CN103402212B - Macrocell user MUE selects to fly the phone user FUE method assisting relaying - Google Patents

Abstract

The invention provides a kind of macrocell user MUE to select to fly the phone user FUE method assisting relaying, comprise the steps: the first step: multiple MUE and multiple FUE take cooperation transmission mode, and specify slot assignment protocol；Second step: calculate the effectiveness that different FUE is each MUE relaying；3rd step: each MUE selects FUE relay collection according to the order of sequence according to effectiveness parameter；4th step: selected by multiple MUE if there is FUE, travels through all possible selection assembled scheme, MUE effective increment is amassed maximum scheme and is defined as optimal strategy, and determine the relay selection set of each MUE according to described strategy.The present invention, in the exclusive network of the frequency spectrum that there is multiple FUE, instructs multiple MUE effectively to select FUE to assist relaying, takes into account the fairness between MUE simultaneously, compare fully intermeshing algorithm and have relatively low operand and good performance.

Description

Macrocell user MUE selects to fly the phone user FUE method assisting relaying

Technical field

The present invention relates to communication technical field, in particular it relates to a kind of macrocell user MUE selects to fly the phone user FUE method assisting relaying.

Background technology

Based on people for the requirement of more low energy consumption in higher wireless transmission rate, wider wireless coverage and " green radio ", fly honeycomb (Femtocell) and attract wide attention in academic and industrial quarters.Fly cellular access point to arrange at home, help the user access core network away from macro base station as relaying, decrease the energy consumption of macrocellular (Macrocell) user.But, in order to preserve self capacity and back haul link, many times fly honeycomb owner tendency and take closed access in up-link, for instance in the exclusive network of macrocellular-fly cellular frequency spectrum.When cooperation policy taked by macrocellular-fly honeycomb, if a macrocell user (MUE) moves to edge, macro cells, but close to flying cellular coverage, it is possible to employ some channel conditions to fly phone user (FUE) preferably and help relaying.Owing to flying by wired connection between cellular access point (FAP) and macrocell base stations (MBS), MUE can be assisted relay data to FAP by FUE, thus realizing data transmission.Which overcome MUE directly to MBS transmit time bad channel quality problem, help MUE save energy consumption.Meanwhile, these provide the FUE of the service part-time obtaining in MUE transmission structure to transmit the data of oneself as return.Such modality for co-operation is MUE and the FUE situation creating win-win.

In recent years, cause, about MUE-FUE collaborative problem, the research that people are extensive, the stability of cooperation and service quality it is critical only that a set of careful and effective resource allocation mechanism.Find by prior art documents, LinjieDuan, JianweiHuang and BiyingShou is by " Economicsoffemtocellserviceprovision " (fly honeycomb and provide the economics of service) delivered on IEEETransactionsonMobileComputing in 2013 in a literary composition, by the subgame perfect equilibrium of Stackelberggame, have studied mobile operator on current macrocellular service, introduce the Economic Motivation flying cellular service.

But above-mentioned technology is not while considering to maximize all MUE overall interests, it is considered to the fairness between MUE.The Nash Bargaining problem of consideration fairness is NP-hard problem, and existing exhaust algorithm, because amount of calculation is excessive, is difficult in actual environment and realizes.

Summary of the invention

For defect of the prior art, it is an object of the invention to provide a kind of macrocell user MUE and select to fly the phone user FUE method assisting relaying, it is ensured that the maximized basis of overall interests is distributed the strategy of multiple FUE liberally.

According to an aspect of the present invention, it is provided that a kind of macrocell user MUE selects to fly the phone user FUE method assisting relaying, it is characterized in that, comprises the steps:

The first step: multiple MUE and multiple FUE take cooperation transmission mode, and specify slot assignment protocol；

Second step: calculate the effectiveness that different FUE is each MUE relaying；

3rd step: each MUE selects FUE relay collection according to the order of sequence according to effectiveness parameter；

4th step: selected by multiple MUE if there is FUE, travels through all possible selection assembled scheme, MUE effective increment is amassed maximum scheme and is defined as optimal strategy, and determine the relay selection set of each MUE according to described strategy.

Preferably, cooperation transmission mode in the described first step specifies that each time slot is divided into three parts: MUE is to the part α of FUE broadcast data, FUE side MUE relays to and flies cellular access point FAP part (1-α) β, and FUE receives MUE and compensates the part (1-α) (1-β) for passing oneself data.

Preferably, in described second step, in the exclusive network of note frequency spectrum, the number that number is M, FUE of MUE is N, remembers that some MUE therein is MUE_m, m=1,2 ... M, some FUE are FUE_n, n=1,2 ... N, according to the transfer rate after relaying, calculate each FUE and help the value of utility of each MUE relaying, MUE_mSelect FUE relay collectionTime effectiveness equal to individually employing relayingEffective sum, calculate FUE_nFor MUE_mDistance d_m,n, obtain FUE_nFor MUE_mEffectiveness-distance product

Preferably, in described 3rd step, each MUE is according to distance d_m,nAscending selection FUE, and calculate cumulative utility-distance product successivelyEach MUE finds a fulcrum μ that can be evenly dividing in network effectiveness-distance product summation_m, each MUE_mObtain a FUE and relay subsetMakeIn the cumulative utility-distance product of all FUE be not more than μ_m。

Compared with prior art, the present invention has following beneficial effect:

In the exclusive network of the frequency spectrum that there is multiple FUE, instruct multiple MUE effectively to select FUE to assist relaying, take into account the fairness between MUE simultaneously, compare fully intermeshing algorithm and there is relatively low operand and good performance.

Accompanying drawing explanation

By reading detailed description non-limiting example made with reference to the following drawings, the other features, objects and advantages of the present invention will become more apparent upon:

Fig. 1 is the flow chart of the present invention；

Fig. 2 is the macrocellular of the present invention and flies the signal of honeycomb scene, and the contrast situation of the non-approach to cooperation of MUE and FUE (individual transmission) and approach to cooperation (MUE employs FUE cooperating relay)；

The result of MUE relay selection when Fig. 3 is to adopt this method in certain example；

The result of MUE relay selection when Fig. 4 is to adopt fully intermeshing method in certain example；

MUE effective increment and the numerical value contrast adopting fully intermeshing optimum or during random selection method when Fig. 5 adopts this method；

Fig. 6 is the impact that FUE quantity is long-pending on MUE average utility increment.

Detailed description of the invention

Below in conjunction with specific embodiment, the present invention is described in detail.Following example will assist in those skilled in the art and are further appreciated by the present invention, but do not limit the present invention in any form.It should be pointed out that, to those skilled in the art, without departing from the inventive concept of the premise, it is also possible to make some deformation and improvement.These broadly fall into protection scope of the present invention.

Selecting to fly phone user FUE referring to Fig. 1, macrocell user MUE of the present invention assists the method for relaying to comprise the following steps:

Step one, multiple MUE and multiple FUE constitute the exclusive network of frequency spectrum, adopt cooperation transmission mode, and specify that time slot uses agreement between MUE, FUE.MBS and FAP is both connected in core net (in figure step S01).

MBS, FAP and Covering domain thereof, system model such as Fig. 1 of multiple MUE and multiple FUE composition.When MUE-FUE adopts modality for co-operation, each MUE/FUE time slot is divided into the hop α of three part: MUE to FUE, FUE helps MUE relay portion (1-α) β, and MUE compensates FUE for passing the part (1-α) (1-β) of oneself data.Data division is transmitted to FUE, the peritropous FUE broadcast data of each MUE at MUE.Broadcast data adopts the mode of frequency division multiplexing, and each FUE only receives the data of corresponding frequency band.In FUE relay portion, FUE adopts forward direction to amplify (AF, amplifyandforward) mode, and its data received of normalization, the principle further according to first in first out transfers data to FAP.

Step 2, calculates effectiveness and relevant parameter (in figure step S02) that different FUE is each MUE relaying.

Consider that each MUE knows about all FUE in network and helps the full detail of its relaying, for instance through-put power, channel quality and noise level etc..Different FUE help the effectiveness of MUE relaying to be different, such as FUE_nSide MUE_mThe effectiveness of relaying is

$U_m^n=\mathrm{\τ}{B}_n\log (1+\frac{{\left|{\mathrm{\α}}_{m,n}{h}_{m,n}{h}_{n,a}\right|}^2{P}_m}{{|1+{\mathrm{\α}}_{m,n}{h}_{n,a}|}^2{\mathrm{\σ}}^2}).$ Formula one

Wherein, τ=α (1-α) β is the time coefficient after cooperation, B_nIt is FUE_nBandwidth during side MUE relaying, α_m,nIt is the normalization factor of FUE section, h_m,n、h_n,aIt is MUE respectively_mTo FUE_nAnd FUE_nTo the channel gain of FAP, P_mIt is MUE_mThrough-put power.Here we assume that noise is additive white Gaussian noise, its variance is σ².Owing to MUE adopts frequency division multiplexing mode and FUE to take independent channel, MUE when relay transmission_mIn FUE relay collectionUnder effectiveness equal to individually employing relayingEffective sum:

Formula two

In order to balance individual interest and overall fairness, we propose Nash Bargaining solution for relay selection problem, it may be assumed that

Formula three

WhereinIt it is FUE setOne be likely to segmentation, U_mIt is MUE under splitting at this_mEffectiveness.d_mIt is the MUE when bargaining unsuccessfully_mEffectiveness, be equal to MUE at this_mDirectly to MBS transmit time data transfer rate:

$d_m=B_m\log (1+\frac{{\left|h_{m,b}\right|}^2{P}_m}{{\mathrm{\σ}}^2})$ Formula four

Wherein B_mIt is MUE_mDirectly bandwidth during transmission, h_m,bIt is MUE_mChannel gain to MBS.

Each MUE calculates arbitrary FUE according to formula one_nHelp the effectiveness of its relayingIn European geometry category, bargaining game can be expressed with spatial game theory.Calculate each FUE_nFor MUE_mDistance d_m,n:

$d_{m,n}=\frac{1/U_m^n}{\underset{m}{\mathrm{\Σ}}(1/U_m^n)}.$ Formula five

The concept of the moment being similar in lever system, we obtain arbitrary relaying FUE_nFor MUE_mEffectiveness-distance product:

${\mathrm{\φ}}_m^n=U_m^n\·d_{m,n}.$ Formula six

Step 3, each MUE selects FUE relay collection (in figure step S03) according to the order of sequence according to parameter.

Each MUE is according to distance d_m,nAscending selection FUE, and calculate cumulative utility-distance product successively, i.e. distance MUE_mLess than FUE_nThe effectiveness-distance product sum of all FUE:

Formula seven

Being analogous to lever system, each MUE needs to find a fulcrum that can be evenly dividing in network effectiveness-distance product summation, and this fulcrum meets:

Formula eight

Each MUE determines its position of the fulcrum according to above formula.Therefore each MUE_mObtain a FUE and relay subsetSo thatCumulative utility-the distance product of middle FUE is not more than μ_m, it may be assumed that

Formula nine

Step 4, is selected by multiple MUE if there is FUE, travels through all possible selection assembled scheme, and optimal strategy is that MUE effective increment amasss maximum scheme (in figure step S04).

The long-pending P_UG of definition maximum utility increment^*=0.Any FUE is belonged to more than oneEnumerate all possible segmentation combination, circulation:

Calculate the long-pending P_UG of the effective increment in current segmentation situation.

If P_UG > P_UG^*, then P_UG is made^*=P_UG, and to update optimal strategy be current dividing method.

Circulate complete

Finally, according to optimal strategy, each MUE determines that its relaying choice set closes

As in figure 2 it is shown, be the macrocellular of the present invention and fly honeycomb scene schematic diagram.Wherein three MUE(and FUE) adopt non-modality for co-operation, three MUE(and FUE) adopt modality for co-operation.

In non-modality for co-operation, MUE utilizes whole time slot directly to pass data to MBS, and FUE must wait.In modality for co-operation, the front α part MUE of each time slot transmits to FUE broadcast, ensuing (1-α) beat portion FUE helps MUE relay data to FAP, and the MUE of last (1-α) (1-β) part FUE compensates and transmits oneself data.

Fig. 3 to Fig. 6 is result and the parameter comparison of multiple relay selection method under certain example.

The ambient parameter of this example is:

6 MUE and 9 FUE be evenly distributed in (0,0) be starting point 1 × 1 square geographical coverage area in, MBS in (2,2) FAP in (0.5,0.5).The transmission bandwidth of each MUE is that 10, FUE transmission bandwidths are obtained by the bandwidth being evenly dividing service MUE.Through-put power P_m=1, noise level σ²=1, parameter alpha=0.5, parameter beta=0.5.Usually, the channel gain between each transmission pair is inversely proportional to their spacing.In order to highlight the transmission quality between FUE-FAP, the channel gain between them is multiplied by between one 0 to 10 the equally distributed factor.Except this method, this example also contemplates two kinds of control methods: fully intermeshing method and random choice method.Fully intermeshing method refers to for the Nash Bargaining solution in formula three, travels through all possible selection assembled scheme, finds maximum MUE effective increment and amasss, and the selection scheme recording correspondence is optimal strategy.Owing to traveling through all combinations, the higher (M of computation complexity of fully intermeshing method^NSecondary).Random choice method refers to and distributes relay collection for each MUE randomly, therefore only needs primary distribution.

Fig. 3 and Fig. 4 compared for this method and the Different Results of fully intermeshing FAXIA MUE relay selection.Under this method, MUE₂、MUE₃And MUE₄The FUE selected relays number respectively 2,2 and 2；And fully intermeshing FAXIA MUE₂、MUE₃And MUE₄The FUE selected relays number respectively 1,2 and 3.MUE₁、MUE₅And MUE₆Relay selection under two kinds of methods is completely the same.

As it is shown in figure 5, the effectiveness of each MUE has notable difference when adopting distinct methods.MUE under this method₂Effective increment higher than fully intermeshing method, fully intermeshing FAXIA MUE₃And MUE₄Effective increment higher than this method, and MUE under this method₁、MUE₅And MUE₆Effective increment be equal to fully intermeshing method.But for random choice method, because MUE₁Obtain too much FUE to assist, so there being higher effective increment, and MUE₂To MUE₆Effective increment be negative value.

By changing the quantity of FUE respectively, the present embodiment is also tested for the impact that this parameter is long-pending on MUE effective increment.As shown in Figure 6, the quantity of fixing MUE is 4, makes the quantity of FUE rise to 9 from 4, obtains the long-pending curve with FUE number change of MUE average utility increment under three kinds of methods.Such as, in figure, coordinate is that representing of (6,0.59) is about 0.59 when quantity respectively 4 and 6, the MUE average utility increments of MUE, FUE are long-pending.In figure profitable result be all by repeating to test the average of the result that obtains for 100 times.

When the quantity of FUE increases, the MUE effective increment of this method and fully intermeshing FAXIA is long-pending all to be increased to some extent.Before the quantity of FUE reaches 5, the rate of increase of this method is relatively slow, then dramatically increases afterwards.After the quantity of FUE increases to 5, the gap that this method is amassed with fully intermeshing FAXIA MUE effective increment constantly reduces.When there being 9 FUE, the MUE effective increment of this method is amassed and is reached about the 90% of fully intermeshing method.And for random choice method, its MUE effective increment is long-pending hovers all the time near 0.

Above specific embodiments of the invention are described.It is to be appreciated that the invention is not limited in above-mentioned particular implementation, those skilled in the art can make various deformation or amendment within the scope of the claims, and this has no effect on the flesh and blood of the present invention.

Claims (1)

1. a macrocell user MUE selects to fly the phone user FUE method assisting relaying, it is characterised in that comprise the steps:

The first step: multiple MUE and multiple FUE take cooperation transmission mode, and specify slot assignment protocol；

Second step: calculate the effectiveness that different FUE is each MUE relaying；

3rd step: each MUE selects FUE relay collection according to the order of sequence according to effectiveness parameter；

4th step: selected by multiple MUE if there is FUE, then travel through all possible selection assembled scheme, MUE effective increment is amassed maximum scheme and is defined as optimal strategy, and determine the relay selection set of each MUE according to described optimal strategy；

Cooperation transmission mode in the described first step specifies that each time slot is divided into three parts: MUE is to the part α of FUE broadcast data, FUE helps MUE to relay to part (1-α) β flying cellular access point FAP, and FUE receives MUE and compensates the part (1-α) (1-β) for passing oneself data, wherein, α, β are parameter；

In described second step, in the exclusive network of note frequency spectrum, the number that number is M, FUE of MUE is N, remembers that some MUE therein is MUE_m, m=1,2 ... M, some FUE are FUE_n, n=1,2 ... N, according to the transfer rate after relaying, calculate each FUE and help the value of utility of each MUE relaying, MUE_mSelect FUE relay collection N_mTime effectiveness equal to individually employing relaying FUE_n(n∈N_m) effective sum, calculate FUE_nFor MUE_mDistance d_m,n, obtain FUE_nFor MUE_mEffectiveness-distance product；

In described 3rd step, each MUE is according to distance d_m,nAscending selection FUE, and calculate each MUE of the cumulative utility-distance product fulcrum μ finding can be evenly dividing in network effectiveness-distance product summation successively_m, each MUE_mObtain a FUE and relay subset C_m, make C_mIn the cumulative utility-distance product of all FUE be not more than μ_m。