneouslyIf the network jitter of the simultaneous access sector 1 and sector 3 is 5ms +3ms =8ms, the network jitter does not exceed the acceptable upper limit of the network jitter by 10ms, and therefore the service quality value corresponding to the particle position 0000000101 is not 0.

The sum of the bandwidths of the access sector 1 and the access sector 3 is 1.5Mbps +1.5Mbps, and the quotient of the sum and the upper limit 10Mbps of the download rate of the multimode terminal is as follows:

(1.5 Mbps +1.5 Mbps) ÷ 10Mbps = 0.3. I.e. particle position 0000000101 corresponds to a quality of service value of 0.3.

Step S240, updating the speed of each particle according to a calculation formula, namely the speed of the particle in the k +1 th iterationThe calculation formula is as follows:

$v_{\mathrm{id}}^{k+1}=v_{\mathrm{id}}^k+2\×\mathrm{rand}\left(1\right)\×(p_{\mathrm{id}}^k-x_{\mathrm{id}}^k)+2\×\mathrm{rand}\left(1\right)\×(p_{\mathrm{gd}}^k-x_{\mathrm{gd}}^k)$

in the formula, k is the number of iterations,

representing the historical optimal position of the current particle,

represents the optimal position of the global history,

is the position of the current particle,

representing the position of the optimal particle in the current particle swarm, rand (1) representing a random number between 0 and 1 randomly generated by a computer,

representing the velocity of the particle at the k-th iteration,represents the velocity of the particle at the k +1 th iteration;

step S250, according to the speed of the particles in the (k + 1) th iteration described in the step S240

Updating the position of each particle according to a calculation formula, namely the position of the particle at the k +1 th iteration

The calculation formula is as follows:

wherein,

is the position of the particle at the (k + 1) th iteration,

represents the velocity of the particle at the k +1 th iteration;

step S260, according to the position of the particle in the k +1 th iteration

Calculating the position of each particle in the population

A quality of service value of;

the method specifically comprises the following steps:

step S261, setting a network jitter upper limit value;

step S262, according to the position of the particle in the k +1 th iteration

Obtaining the selected sector;

step S263, obtaining the network jitter values of the selected sectors, adding the network jitter values of all the selected sectors, comparing the added network jitter values with the network jitter upper limit value, and if the added network jitter values are greater than the network jitter upper limit value, determining the positions of the particles in the (k + 1) th iteration

Is recorded as 0; if the added network jitter value is less than or equal to the network jitter upper limit value, go to step S264;

step S264, after summing the download rates of all the selected sectors and carrying out quotient normalization with the upper limit of the download rate of the multi-mode mobile terminal, the obtained value is the bit of the particle during the k +1 iterationDevice for placing

Quality of service value of (2).

In this embodiment 1, parameters are selected according to the current specific service condition of the multi-mode mobile terminal, and the positions of particles are calculated by a summation normalization methodCorresponding quality of service values. In embodiment 1, the multimode mobile terminal is performing a video call service, the higher the download rate is, the clearer the video is, and the higher the call quality is, the download rate is selected as a parameter to calculate the quality of service value. The service quality value is obtained by summing the download rates of all the sectors and carrying out quotient normalization on the sum and the upper limit of the download rate of the multimode terminal, but the service quality value is 0, the service quality value is limited by the acceptable upper limit of the network jitter, the video call is very blocked after the acceptable upper limit of the network jitter is exceeded, the service cannot be normally carried out.

For example, the upper limit of the download rate of the multimode terminal is 10Mbps (megabits per second), and the upper limit of the acceptable network jitter is 10ms (milliseconds).

The bandwidth and cost of sector 1 are 1.5Mbps and 5ms respectively.

The bandwidth and cost of sector 2 are 1Mbps and 9ms respectively.

The bandwidth and cost of sector 3 are 1.5Mbps and 3ms respectively.

When the particle positionAt 0000000011, the multimode terminal accesses both the first and second sectors.

Then the network jitter for both access sector 1 and sector 2 is 5ms +9ms =14ms, exceeding the acceptable upper network jitter limit of 10ms, i.e. the particle position 0000000011 has a quality of service value of 0.

When the particle isPosition of

0000000101, the multimode terminal accesses the first and third sectors simultaneously, and the network jitter of the simultaneously accessed sector 1 and sector 3 is 5ms +3ms =8ms, which does not exceed the acceptable upper limit of network jitter by 10ms, so the service quality value corresponding to the particle position 0000000101 is not 0.

The sum of the bandwidths of the access sector 1 and the access sector 3 is 1.5Mbps +1.5Mbps, and the quotient of the sum and the upper limit 10Mbps of the download rate of the multimode terminal is as follows:

(1.5 Mbps +1.5 Mbps) ÷ 10Mbps = 0.3. I.e. particle position 0000000101 corresponds to a quality of service value of 0.3.

Step S270, judging whether the iteration number k is larger than the maximum iteration number M or not, and outputting the iteration number k if the iteration number k reaches the maximum iteration number M

As a sector selection scheme; otherwise, return to step S240.

The parameter configuration and simulation results of the computer simulation experiment of example 1 will be given in detail below.

The inventive embodiment has 10 sectors in total. The multi-mode mobile terminal can arbitrarily select one or several from 10 sectors of the location. The upper limit of the download rate of the multimode terminal is 10Mbps (megabits per second) and the upper limit of the acceptable network jitter is 10ms (milliseconds). The bandwidth of each sector is randomly generated between 0 and 2Mbps, and the network jitter is randomly generated between 0 and 10 ms. In the particle swarm optimization, the number of particles D is 50, the maximum iteration number is 100, the minimum speed of the particles is 0, and the maximum speed is 6. The number of individuals in the genetic algorithm population used for comparison is 50, the maximum iteration number is 100, the cross probability is 0.7, and the variation probability is 0.05.

FIG. 3 is a graph comparing the terminal quality of service value of the method of example 1 of the present invention with that of the genetic algorithm of the prior art. As shown in fig. 3, the upper solid line in fig. 3 is a service quality value curve simulated by the method for selecting a high service quality sector by the multi-mode mobile terminal according to embodiment 1 of the present invention, and the lower dotted line is a service quality value curve obtained by a genetic algorithm in the prior art. It can be seen from the simulation curve that, in the process of 100 iterations, the value of the service quality value of the multi-mode mobile terminal obtained by the method in embodiment 1 of the present invention is 0.04 to 0.05 higher than the value of the service quality value of the multi-mode mobile terminal obtained by the genetic algorithm, that is, the performance is improved by 8% to 10%, which indicates that the result of the sector and network mode allocation obtained by the method of the present invention can significantly improve the communication service quality of the terminal. Meanwhile, as can be seen from the figure, the performance of the method is more stable than that of the genetic algorithm, the method gradually becomes flat and converges after 50 iterations, and the genetic algorithm does not reach horizontal convergence in the whole 100 iteration processes, so that the method is not beneficial to the adoption of an actual system.

Example 2:

the method for selecting the high-service-quality sector by the multi-mode mobile terminal provided by the embodiment 2 of the invention comprises the following steps:

step S100, the multi-mode mobile terminal traverses all sectors at the position and counts the number N of the sectors;

step S200, calling a particle swarm algorithm to select at least one sector as a sector selection scheme;

step S300, the multi-mode mobile terminal accesses the sector according to the sector selection scheme selected by the particle swarm algorithm;

step S200 includes the steps of:

step S210, carrying out binary coding on the positions x of the particles of the particle swarm algorithm according to the number N of sectors, and coding the positions x into a binary sequence with the length of N;

in embodiment 2, there are 10 sectors available for selection, and 0000000001 represents that the multimode terminal accesses the first sector, and 0000000011 represents that the multimode terminal accesses the first and second sectors simultaneously. By analogy, 1111111111 represents that the multimode terminal accesses ten sectors at the same time.

Step S220, initializing particle swarm algorithm parameters, setting the number of particles as D and the maximum iteration number as M, and endowing each particle with an initial random position x₀And velocity v₀；

Initializing particle swarm algorithm parameters, setting the number of particles D =10 and the maximum number of iterations M =100, and assigning an initial random position x to each particle₀And velocity v₀，x₀A random binary sequence of 0 or 1 is generated by the computer, with a length of 10. v. of₀Is a random rational number between 0 and 6 and is generated by a computer.

Step S230, calculating the initial position x of the particle₀A quality of service value of;

the method specifically comprises the following steps:

step S231, setting an upper limit value of network cost;

step S232, according to the initial position x of the particle₀Obtaining the selected sector;

step S233, obtaining the network cost value of the selected sector, adding the network cost values of all the selected sectors, comparing with the upper limit value of the network cost, if the added network cost value is larger than the upper limit value of the network cost, then comparing the initial position x₀Is recorded as 0; if the added network cost value is less than or equal to the upper limit value of the network cost, the step S234 is carried out;

step S234, after summing the download rates of all the selected sectors and carrying out quotient normalization with the upper limit of the download rate of the multi-mode mobile terminal, the obtained value is the initial position x₀Quality of service value of (2).

In this embodiment 2, a parameter is selected according to the current specific service condition of the multi-mode mobile terminal, and a summation normalization method is used to calculate the particle position x₀Corresponding quality of service values. Embodiment 2, the multi-mode terminal is performing the file downloading service and selects the downloading speedThe rate is used as a parameter to calculate the quality of service value. The service quality value is obtained by summing the download rates of all the sectors and then carrying out quotient normalization on the sum and the upper limit of the download rate of the multimode terminal, but the service quality value is limited by the acceptable upper limit of the cost and is 0 after the service quality value exceeds the acceptable upper limit of the cost.

For example, the upper limit of the download rate of the multi-mode mobile terminal is 10Mbps, and the upper limit of the acceptable cost is 0.06 yuan/min.

The bandwidth and cost of sector 1 are 2Mbps and 0.04 yuan/min respectively.

The bandwidth and cost of sector 2 are 1Mbps and 0.01 yuan/min respectively.

The bandwidth and cost of sector 3 are 1.5Mbps and 0.05 yuan/min respectively.

When the particle position x₀At 0000000011, the multimode mobile terminal accesses both the first and second sectors.

The cost of accessing sector 1 and sector 2 simultaneously is 0.04 yuan/min +0.01 yuan/min =0.05 yuan/min, and the acceptable upper limit of the cost is not exceeded by 0.06 yuan/min, without setting the quality of service value to 0.

The bandwidth of the access sector 1 and the bandwidth of the access sector 2 are 2Mbps +1Mbps, and after the quotient normalization with the upper limit of the download rate of the multimode terminal is as follows: (2 Mbps +1 Mbps) ÷ 10Mbps = 0.3. I.e. particle position 0000000011 corresponds to a quality of service value of 0.3.

When the particle position x₀0000000101, the multimode terminal accesses the first and third sectors simultaneously, and the cost of accessing sector 1 and sector 3 simultaneously is 0.04 yuan/min +0.05 yuan/min =0.09 yuan/min, which exceeds the acceptable upper limit of the cost by 0.06 yuan/min, so the service quality value corresponding to the particle position 0000000101 is 0.

Step S240, updating the speed of each particle according to a calculation formula, namely the speed of the particle in the k +1 th iteration

The calculation formula is as follows:

$v_{\mathrm{id}}^{k+1}=v_{\mathrm{id}}^k+2\×\mathrm{rand}\left(1\right)\×(p_{\mathrm{id}}^k-x_{\mathrm{id}}^k)+2\×\mathrm{rand}\left(1\right)\×(p_{\mathrm{gd}}^k-x_{\mathrm{gd}}^k)$

in the formula, k is the number of iterations,

representing the historical optimal position of the current particle,represents the optimal position of the global history,

is the position of the current particle,representing the position of the optimal particle in the current particle swarm, rand (1) representing a random number between 0 and 1 randomly generated by a computer,

representing the velocity of the particle at the k-th iteration,represents the velocity of the particle at the k +1 th iteration;

the velocity of the particle at 1 st iteration and at k th iterationIs an initial random velocity v₀Current position of particle

And the position of the optimum particle in the precursor particle group

Is an initial random position x₀Historical optimal location of current particle

Is an initial random position x₀. I.e. at the 1 st iteration,

thereafter, calculation is performed according to the calculation formula of step S240.

The subtraction here is binary subtraction, specifically according to the following rule: if the corresponding bits are the same, it is 0, and if the corresponding positions are different, it is 1.

For example, 0000000111-0000000101= 0000000010.

Step S250, according to the k +1 times described in step S240Velocity of particles in iterationsUpdating the position of each particle according to a calculation formula, namely the position of the particle at the k +1 th iteration

The calculation formula is as follows:

wherein,

is the position of the particle at the (k + 1) th iteration,

represents the velocity of the particle at the k +1 th iteration;

step S260, according to the position of the particle in the k +1 th iteration

Calculating the position of each particle in the population

A quality of service value of;

the method specifically comprises the following steps:

step S261, setting an upper limit value of the network charge;

step S262, according to the position of the particle in the k +1 th iteration

Obtaining the selected sector;

step S263, obtaining the network cost value of the selected sector, adding the network cost values of all the selected sectors, comparing the added network cost values with the upper limit value of the network cost, and if the added network cost value is larger than the upper limit value of the network cost, determining the position of the particle in the k +1 th iteration

Is recorded as 0; if the added network cost value is less than or equal to the upper limit value of the network cost, the step S264 is executed;

step S264, after summing the download rates of all the selected sectors and carrying out quotient normalization with the upper limit of the download rate of the multi-mode mobile terminal, the obtained value is the position of the particle in the k +1 th iteration

Quality of service value of (2).

In this embodiment 2, parameters are selected according to the current specific service condition of the multimode terminal, and the positions of particles are calculated by a summation normalization method

Corresponding quality of service values. In embodiment 2, the multimode terminal is performing a file download service, and selects a download rate as a parameter to calculate a quality of service value. The service quality value is obtained by summing the download rates of all the sectors and then carrying out quotient normalization on the sum and the upper limit of the download rate of the multimode terminal, but the service quality value is limited by the acceptable upper limit of the cost and is 0 after the service quality value exceeds the acceptable upper limit of the cost.

For example, the upper limit of the download rate of the multimode terminal is 10Mbps, and the upper limit of the acceptable cost is 0.06 yuan/min.

The bandwidth and cost of sector 1 are 2Mbps and 0.04 yuan/min respectively.

The bandwidth and cost of sector 2 are 1Mbps and 0.01 yuan/min respectively.

The bandwidth and cost of sector 3 are 1.5Mbps and 0.05 yuan/min respectively.

When the particle position

At 0000000011, the multimode terminal accesses both the first and second sectors.

The cost of accessing sector 1 and sector 2 simultaneously is 0.04 yuan/min +0.01 yuan/min =0.05 yuan/min, and the acceptable upper limit of the cost is not exceeded by 0.06 yuan/min, without setting the quality of service value to 0.

The bandwidth of the access sector 1 and the bandwidth of the access sector 2 are 2Mbps +1Mbps, and after the quotient normalization with the upper limit of the download rate of the multimode terminal is as follows: (2 Mbps +1 Mbps) ÷ 10Mbps = 0.3. I.e. particle position 0000000011 corresponds to a quality of service value of 0.3.

When the particle position

0000000101, the multimode terminal accesses the first and third sectors simultaneously, and the cost of accessing sector 1 and sector 3 simultaneously is 0.04 yuan/min +0.05 yuan/min =0.09 yuan/min, which exceeds the acceptable upper limit of the cost by 0.06 yuan/min, so the service quality value corresponding to the particle position 0000000101 is 0.

Step S270, judging whether the iteration number k is larger than the maximum iteration number M or not, and outputting the iteration number k if the iteration number k reaches the maximum iteration number M

As a sector selection scheme; otherwise, return to step S240.

The parameter configuration and simulation results of the computer simulation experiment of example 2 will be given in detail below.

In embodiment 2 of the present invention, there are 10 sectors. The multimode terminal can arbitrarily select one or several from 10 sectors in the location. The upper limit of the download rate of the multimode terminal is 10Mbps, and the upper limit of the acceptable cost is 0.06 yuan/min. The bandwidth of each sector is randomly generated between 0 and 2Mbps, and the cost of each sector is randomly generated between 0 and 0.06 yuan/minute. In the particle swarm optimization, the number of particles D is 50, the maximum iteration number is 100, the minimum speed of the particles is 0, and the maximum speed is 6. The number of individuals in the genetic algorithm population used for comparison is 50, the maximum iteration number is 100, the cross probability is 0.7, and the variation probability is 0.05.

FIG. 4 is a graph comparing the terminal quality of service value of the method of example 2 of the present invention with that of the genetic algorithm of the prior art. As shown in fig. 4, the upper solid line in fig. 4 is a service quality value curve simulated by the method for selecting a high service quality sector by the multi-mode mobile terminal according to embodiment 2 of the present invention, and the lower dotted line is a service quality value curve obtained by a genetic algorithm in the prior art. It can be seen from the simulation curve that after 100 times of iterative operations, the value of the service quality value of the multi-mode mobile terminal obtained by the method of embodiment 2 of the present invention is 0.05 higher than the value of the service quality of the multi-mode mobile terminal obtained by the genetic algorithm, that is, the performance is improved by 10%, which indicates that the sector and network mode allocation result obtained by the method of the present invention can significantly improve the communication service quality of the terminal. Meanwhile, as can be seen from the figure, the performance of the method is more stable than that of the genetic algorithm, the method gradually becomes flat and converges after 50 iterations, and the genetic algorithm is always in a remarkable fluctuation process in the whole 100 iteration processes, so that the obtained service quality value has stronger randomness and is not beneficial to the adoption of an actual system.

The foregoing is only a preferred embodiment of the present invention, and naturally there are many other embodiments of the present invention, and those skilled in the art can make various corresponding changes and modifications according to the present invention without departing from the spirit and the essence of the present invention, and these corresponding changes and modifications should fall within the scope of the appended claims.

Claims (5)

1. A method for selecting a high-service quality sector by a multi-mode mobile terminal is characterized by comprising the following steps:

step S100, the multi-mode mobile terminal traverses all sectors at the position, and counts the number N of the sectors, wherein N is a natural number;

step S200, calling a particle swarm algorithm to select at least one sector as a sector selection scheme;

step S300, the multi-mode mobile terminal accesses the sector according to the sector selection scheme selected by the particle swarm algorithm;

wherein, step S200 includes the following steps:

step S210, carrying out binary coding on the positions x of the particles of the particle swarm algorithm according to the number N of sectors, and coding the positions x into a binary sequence with the length of N;

step S220, initializing particle swarm algorithm parameters, setting the number of particles as D, the maximum iteration number as M, and M and D as natural numbers, and endowing each particle with an initial random position x₀And velocity v₀；

Step S230, calculating the initial position x of the particle₀A quality of service value of;

step S240, updating the speed of each particle according to a calculation formula, namely the speed of the particle in the k +1 th iteration

The calculation formula is as follows:

$v_{\mathrm{id}}^{k+1}=v_{\mathrm{id}}^k+2\×\mathrm{rand}\left(1\right)\×(p_{\mathrm{id}}^k-x_{\mathrm{id}}^k)+2\×\mathrm{rand}\left(1\right)\×(p_{\mathrm{gd}}^k-x_{\mathrm{gd}}^k)$

in the formula, k is iteration times, k is a natural number,

representing the historical optimal position of the current particle,

represents the optimal position of the global history,

is the position of the current particle,

representing the position of the optimal particle in the current particle swarm, rand (1) representing a random number between 0 and 1 randomly generated by a computer,

representing the velocity of the particle at the k-th iteration,

represents the velocity of the particle at the k +1 th iteration;

step S250, according to the speed of the particles in the (k + 1) th iteration described in the step S240

Updating the position of each particle according to a calculation formula, namely the position of the particle at the k +1 th iteration

The calculation formula is as follows:

wherein,

is the position of the particle at the (k + 1) th iteration,

represents the velocity of the particle at the k +1 th iteration;

step S260, according to the position of the particle in the k +1 th iteration

Calculating the position of each particle in the population

A quality of service value of;

step S270, judging whether the iteration number k is larger than the maximum iteration number M or not, and outputting the iteration number k if the iteration number k reaches the maximum iteration number M

As a sector selection scheme; otherwise, return to step S240.

2. The method of claim 1, wherein in step S220, the number of particles D =50 and the maximum number of iterations M =100 are set.

3. The method of claim 2, wherein in step S210, at least 10 optional sectors are set, the number N of sectors is greater than or equal to 10, and N is a natural number.

4. The method for selecting high service quality sector by the multi-mode mobile terminal according to any one of claims 1 to 3, wherein in the step S200, the particle swarm algorithm is operated on the multi-mode mobile terminal.

5. The method of claim 4, wherein the step S200 is performed by using a particle swarm algorithm to select the sector in the sectorized cell.

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