CN104796991A - OFDMA (orthogonal frequency division multiple access) system resource distributing method based on potential game - Google Patents

Abstract

The invention discloses an OFDMA (orthogonal frequency division multiple access) system resource distributing method based on a potential game. The OFDMA system resource distributing method includes the step of (1) computing a target signal to noise ratio of a D2D user of multiplexing cellular user channel resources; (2) computing corresponding jamming radiuses of the D2D users; (3) establishing a collision matrix in sub-channel usage of each D2D user according to the jamming radius of each D2D user; (4) enabling the D2D user to play a game with other D2D users to enable an own effect function to reach the maximal value; (5) giving up to use a sub-channel resource if a conflict user exists within the jamming radius of the D2D user, and selecting an optimal sub-channel for data transmission; (6) judging whether the game is over or reaches to the maximum number of iterations or not, if not, repeating the step (5) and the step (6) until the game is over or reaches to the maximum number of iterations after updating the signal to noise ratio of the D2D user. The OFDMA system resource distributing method has the advantages that same frequency interferences in an OFDMA community are reduced, and the problem of shortage in spectrum resources is solved.

Description

Based on the resource allocation methods of the OFDMA system of gesture game

Technical field

The present invention relates to radio channel resource and distribute field, be specifically related to the resource allocation methods of a kind of OFDMA based on gesture game (OrthogonalFrequency Division Multiple Access, OFDM) system.

Background technology

Owing to having larger advantage for the demand of high rate data transmission and OFDMA technology in the robustness of the distribution of subchannel, the efficiency of frequency spectrum resource and anti-multipath fading in radio communication, people are made to produce keen interest for OFDMA technology.OFDMA technology is the evolution of OFDM technology, has been widely used in WiMAX and 3GPP technology.In OFDMA system, channel is divided into multiple mutually orthogonal subcarrier, avoids the co-channel interference of phone user in community.But introduce D2D user in the cell, the channel resource of the multiplexing phone user of D2D user, inevitably adds the co-channel interference in Iarge-scale system.There is the decline that co-channel interference can cause communication system performance in system, how to solve the problem of co-channel interference in community, become the major issue that next generation mobile communication faces.So how to have become problem demanding prompt solution in radio communication to the suppression of the co-channel interference that D2D user's Reusespectrum resource is brought.

Summary of the invention

In order to solve the deficiencies in the prior art, reducing the co-channel interference in OFDMA community, alleviating the problem of frequency spectrum resource shortage, the invention provides a kind of resource allocation methods of the OFDMA system based on gesture game.

In the mono-community of OFDMA, there is competitive relation between D2D user, the very applicable game theoretic application of this scene, therefore adopts game theoretic thought to carry out the modeling of dynamic frequency spectrum deployment problem.Game theory is applied in OFDMA community, then studied object must meet Rational Conditions and the fundamental of gambling process.Wherein Rational Conditions comprises:

(1) gambling process follows certain rule, and namely the policy selection made according to communication environment of player and action must observe certain decision rule.

(2) participant is when carrying out Tactic selection, can have a reasonably expection to the better income of acquisition.Meet this condition, each player needs the target function of the strict difinition of a maximum revenue.This condition and definable target function combine with taking action, and are all the necessary conditions of gambling process being carried out to good analysis.

The fundamental of gambling process comprises:

(1) in gambling process, there is some participants.

(2) all there is some strategies or action in participant.

(3) each participant all has the pay off function (effect function) that can represent oneself preference.

Can find out that OFDMA community can meet the requirement of game theory to case study completely according to above analysis.In OFDMA community, D2D user between compete the frequency spectrum resource of phone user, form game.

The present invention is based on the resource allocation methods of the OFDMA system of gesture game, comprise the following steps:

The target signal to noise ratio of the D2D user of multiplexing phone user's channel resource in A1, calculating OFDMA system;

A2, according to initialized target signal to noise ratio, D2D user calculates the interference radius of its correspondence;

A3, use the collison matrix of subchannel according to each D2D user of interference radius calculation of each D2D user;

Carry out game between A4, D2D user and D2D user, make the effect function of oneself reach maximum;

If A5 D2D user disturbs in radius there is conflict user, then abandon using this sub channel resource, select suboptimum subchannel transmission data;

A6, judge whether game convergence or reach maximum iteration time, if do not restrain and do not reach maximum iteration time, then, after the renewal along with D2D user's signal to noise ratio, repeat A5 ~ A6, until convergence or reach maximum iteration time.

The detailed process of A1 is, the target signal to noise ratio of D2D user

${\mathrm{\γ}}_{\mathrm{in}}=\frac{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ii}}^n}{{\mathrm{\Σ}}_{j=1,j\≠i}^D{a}_{\mathrm{jn}}p1\left(j\right)g_{\mathrm{ji}}^n+p2\left(n\right)h_{\mathrm{ni}}+N_0}$

Wherein a _inrepresent that the subcarrier of the whether multiplexing phone user n of D2D user i transmits data, a _in=1 represents multiplexing, a _in=0 represents not multiplexing, and p1 (i) represents the power of i-th D2D user, and p2 (n) represents the power of phone user n, represent the channel gain during transmitting terminal of i-th D2D user subcarrier n multiplexing to receiving terminal, represent the channel gain during transmitting terminal of jth D2D user subcarrier n multiplexing to the receiving terminal of i-th D2D user, h _nirepresent the channel gain of the n-th phone user to i-th D2D user's receiving terminal, N ₀represent white Gaussian noise.

Preferably, the interference radius of i-th D2D user for the target signal to noise ratio of this user.

Preferably, with C ∈ { 0,1} ^{d × D}represent the collison matrix of D2D user, if the transmitting terminal of D2D user j is outside the interference radius of D2D user i or i=j, then C _ij=0, otherwise C _ij=1.

In A4, potential function is

$\underset{i=1}{\overset{D}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{1}{{\mathrm{\γ}}_{i,n}}=-\underset{i=1}{\overset{D}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{{\mathrm{\Σ}}_{j=1,j\≠i}^D{a}_{\mathrm{jn}}p1\left(j\right)g_{\mathrm{ji}}^n+p2\left(n\right)h_{\mathrm{ni}}+N_0}{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ii}}^n}$

Be expressed as further

Wherein ξ _ithe policy-related (noun) item with D2D user i, ω _iit is tactful incoherent item with it; Then the effect function of D2D user i is expressed as:

$u_i={\mathrm{\ξ}}_i=-\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{\underset{j=1,j\≠i}{\overset{D}{\mathrm{\Σ}}}{a}_{\mathrm{jn}}p1\left(j\right)g_{\mathrm{ji}}^n+p2\left(n\right)h_{\mathrm{ni}}+N_0}{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ii}}^n}-\underset{m=1,m\≠i}{\overset{D}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ji}}^n}{a_{\mathrm{mn}}p1\left(m\right)g_{\mathrm{mm}}^n}.$

Target signal to noise ratio, to maximize the signal to noise ratio of D2D user for target, is converted into potential function by the present invention, solves resource optimize problem with complete gesture game.In order in reduction system because of the co-channel interference that the channel resource of the multiplexing phone user of D2D user brings, introduce the concept of interference radius, each D2D interference radius had per family centered by receiving terminal.Represent the disturbed condition caused between D2D and D2D user with interference matrix, judge whether can share sub channel resource between D2D user with this, reduce the co-channel interference in system, increase the signal to noise ratio of D2D user.

Accompanying drawing explanation

Fig. 1 is the system schematic of the mono-community of OFDMA comprising phone user and D2D user;

Fig. 2 be in the present invention D2D user to the interference radius schematic diagram centered by receiving terminal;

Fig. 3 is the resource allocation methods flow chart of the OFDMA system that the present invention is based on gesture game.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

Suppose single cell OFDMA system as shown in Figure 1, base station BS is in the center of community, radius of society is r, containing N number of phone user in community, a subcarrier in each phone user's use system, mutually orthogonal each other, sub-carrier number is all N mutually with phone user's number, and supposes that each phone user i uses the i-th corresponding sub-channels.Containing D D2D user couple in system, each D2D user to having transmitting terminal and receiving terminal, and has an interference radius centered by receiving terminal.It is changeless that the relative position of user and the state of channel are supposed in whole process.Definition D ∈ R ^{d × D}for distance matrix, wherein element d _ijrepresent D2D user to the transmitting terminal of i to D2D user to the distance between the receiving terminal of j, d _iirepresent that D2D user is to the distance between the transmitting terminal of i and receiving terminal, usually when j ≠ i, can be less than d _ji.

Sub carries allocation matrix is represented, A ∈ { 0,1} with A.Each element a in A _in∈ 0,1}, represents that the subcarrier of the whether multiplexing phone user n of D2D user i transmits data, and if multiplexing, a _in=1 otherwise a _in=0.Therefore, D2D user can by the i-th every trade vector of matrix A to the subcarrier service condition of i represent, suppose that row vector can not be null vector here.

Definition G ∈ R ^{d × D × N}with H ∈ R ^{n × D}represent subscriber channel gain matrix, the wherein element of G represent the channel gain during transmitting terminal of i-th D2D user subcarrier n multiplexing to the receiving terminal of a jth D2D user, under normal circumstances the element h of H _ijrepresent the channel gain of i-th phone user to jth D2D user's receiving terminal.Equally, matrix P1 ∈ R ^drepresent the power division that D2D user is right, p1 (i) represents the power of i-th D2D user, and is less than maximum power restriction P _max.The power matrix P2 ∈ R of the phone user in community ⁿrepresent, p2 (n) represents the power of phone user n, and is less than maximum power restriction P _max.Then for the D2D user i of the channel resource of multiplexing phone user n, its signal to noise ratio SINR can be expressed as: ${\mathrm{\γ}}_{\mathrm{in}}=\frac{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ii}}^n}{{\mathrm{\Σ}}_{j=1,j\≠i}^D{a}_{\mathrm{jn}}p1\left(j\right)g_{\mathrm{ji}}^n+p2\left(n\right)h_{\mathrm{ni}}+N_0},$ N ₀it is all identical for representing white Gaussian noise and supposing all links.

Definition r _ibe the interference radius of i-th D2D user, only consider that simple method (only considering path loss) carrys out the interference radius of estimating subscriber's i, by determine, λ is path loss index, for target signal to noise ratio.

Use Distance matrix D defined above, for D2D user i, if and a _jn=0, namely D2D user j does not use subcarrier n to carry out the transmission of data, then D2D user i can the subcarrier of multiplexing phone user n, if but a _jn=1, then D2D user i avoids the subcarrier of multiplexing phone user n.

With Matrix C ∈ { 0,1} ^{d × D}represent the collison matrix of D2D user, if the transmitting terminal of D2D user j is outside the interference radius of D2D user i or i=j, then Elements C _ij=0, otherwise C _ij=1.

For Fig. 2, list the naive model with 4 D2D users herein.Can see that D2D user 2 and other any D2D are with there is not interference per family.The transmitting terminal of D2D user 4 is in the interference radius of D2D user 1 and D2D user 3, therefore all causes stronger interference to 1 and 3, disposes 1 at interference half drive matrix of correspondence.User 1 and 3 does not form interference mutually, and therefore the interference collison matrix of this naive model is $C=\left[\begin{array}{cccc}0& 0& 0& 1\\ 0& 0& 0& 0\\ 0& 0& 0& 1\\ 0& 0& 0& 0\end{array}\right].$

The potential function of D2D user meets following characteristic:

(1) potential function V is expressed as V=g _k(ξ _k, ω _k), wherein ξ _kthe item relevant with the strategy of user k, and ω _krepresent the item irrelevant with the strategy of user k, g _kit is a monotonically increasing function.

(2) V is for all user k being increasing function about signal to noise ratio.This characteristic and gesture game, without direct relation, are exist in order to ensure maximizing potential function can reach the object of maximization user signal to noise ratio.

If can find the function meeting above two conditions simultaneously, then select this function as the effect function of game, this just forms common gesture game.Further, if for any one user, relational expression V=ξ _k+ ω _kset up, then can make u _k=ξ _k, so just can form a complete gesture game.

Potential function is defined as the negative of the inverse of all user's signal to noise ratios, is shown below: $V=-\underset{i=1}{\overset{D}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{1}{{\mathrm{\γ}}_{i,n}}=-\underset{i=1}{\overset{D}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{{\mathrm{\Σ}}_{j=1,j\≠i}^D{a}_{\mathrm{jn}}p1\left(j\right)g_{\mathrm{ji}}^n+p2\left(n\right)h_{\mathrm{ni}}+N_0}{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ii}}^n,}$ Continue to turn to: ξ _ithe policy-related (noun) item with D2D user i, ω _iit is tactful incoherent item with it.

Then the effect function of D2D user i is expressed as:

$u_i={\mathrm{\ξ}}_i=-\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{\underset{j=1,j\≠i}{\overset{D}{\mathrm{\Σ}}}{a}_{\mathrm{jn}}p1\left(j\right)g_{\mathrm{ji}}^n+p2\left(n\right)h_{\mathrm{ni}}+N_0}{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ii}}^n}-\underset{m=1,m\≠i}{\overset{D}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ji}}^n}{a_{\mathrm{mn}}p1\left(m\right)g_{\mathrm{mm}}^n}.$

D2D user in system carries out the competition of sub-carrier resources, user i selects the sub channel resource making its effect function reach maximum at every turn, whether the value judging the i-th row correspondence position on this subchannel in collison matrix is 1, if then represent that D2D user disturbs existence conflict user in radius, need to abandon using this sub channel resource, select suboptimum subchannel.Each D2D performs this operation until game restrains or reaches maximum iteration time with circulating per family.

Technological means disclosed in the present invention program is not limited only to the technological means disclosed in above-mentioned execution mode, also comprises the technical scheme be made up of above technical characteristic combination in any.

Claims (5)

1. based on the resource allocation methods of the OFDMA system of gesture game, it is characterized in that, comprise the following steps:

The target signal to noise ratio of the D2D user of multiplexing phone user's channel resource in A1, calculating OFDMA system;

A2, according to initialized target signal to noise ratio, D2D user calculates the interference radius of its correspondence;

A3, set up according to the interference radius of each D2D user the collison matrix that each D2D user uses subchannel;

Carry out game between A4, D2D user and D2D user, make the effect function of oneself reach maximum;

If A5 D2D user disturbs in radius there is conflict user, then abandon using this sub channel resource, select suboptimum subchannel transmission data;

A6, judge whether game convergence or reach maximum iteration time, if do not restrain and do not reach maximum iteration time, then along with the renewal of D2D user's signal to noise ratio, repeat A5 ~ A6, until convergence or reach maximum iteration time.

2. the resource allocation methods of the OFDMA system based on gesture game according to claim 1, is characterized in that, the detailed process of A1 is, the target signal to noise ratio of D2D user

${\mathrm{\γ}}_{\mathrm{in}}=\frac{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ii}}^n}{{\mathrm{\Σ}}_{j=1,j\≠i}^D{a}_{\mathrm{jn}}p1\left(j\right)g_{\mathrm{ji}}^n+p2\left(n\right)h_{\mathrm{ni}}+N_0}$

Wherein a _inrepresent that the subcarrier of the whether multiplexing phone user n of D2D user i transmits data, a _in=1 represents multiplexing, a _in=0 represents not multiplexing, and p1 (i) represents the power of i-th D2D user, and p2 (n) represents the power of phone user n, represent the channel gain during transmitting terminal of i-th D2D user subcarrier n multiplexing to receiving terminal, represent the channel gain during transmitting terminal of jth D2D user subcarrier n multiplexing to the receiving terminal of i-th D2D user, h _nirepresent the channel gain of the n-th phone user to i-th D2D user's receiving terminal, N ₀represent white Gaussian noise.

3. the resource allocation methods of the OFDMA system based on gesture game according to claim 2, is characterized in that, the interference radius of i-th D2D user for the target signal to noise ratio of this user.

4. the resource allocation methods of the OFDMA system based on gesture game according to claim 3, is characterized in that, C ∈ { 0,1} ^{d × D}represent the collison matrix of D2D user, if the transmitting terminal of D2D user j is outside the interference radius of D2D user i or i=j, then C _ij=0, otherwise C _ij=1.

5. the resource allocation methods of the OFDMA system based on gesture game according to claim 1, is characterized in that, in A4, potential function is

$V=-\underset{i=1}{\overset{D}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{1}{{\mathrm{\γ}}_{i,n}}=-\underset{i=1}{\overset{D}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{{\mathrm{\Σ}}_{j=1,j\≠i}^D{a}_{\mathrm{jn}}p1\left(j\right)g_{\mathrm{ji}}^n+p2\left(n\right)h_{\mathrm{ni}}+N_0}{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ii}}^n}$

Be expressed as further

Wherein ξ _ithe policy-related (noun) item with D2D user i, ω _iit is tactful incoherent item with it; Then the effect function of D2D user i is expressed as:

$u_i={\mathrm{\ξ}}_i=-\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{\underset{j=1,j\≠i}{\overset{D}{\mathrm{\Σ}}}{a}_{\mathrm{jn}}p1\left(j\right)g_{\mathrm{ji}}^n+p2\left(n\right)h_{\mathrm{ni}}+N_0}{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ii}}^n}-\underset{m=1,m\≠i}{\overset{D}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\frac{a_{\mathrm{in}}p1\left(i\right)g_{\mathrm{ji}}^n}{a_{\mathrm{mn}}p1\left(m\right)g_{\mathrm{mm}}^n}.$