CN104320772A - Trust degree and physical distance based D2D (Device to Device) communication node clustering method and device - Google Patents

Abstract

The invention provides a trust degree and physical distance based D2D (Device to Device) communication node clustering method and device. The trust degree and physical distance based D2D communication node clustering method comprises obtaining the physical distance between a first user and a second user; obtaining the trust degree between the first user and the second user; calculating a selective probability value between the first user and the second user according to the physical distance between the first user and the second user and the trust degree between the first user and the second user so as to obtain a selective probability value between every two users in a community; performing D2D communication node clustering on the users in the community according to the selective probability value between every two users in the community. According to the trust degree and physical distance based D2D communication node clustering method and device, the trust degree and physical distance based clustering method in the D2D communication field is given and accordingly the improvement of the system throughput and efficiency is effectively implemented.

Description

Based on D2D communication node clustering method and the device of degree of belief and physical distance

Technical field

The present invention relates to communication technical field, particularly relate to a kind of D2D communication node clustering method based on degree of belief and physical distance and device.

Background technology

D2D (Device to Device) communication is widely used in hot spot region service, usually forms D2D bunch of Serial Communication of going forward side by side between adjacent user.Due to the difference of frequency spectrum share mode, D2D communication has different mode of operations.Overlay frequency spectrum share mode is the special frequency spectrum resource of D2D communication reservation, and the frequency spectrum resource of D2D user multiplexing phone user under ensureing not disturb the prerequisite of cellular subscriber communications in Underlay mode.Because the equipment of D2D communication is mostly handheld device, the degree of belief between these equipment holder also plays very crucial effect to D2D communication.Therefore, in D2D between subscriber equipment communication, need to consider the impact that degree of belief between user is indispensable on this.With the correlative study of D2D bunch, mostly it is considered that the discussion of other problems under D2D bunch of scene, as the associating precoding strategy etc. of power division, D2D and co-channel cellular transmission, only consider cluster between the close equipment of physical distance merely and carry out the technical scheme of D2D communication, but do not consider whether these users have a mind to cooperate or directly suppose all users all cooperative simply, and this does not conform to actual conditions.In the research of existing D2D bunch, do not have degree of belief between D2D equipment holder and the concrete research report of degree of belief being used to indicate degree of belief, rarely have article to analyze the gain of D2D communication node cluster more specificly yet.

Summary of the invention

The invention provides a kind of D2D communication node clustering method based on degree of belief and physical distance and device, be applicable to Overlay and Underlay frequency spectrum share mode, to solve the technical problem in prior art, the research of D2D communication node clustering method all not being related to degree of belief between D2D equipment holder.

For solving the problems of the technologies described above, the invention provides a kind of D2D communication node clustering method based on degree of belief and physical distance, comprising:

Obtain the physical distance between first user and the second user;

Obtain the degree of belief between first user and the second user;

Calculate the select probability value between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user, and obtain the select probability value in community between every two users thus;

D2D communication node cluster is carried out according to all users in the select probability Zhi Dui community between two users every in described community.

Further, the described select probability value calculated between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user comprises:

Based on distributing the Chinese restaurant's process dividing client according to dining table, calculate the select probability value between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user.

Further, the physical distance between described acquisition first user and the second user comprises: obtain the physical distance between i-th user and a jth user, and be expressed as d (i, j);

Degree of belief between described acquisition first user and the second user comprises: obtain the degree of belief between i-th user and a jth user, and be expressed as p (i, j), wherein p (i, j) ∈ [0,1].

Further, the described select probability value calculated between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user also comprises:

The trust distance between i-th user and a jth user is calculated: s (i, j)=-log according to the degree of belief p (i, j) between described i-th user and a jth user ₂p (i, j), obtains the matrix S that the trust distance between every two users is formed;

A jth user is selected to be expressed as the probability of its D2D communication parter i-th user:

$P(c_i=j|S,D,\mathrm{\α})=\left\{\begin{array}{cc}\frac{f_2\left(s(i,j)\right)}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},\mathrm{if}& i\≠j,\\ \frac{\mathrm{\α}}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},\mathrm{if}& i=j,\end{array}\right.$

Wherein, c _irepresent i-th user-selected D2D communication parter, the matrix that D is formed for the physical distance between every two users, α is the scalar parameter of described Chinese restaurant process, function f ₂(s (i, j)) is defined as:

$f_2\left(s(i,j)\right)=\left\{\begin{array}{cc}\frac{1}{s(i,j)},\mathrm{if}& d(i,j)\≤d_{\max }\\ 0,\mathrm{if}& d(i,j)>d_{\max }\end{array}\right.$

D _maxfor the greatest physical distance between D2D communication node.

Further, the degree of belief between described first user and the second user is for representing the probability of file and/or resource-sharing between two users: when described degree of belief is larger, and between two users, the probability of file and/or resource-sharing is larger; Otherwise then between two users, the probability of file and/or resource-sharing is less;

Described method is applicable to D2D Overlay frequency spectrum share mode in cellular network and Underlay frequency spectrum share mode simultaneously.

On the other hand, the present invention also provides a kind of D2D communication node cluster device based on degree of belief and physical distance, comprising:

Physical distance acquiring unit, for obtaining the physical distance between first user and the second user;

Degree of belief acquiring unit, for obtaining the degree of belief between first user and the second user;

Select probability value computing unit, degree of belief between the described first user obtained for the physical distance between the described first user that obtains according to described physical distance acquiring unit and the second user and described degree of belief acquiring unit and the second user, calculate the select probability value between described first user and described second user, and obtain the select probability value in community between every two users thus;

Cluster unit, for carrying out D2D communication node cluster according to all users in the select probability Zhi Dui community between two users every in described community.

Further, described select probability value computing unit is used for:

Based on distributing the Chinese restaurant's process dividing client according to dining table, calculate the select probability value between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user.

Further, described physical distance acquiring unit is used for: obtain the physical distance between i-th user and a jth user, and be expressed as d (i, j);

Described degree of belief acquiring unit is used for: obtain the degree of belief between i-th user and a jth user, and be expressed as p (i, j), wherein p (i, j) ∈ [0,1].

Further, described select probability value computing unit is used for:

The trust distance between i-th user and a jth user is calculated: s (i, j)=-log according to the degree of belief p (i, j) between described i-th user and a jth user ₂p (i, j), obtains the matrix S that the trust distance between every two users is formed;

A jth user is selected to be expressed as the probability of its D2D communication parter i-th user:

$P(c_i=j|S,D,\mathrm{\α})=\left\{\begin{array}{cc}\frac{f_2\left(s(i,j)\right)}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},\mathrm{if}& i\≠j,\\ \frac{\mathrm{\α}}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},\mathrm{if}& i=j,\end{array}\right.$

Wherein, c _irepresent i-th user-selected D2D communication parter, the matrix that D is formed for the physical distance between every two users, α is the scalar parameter of described Chinese restaurant process, function f ₂(s (i, j)) is defined as:

$f_2\left(s(i,j)\right)=\left\{\begin{array}{cc}\frac{1}{s(i,j)},\mathrm{if}& d(i,j)\≤d_{\max }\\ 0,\mathrm{if}& d(i,j)>d_{\max }\end{array}\right.$

D _maxfor the greatest physical distance between D2D communication node.

Further, described degree of belief acquiring unit for the degree of belief between the first user that obtains and the second user for representing the probability of file and/or resource-sharing between two users: when described degree of belief is larger, between two users, the probability of file and/or resource-sharing is larger; Otherwise then between two users, the probability of file and/or resource-sharing is less;

Described device is applicable to D2D Overlay frequency spectrum share mode in cellular network and Underlay frequency spectrum share mode simultaneously.

Visible, in the D2D communication node clustering method based on degree of belief and physical distance provided by the invention and device, consider that degree of belief and physical distance are on the impact of D2D communication node cluster, combine and consider to trust Distance geometry physical distance factor to improve the performance of D2D bunch of communication; The trust distance between two users is defined, in order to assess its impact on cluster based on degree of belief; Random process-Chinese restaurant's the process dividing client is distributed according to dining table based on a kind of, the present invention carries out division cluster to user, and utilize the thought of Chinese restaurant's process that distance is relevant, define some specific users and select other users as the probability of its D2D communication parter; Between the number of users upper limit of each D2D bunch and D2D communication node greatest physical distance double constraints under, obtain final D2D communication node cluster result.As a comparison, The present invention gives the cluster scheme of physically based deformation distance, and share the performance of gain to D2D communication node cluster brought analyze by assessment file resource.Method and apparatus of the present invention gives the cluster scheme based on degree of belief and physical distance in the D2D communications field, effectively achieves the lifting of throughput of system and efficiency.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is the system schematic of D2D communication in single subdistrict;

Fig. 2 is the embodiment of the present invention based on the basic procedure schematic diagram of the D2D communication node clustering method of degree of belief and physical distance;

Fig. 3 is different d _max, N _maxthe relation of throughput and total number of users under value;

Fig. 4 is different d _max, N _maxthe relation of energy ezpenditure and total number of users under value;

Fig. 5 is different d _max, N _maxthe relation of efficiency and total number of users under value;

Fig. 6 is different q ₁, q ₂, q ₃the relation of throughput and total number of users under value;

Fig. 7 is different q ₁, q ₂, q ₃the relation of energy ezpenditure and total number of users under value;

Fig. 8 is different q ₁, q ₂, q ₃the relation of efficiency and total number of users under value;

Fig. 9 is throughput and d under different total number of users value _maxrelation;

Figure 10 is energy ezpenditure and d under different total number of users value _maxrelation;

Figure 11 is efficiency and d under different total number of users value _maxrelation;

Figure 12 is the embodiment of the present invention based on the basic procedure schematic diagram of the D2D communication node cluster device of degree of belief and physical distance.

Embodiment

For making the object of the embodiment of the present invention, technical scheme and advantage clearly, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

Under the environment of single subdistrict, there is N number of user, this N number of user both can directly and BS (base station, base station) communicated by cellular link, also can form D2D bunch according to own situation, D2D communication can be carried out between the user of D2D bunch to meet self-demand and to reduce communication cost.

This system model schematic diagram as shown in Figure 1.Suppose that channel between base station and user obeys large scale path loss model, the channel between D2D user is independent same distribution flat fading channel, channel gain only with distance dependent.The noise of channel is average is zero, variance is σ ²additive white Gaussian noise (AWGN).

Channel response between definition user x and user y is h _xy, the number of users upper limit of each D2D bunch is N _max, maximum D2D communication distance is d _max, K is the quantity of D2D bunch.Correspondingly, define user's set of i-th D2D bunch, N _ithe number of users of this D2D bunch, P _band P _dthe transmitted power of BS and D2D user respectively.

An advantage of D2D communication node cluster is, the user of same D2D bunch can be communicated shared file resource by D2D, and without the need to obtaining via BS, this can improve throughput, reduce energy consumption.But existing research just hypothesis neighboring user forms D2D bunch, and obviously this does not meet reality.

In practical application scene, the wish degree of different user shared file or resource is different, therefore, also needs the impact of the degree of belief considering D2D user, and it is very important for how dividing user's cluster in order to improve performance.

Certainly, except degree of belief, physical distance restriction is also a key factor of D2D communication.Thus, in order to improve the performance of D2D bunch of communication, consider degree of belief and physical distance factor by combining, first the embodiment of the present invention provides a kind of D2D communication node clustering method based on degree of belief and physical distance, see Fig. 2, comprising:

Step 201: obtain the physical distance between first user and the second user.

Step 202: obtain the degree of belief between first user and the second user.

Step 203: calculate the select probability value between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user, and obtain the select probability value in community between every two users thus.

Step 204: carry out D2D communication node cluster according to all users in the select probability Zhi Dui community between two users every in described community.

Visible, the embodiment of the present invention provide based in the D2D communication node clustering method of degree of belief and physical distance, considered degree of belief with physical distance factor to improve the D2D bunch of performance communicated, effectively achieved the lifting of throughput of system and efficiency.

Wherein, degree of belief represents the trust value between intra-cell users, and in the cell, have higher degree of belief between the user that mutually, information transmission number of times is more, frequency is higher, also corresponding possess larger trust value.

Preferably, can comprise according to the select probability value that the physical distance between described first user and the second user and the degree of belief between described first user and the second user calculate between described first user and described second user: based on distributing the Chinese restaurant's process dividing client (Chinese Restaurant Process according to dining table, CRP), the select probability value between described first user and described second user is calculated according to the physical distance between first user and the second user and the degree of belief between first user and the second user.

The select probability that Chinese restaurant process CRP defines is distributed as: based on the selection situation of n-1 client above, defines a select probability distribution to the n-th client arrived

$P(z_n=k|Z_{-n},\mathrm{\α})=\left\{\begin{array}{cc}\frac{m_k}{n-1+\mathrm{\α}},& \mathrm{if\; k}\≤k_0,\\ \frac{\mathrm{\α}}{n-1+\mathrm{\α}},& \mathrm{if\; k}=k_0+1,\end{array}\right.$

Wherein, k ₀by the dining table quantity that client takies, m _kthe Number of Customers of a kth dining table, Z _-nfor the distribution condition of n-1 arrival user above.

Be different from traditional Chinese restaurant's process, in the embodiment of the present invention, use for reference the thought of the relevant Chinese restaurant's process of distance: the selection of user, not by the impact of other users, only considers the relation between two users.

Preferably, the physical distance obtained between first user and the second user can comprise: obtain the physical distance between i-th user and a jth user, and be expressed as d (i, j).

When only considering the factor of physical distance, also namely adopt D-CRP clustering method, then define i-th user and select user j as the probability of its D2D communication parter to be:

$P(c_i=j|D,\mathrm{\α})=\left\{\begin{array}{cc}\frac{f_1\left(d(i,j)\right)}{{\mathrm{\Σ}}_{j\≠i}{f}_1\left(d(i,j)\right)+\mathrm{\α}},\mathrm{if}& i\≠j,\\ \frac{\mathrm{\α}}{{\mathrm{\Σ}}_{j\≠i}{f}_1\left(d(i,j)\right)+\mathrm{\α}},\mathrm{if}& i=j,\end{array}\right.$

Wherein, c _irepresent i-th user-selected D2D communication parter, the distance matrix of D for forming between any two users, α is the scalar parameter of described Chinese restaurant process, function f ₁(s (i, j)) is defined as:

$f_1\left(d(i,j)\right)=\left\{\begin{array}{cc}\frac{1}{d(i,j)},\mathrm{if}& d(i,j)\≤d_{\max }\\ 0,\mathrm{if}& d(i,j)>d_{\max }\end{array}\right.$

D _maxfor the greatest physical distance between D2D communication node.

In D-CRP clustering method, i-th user according to the select probability value between other all users, Stochastic choice and which user or alone together.

Preferably, the degree of belief obtained between first user and the second user can comprise: obtain the degree of belief between i-th user and a jth user, and be expressed as p (i, j), wherein p (i, j) ∈ [0,1].And carry out cluster according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user by SD-CRP clustering method and specifically can comprise the steps:

The trust distance between i-th user and a jth user is calculated: s (i, j)=-log according to the degree of belief p (i, j) between described i-th user and a jth user ₂p (i, j), obtains the matrix S that the trust distance between every two users is formed, and wherein, trust distance and also can be interpreted as: the radius (the radius of trust) of trust, when trusting distance and increasing, degree of belief reduces;

A jth user is selected to be expressed as the probability of its D2D communication parter i-th user:

$P(c_i=j|S,D,\mathrm{\α})=\left\{\begin{array}{cc}\frac{f_2\left(s(i,j)\right)}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},\mathrm{if}& i\≠j,\\ \frac{\mathrm{\α}}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},\mathrm{if}& i=j,\end{array}\right.$

Wherein, c _irepresent i-th user-selected D2D communication parter, the matrix that D is formed for the physical distance between every two users, α is the scalar parameter of described Chinese restaurant process, function f ₂(s (i, j)) is defined as:

$f_2\left(s(i,j)\right)=\left\{\begin{array}{cc}\frac{1}{s(i,j)},\mathrm{if}& d(i,j)\≤d_{\max }\\ 0,\mathrm{if}& d(i,j)>d_{\max }\end{array}\right.$

D _maxfor the greatest physical distance between D2D communication node.

Preferably, the degree of belief between first user and the second user may be used for the probability of file and/or resource-sharing between expression two users: when described degree of belief is larger, and between two users, the probability of file and/or resource-sharing is larger; Otherwise then between two users, the probability of file and/or resource-sharing is less.

Be different from traditional Chinese restaurant process, D-CRP with SD-CRP clustering method utilizes the thought of Chinese restaurant's process that distance is relevant, and carry out the cluster process of modeling users, this process is non-swappable.

In the SD-CRP clustering method that the embodiment of the present invention proposes, except considering physical distance, we include degree of belief in consideration simultaneously.Between D2D communication node greatest physical distance constraint under, for some users, the SD-CRP method that the embodiment of the present invention proposes can select the user of larger probability shared file resource as partner using greater probability.Therefore, for the scheme that the embodiment of the present invention proposes, more effectively can share their file resource between the user of same D2D bunch, and not need to be obtained by BS, without doubt, this can improve the performance of D2D communication node cluster.

Consider to trust Distance geometry physical distance by combining, the clustering method of the embodiment of the present invention can from the gain effectively improving D2D communication node cluster.

Analyze the D2D communication node cluster performance based on degree of belief and physical distance of the embodiment of the present invention below: when a user obtains file resource from BS, it can carry out sharing of resource with other users in need of this D2D bunch.Therefore, can analyze the performance of D2D communication node cluster under this scene, also namely assessment bunch file resource share brought gain, comprise throughput, energy consumption and efficiency etc.

For the user of same bunch, the degree of belief between two users can be utilized as the probability of their shared file resources.

In i-th D2D bunch, for a kth user, when it obtains a file from BS, this bunch has n user to want the probability being obtained this file by file-sharing to be expressed as:

Wherein, n=0 ..., N _i-1, N _ithe number of users of this D2D bunch, υ _jrepresent the υ of i-th D2D bunch _jindividual user, p _i(κ, υ _j) represent a kth user and υ _jdegree of belief between individual user, p _i(κ, υ ₀)=1.

For a kth user, its speed obtaining file from BS can be obtained by following formulae discovery:

$R_{\mathrm{B\κ}}^i={\log }_2(1+\frac{P_B{\left|h_{\mathrm{B\κ}}^i\right|}^2}{{\mathrm{\σ}}^2})$

Wherein, P _bthe transmitted power of BS, that channel between BS to a kth user is corresponding, σ ²the power of AWGN noise.

In considering i-th D2D bunch, the file resource of a kth user and n user is shared, and it sends file to this n user in a broadcast manner, and we can calculate the throughput brought by the file transfer between BS and a kth user and are:

$R_{\mathrm{B\κ}}^{i0}=R_{\mathrm{B\κ}}^i+\underset{n=1}{\overset{N_i-1}{\mathrm{\Σ}}}{R}_d^i\left(\mathrm{\κ}\right){|}_n$

Wherein, the situation of n=0 is not considered, because now do not have file-sharing, does not also just have the increase of throughput.In addition, n user by with a kth user carry out D2D communicate obtain required file resource time, the average throughput brought is:

Wherein, a kth user and υ _jspeed between individual user is

$R_{\mathrm{\κ}{\mathrm{\υ}}_j}^i={\log }_2(1+\frac{P_D{\left|h_{\mathrm{\κ}{\mathrm{\υ}}_j}^i\right|}^2}{{\mathrm{\σ}}^2})$

For all users of i-th D2D bunch, the throughput brought to the file transfer of these users by BS can be expressed as:

$R_t^i=\underset{\mathrm{\κ}=1}{\overset{N_i}{\mathrm{\Σ}}}{R}_{\mathrm{B\κ}}^{i0}=\underset{\mathrm{\κ}=1}{\overset{N_i}{\mathrm{\Σ}}}(R_{\mathrm{B\κ}}^i+\underset{n=1}{\overset{N_i-1}{\mathrm{\Σ}}}{R}_d^i\left(\mathrm{\κ}\right){|}_n)$

For all users of K D2D bunch, the total throughout brought can be expressed as:

$R_t=\underset{i=1}{\overset{K}{\mathrm{\Σ}}}{R}_t^i$

Suppose that the file obtained from BS has identical length (L ₀), each D2D bunch is assigned with identical bandwidth (W ₀).Thus, for a kth user, obtain transmission time of file from BS and energy ezpenditure can be expressed as successively:

$D_{\mathrm{B\κ}}^i=\frac{L_0}{W_0{R}_{\mathrm{B\κ}}^i}$

$E_{\mathrm{B\κ}}^i=P_B{D}_{\mathrm{B\κ}}^i$

When n the user of i-th D2D bunch want by file resource share obtain this file time, then a kth user transmits average transmission time required for this file and energy ezpenditure can be obtained by following formulae discovery:

$E_{\mathrm{d\κ}}^i=P_D{D}_{\mathrm{d\κ}}^i$

Similarly, the situation of n=0 is not included.Wherein, P _dthe transmitted power of D2D user, be the minimum-rate value in the speed set between n user and a kth user, it can be expressed as:

$R_{\mathrm{\κ}n\min }^i=\underset{j=1,...,n}{\min }\{R_{\mathrm{\κ}{\mathrm{\υ}}_1}^i,...,R_{\mathrm{\κ}{\mathrm{\υ}}_j}^i,...,R_{\mathrm{\κ}{\mathrm{\υ}}_n}^i\}$

When a kth user with this file of broadcast transmission to n user time, the time required for it is weighed with the maximum duration needed for transfer files, also gives by file complete transmission the time that corresponding user needs.

The energy consumption that can calculate the throughput brought by the file transfer of the user of BS to all D2D bunch corresponding is:

$E_t=\underset{i=1}{\overset{K}{\mathrm{\Σ}}}\left(\underset{\mathrm{\κ}=1}{\overset{N_i}{\mathrm{\Σ}}}(E_{\mathrm{B\κ}}^i+E_{\mathrm{d\κ}}^i)\right)$

Although the file resource of D2D bunch is shared can bring higher throughput, the corresponding energy ezpenditure of same generation.Thus, efficiency can be utilized to assess the performance of D2D communication node cluster scheme, and its definition can be expressed as:

$\mathrm{\η}=\frac{R_t}{E_t}$

Without loss of generality, when not utilizing D2D cluster, namely when not cluster, user obtains file from BS, and we calculate the throughput of lower i-th D2D bunch of this situation respectively and all user's total throughouts are:

$R_t^i=\underset{\mathrm{\κ}=1}{\overset{N_i}{\mathrm{\Σ}}}(R_{\mathrm{B\κ}}^i+\underset{n=1}{\overset{N_i-1}{\mathrm{\Σ}}}{R}_B^i\left(\mathrm{\κ}\right){|}_n)$

$R_t=\underset{i=1}{\overset{K}{\mathrm{\Σ}}}{R}_t^i$

Wherein, the average throughput that n the user of i-th D2D bunch brings from the file that BS obtains a kth user is:

And have: υ _jthe speed that individual user obtains file from BS is

$R_{B{\mathrm{\υ}}_j}^i={\log }_2(1+\frac{P_B{\left|h_{B{\mathrm{\υ}}_j}^i\right|}^2}{{\mathrm{\σ}}^2})$

Wherein, bS and υ _jchannel response between individual user.

Same, can calculate not in cluster situation, when n the user of i-th D2D bunch goes for this file, its energy ezpenditure is:

Similarly, the total power consumption of user of all D2D bunch is:

$E_t=\underset{i=1}{\overset{K}{\mathrm{\Σ}}}\left(\underset{\mathrm{\κ}=1}{\overset{N_i}{\mathrm{\Σ}}}(E_{\mathrm{B\κ}}^i+E_{\mathrm{B\κ}0}^i)\right)$

Apparently, the efficiency in not cluster situation can also be obtained:

$\mathrm{\η}=\frac{R_t}{E_t}$

So far, obtain for D2D communication node cluster result very important the embodiment of the present invention, and throughput of system, energy consumption, efficiency etc. weigh target, and validity and the feasibility of D2D communication node clustering method can be assessed according to performance evaluation.

According to above-mentioned each measurement target, indices assessment can be carried out based on the cluster result of the D2D communication node clustering method of degree of belief and physical distance and cluster result of the prior art and compare in the embodiment of the present invention.

The embodiment of the present invention respectively for SD-CRP clustering method, D-CRP clustering method, random clustering method and not clustering method emulate.First simply introduce random clustering method and not clustering method: random clustering method, under being the restriction of greatest physical distance between D2D communication node, user's Stochastic choice user is as D2D communication parter; And not clustering method, also namely each user directly and BS carry out interactive communication.

Under the simulated environment of the present embodiment, user be evenly distributed on central point for (100,0), radius be in the border circular areas of 100m, the position of BS is (300,0).Further, the large scale decline index between BS and phone user is β=3.5, and between D2D user is then β=4.In order to simplify calculating, we only consider the decline based on distance.In addition arrange parameter alpha=0.1 of Chinese restaurant's process, the variance of AWGN is σ ²=-60dBm.The transmitted power of BS and D2D subscriber equipment is respectively: P _b=0.2W, P _d=0.1W.File size is L ₀=1MB, the bandwidth that each D2D bunch distributes is W ₀=1MHz.

In order to for simplicity, can consider that a kind of special scene is to contrast the performance of different schemes: the degree of belief between user is divided into three reliability ratings, this degree of belief corresponding to three reliability ratings is respectively q ₁, q ₂, q ₃also the degree of belief p (i, j) namely between i-th user and a jth user can equal q ₁or equal q ₂or equal q ₃.

First, we analyze greatest physical distance d between different D2D communication node _maxwith the number of users upper limit N of each D2D bunch _maxunder value, total the performance that Different Strategies changes with number of users, now q ₁=0.8, q ₂=0.6, q ₃=0.4.

As can be seen from Figure 3, at d _max, N _maxwhen getting different numerical value, the throughput of SD-CRP clustering method is always greater than the throughput in additive method.When total number of users increases gradually, the corresponding increase all thereupon of the methodical throughput of institute.In addition, d _maxthe impact changed for throughput is greater than N _maxchange the impact brought.When total number of users is less, increase d _maxor reduce N _maxall can improve the throughput of SD-CRP clustering method and D-CRP clustering method, vice versa.

Fig. 4 gives methodical Energy Expenditure Levels, and the energy consumption of clustering method much larger than the energy consumption of other clustering methods, will not which illustrate the advantage of D2D communication node cluster in energy ezpenditure.In addition, compared to D-CRP clustering method and random clustering method, due in the method that adopts in the embodiment of the present invention, D2D bunch can more effectively be carried out file resource and share, thus result in higher energy consumption.In order to the performance of more completely appraisal procedure, in Figure 5, describe methodical efficiency, as can be seen from Figure 5, compared with other all methods, the clustering method of the embodiment of the present invention has larger efficiency.

Then can analyze at different degree of belief q ₁, q ₂, q ₃under value, the performance that distinct methods changes along with total number of users, now maximum D2D communication distance d _maxthe number of users higher limit N of=20m, D2D bunch _max=10.

As shown in Figure 6, at two groups of different q ₁, q ₂, q ₃under value, the throughput of SD-CRP clustering method is all greater than the throughput of additive method.Meanwhile, q ₁, q ₂, q ₃increase for methodical throughput improve and have positive facilitation.

Fig. 7 shows methodical energy ezpenditure, and the energy consumption of clustering method is still not large than the energy consumption of additive method.Similarly, due to bunch file resource share, the clustering method of the embodiment of the present invention has larger energy ezpenditure than other clustering methods.Fig. 8 gives the efficiency under distinct methods, can find out, q ₁, q ₂, q ₃value larger, the efficiency numerical value of SD-CRP clustering method and D-CRP clustering method is larger.The clustering method that this simulation result also demonstrates embodiment of the present invention proposition has better performance than additive method in efficiency.

In addition, also can analyze under different total number of users values, distinct methods is along with maximum D2D communication distance d _maxthe performance of change, now, N _max=10, q ₁=0.8, q ₂=0.6, q ₃=0.4.

From the simulation result curve that Fig. 9 obtains, can find out, when total number of users is fixed, along with d _maxincrease, the throughput of SD-CRP clustering method and D-CRP clustering method first increases rear reduction.For all methods, the increase of total number of users can improve throughput of system.In the method for all contrasts, work as d _maxwhen value is not very large, the SD-CRP clustering method of proposition shows better throughput performance.

Figure 10 describes methodical energy ezpenditure, and similarly, the energy consumption of clustering method is not greater than additive method.In fig. 11, we can see the performance efficiency of all control methods, and simulation result curve shows, works as d _maxwhen value is not too large, compared with additive method, the SD-CRP clustering method that the embodiment of the present invention proposes can realize higher efficiency.

The embodiment of the present invention also provides a kind of D2D communication node cluster device based on degree of belief and physical distance, see Figure 12, comprising:

Physical distance acquiring unit 1201, for obtaining the physical distance between first user and the second user;

Degree of belief acquiring unit 1202, for obtaining the degree of belief between first user and the second user;

Select probability value computing unit 1203, degree of belief between the described first user obtained for the physical distance between the described first user that obtains according to described physical distance acquiring unit and the second user and described degree of belief acquiring unit and the second user, calculate the select probability value between described first user and described second user, and obtain the select probability value in community between every two users thus;

Cluster unit 1204, for carrying out D2D communication node cluster according to all users in the select probability Zhi Dui community between two users every in described community.

Wherein, select probability value computing unit 1203 is connected with cluster unit 1204 with physical distance acquiring unit 1201, degree of belief acquiring unit 1202 respectively.

Alternatively, select probability value computing unit 1203 may be used for: based on distributing the Chinese restaurant's process dividing client according to dining table, calculate the select probability value between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user.

Alternatively, physical distance acquiring unit 1201 may be used for: obtain the physical distance between i-th user and a jth user, and be expressed as d (i, j); Degree of belief acquiring unit 1202 may be used for: obtain the degree of belief between i-th user and a jth user, and be expressed as p (i, j), wherein p (i, j) ∈ [0,1].

Alternatively, select probability value computing unit 1203 may be used for:

The trust distance between i-th user and a jth user is calculated: s (i, j)=-log according to the degree of belief p (i, j) between described i-th user and a jth user ₂p (i, j), obtains the matrix S that the trust distance between every two users is formed;

A jth user is selected to be expressed as the probability of its D2D communication parter i-th user:

$P(c_i=j|S,D,\mathrm{\α})=\left\{\begin{array}{cc}\frac{f_2\left(s(i,j)\right)}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},\mathrm{if}& i\≠j,\\ \frac{\mathrm{\α}}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},\mathrm{if}& i=j,\end{array}\right.$

Wherein, c _irepresent i-th user-selected D2D communication parter, the matrix that D is formed for the physical distance between every two users, α is the scalar parameter of described Chinese restaurant process, function f ₂(s (i, j)) is defined as:

$f_2\left(s(i,j)\right)=\left\{\begin{array}{cc}\frac{1}{s(i,j)},\mathrm{if}& d(i,j)\≤d_{\max }\\ 0,\mathrm{if}& d(i,j)>d_{\max }\end{array}\right.$

D _maxfor the greatest physical distance between D2D communication node.

Alternatively, degree of belief acquiring unit 1204 may be used for obtain first user and the second user between degree of belief for representing the probability of file and/or resource-sharing between two users: when described degree of belief is larger, between two users, the probability of file and/or resource-sharing is larger; Otherwise then between two users, the probability of file and/or resource-sharing is less.

Visible, in the D2D communication node clustering method based on degree of belief and physical distance provided in the embodiment of the present invention and device, consider that degree of belief and physical distance are on the impact of D2D communication node cluster, combine and consider to trust Distance geometry physical distance factor to improve the performance of D2D bunch of communication; The trust distance between two users is defined, in order to assess its impact on cluster based on degree of belief; Random process-Chinese restaurant's the process dividing client is distributed according to dining table based on a kind of, the embodiment of the present invention carries out division cluster to user, and utilize the thought of Chinese restaurant's process that distance is relevant, define some specific users and select other users as the probability of its D2D communication parter; Between the number of users upper limit of each D2D bunch and D2D communication node greatest physical distance double constraints under, obtain final D2D cluster result.As a comparison, the embodiment of the present invention gives the cluster scheme of physically based deformation distance, and is shared the performance of gain to D2D communication node cluster brought analyzed by assessment file resource.The method and apparatus of the embodiment of the present invention gives the cluster scheme based on degree of belief and physical distance in the D2D communications field, effectively achieves the lifting of throughput of system and efficiency.The method and apparatus of the embodiment of the present invention is applicable to D2D Overlay frequency spectrum share mode in cellular network and Underlay frequency spectrum share mode simultaneously.

Last it is noted that above embodiment is only in order to illustrate technical scheme of the present invention, be not intended to limit; Although with reference to previous embodiment to invention has been detailed description, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein portion of techniques feature; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the spirit and scope of various embodiments of the present invention technical scheme.

Claims (10)

1., based on a D2D communication node clustering method for degree of belief and physical distance, it is characterized in that, comprising:

Obtain the physical distance between first user and the second user;

Obtain the degree of belief between first user and the second user;

Calculate the select probability value between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user, and obtain the select probability value in community between every two users thus;

D2D communication node cluster is carried out according to all users in the select probability Zhi Dui community between two users every in described community.

2. the D2D communication node clustering method based on degree of belief and physical distance according to claim 1, it is characterized in that, the described select probability value calculated between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user comprises:

Based on distributing the Chinese restaurant's process dividing client according to dining table, calculate the select probability value between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user.

3. the D2D communication node clustering method based on degree of belief and physical distance according to claim 2, is characterized in that:

Physical distance between described acquisition first user and the second user comprises: obtain the physical distance between i-th user and a jth user, and be expressed as d (i, j);

Degree of belief between described acquisition first user and the second user comprises: obtain the degree of belief between i-th user and a jth user, and be expressed as p (i, j), wherein p (i, j) ∈ [0,1].

4. the D2D communication node clustering method based on degree of belief and physical distance according to claim 3, it is characterized in that, the described select probability value calculated between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user also comprises:

The trust distance between i-th user and a jth user is calculated: s (i, j)=-log according to the degree of belief p (i, j) between described i-th user and a jth user ₂p (i, j), obtains the matrix S that the trust distance between every two users is formed;

A jth user is selected to be expressed as the probability of its D2D communication parter i-th user:

$P(c_i=j|S,D,\mathrm{\α})=\left\{\begin{array}{ccc}\frac{f_2\left(s(i,j)\right)}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},& \mathrm{if}& i\≠j,\\ \frac{\mathrm{\α}}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},& \mathrm{if}& i\≠j,\end{array}\right.$

Wherein, c _irepresent i-th user-selected D2D communication parter, the matrix that D is formed for the physical distance between every two users, α is the scalar parameter of described Chinese restaurant process, function f ₂(s (i, j)) is defined as:

$f_2\left(s(i,j)\right)=\left\{\begin{array}{cc}\frac{1}{s(i,j)},\mathrm{if}& d(i,j)\≤d_{\max }\\ 0,\mathrm{if}& d(i,j)>d_{\max }\end{array}\right.$

D _maxfor the greatest physical distance between D2D communication node.

5. the D2D communication node clustering method based on degree of belief and physical distance according to any one of claim 1-4, is characterized in that:

Degree of belief between described first user and the second user is for representing the probability of file and/or resource-sharing between two users: when described degree of belief is larger, and between two users, the probability of file and/or resource-sharing is larger; Otherwise then between two users, the probability of file and/or resource-sharing is less;

Described method is applicable to D2D Overlay frequency spectrum share mode in cellular network and Underlay frequency spectrum share mode simultaneously.

6., based on a D2D communication node cluster device for degree of belief and physical distance, it is characterized in that, comprising:

Physical distance acquiring unit, for obtaining the physical distance between first user and the second user;

Degree of belief acquiring unit, for obtaining the degree of belief between first user and the second user;

Select probability value computing unit, degree of belief between the described first user obtained for the physical distance between the described first user that obtains according to described physical distance acquiring unit and the second user and described degree of belief acquiring unit and the second user, calculate the select probability value between described first user and described second user, and obtain the select probability value in community between every two users thus;

Cluster unit, for carrying out D2D communication node cluster according to all users in the select probability Zhi Dui community between two users every in described community.

7. the D2D communication node cluster device based on degree of belief and physical distance according to claim 6, it is characterized in that, described select probability value computing unit is used for:

Based on distributing the Chinese restaurant's process dividing client according to dining table, calculate the select probability value between described first user and described second user according to the physical distance between described first user and the second user and the degree of belief between described first user and the second user.

8. the D2D communication node cluster device based on degree of belief and physical distance according to claim 7, is characterized in that:

Described physical distance acquiring unit is used for: obtain the physical distance between i-th user and a jth user, and be expressed as d (i, j);

Described degree of belief acquiring unit is used for: obtain the degree of belief between i-th user and a jth user, and be expressed as p (i, j), wherein p (i, j) ∈ [0,1].

9. the D2D communication node cluster device based on degree of belief and physical distance according to claim 8, it is characterized in that, described select probability value computing unit is used for:

The trust distance between i-th user and a jth user is calculated: s (i, j)=-log according to the degree of belief p (i, j) between described i-th user and a jth user ₂p (i, j), obtains the matrix S that the trust distance between every two users is formed;

A jth user is selected to be expressed as the probability of its D2D communication parter i-th user:

$P(c_i=j|S,D,\mathrm{\α})=\left\{\begin{array}{ccc}\frac{f_2\left(s(i,j)\right)}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},& \mathrm{if}& i\≠j,\\ \frac{\mathrm{\α}}{{\mathrm{\Σ}}_{j\≠i}{f}_2\left(s(i,j)\right)+\mathrm{\α}},& \mathrm{if}& i\≠j,\end{array}\right.$

Wherein, c _irepresent i-th user-selected D2D communication parter, the matrix that D is formed for the physical distance between every two users, α is the scalar parameter of described Chinese restaurant process, function f ₂(s (i, j)) is defined as:

$f_2\left(s(i,j)\right)=\left\{\begin{array}{cc}\frac{1}{s(i,j)},\mathrm{if}& d(i,j)\≤d_{\max }\\ 0,\mathrm{if}& d(i,j)>d_{\max }\end{array}\right.$

D _maxfor the greatest physical distance between D2D communication node.

10. the D2D communication node cluster device based on degree of belief and physical distance according to any one of claim 6-9, is characterized in that:

Described degree of belief acquiring unit for the degree of belief between the first user that obtains and the second user for representing the probability of file and/or resource-sharing between two users: when described degree of belief is larger, between two users, the probability of file and/or resource-sharing is larger; Otherwise then between two users, the probability of file and/or resource-sharing is less;

Described device is applicable to D2D Overlay frequency spectrum share mode in cellular network and Underlay frequency spectrum share mode simultaneously.