CN104270768B - Frequency spectrum sharing method based on Stark Burger game in cooperative cognitive wireless network - Google Patents

Abstract

The invention discloses the frequency spectrum sharing method based on Stark Burger game in a kind of cooperative cognitive wireless network, including step：Information gathering stage, game stage, data transmission phase.The present invention combines principal and subordinate's characteristic of primary and secondary user in cognitive radio networks, will be using primary user as leader, and the cognitive transmission user of multiple expense cooperations is incorporated into frequency spectrum share for the two-stage Stark Burger betting model of subordinate.Consider that primary user is limited due to self-energy, what primary user transmitted data consumed energy to it when being in different-energy level takes notice of that degree is different, and then influence its decision-making during frequency spectrum share.(FDMA is accessed using two benches frequency division multiple access, frequency division multiple access) cooperation pass-through mode, ensure the continuity of cognitive user communication, frequency spectrum resource is distributed by dynamic game, and more preferable incentive action is played to cognitive user.Take into full account that primary and secondary user maximizes the demand of itself effectiveness, reach the situation of primary and secondary user " doulbe-sides' victory ", improve the utilization rate of frequency spectrum.

Description

Frequency spectrum sharing method based on Stark Burger game in cooperative cognitive wireless network

Technical field

The invention belongs to cognitive radio networks communication technical field, the more particularly to primary and secondary based on Stark Burger game Cooperation among users spectrum sharing mechanisms.

Background technology

With developing rapidly for wireless communication technology, increasing wireless device and application are widely used, people couple The demand of frequency spectrum is more and more, causes available Radio Spectrum Resource growing tension, frequency spectrum scarcity problem oneself turn into and realize The bottleneck of wireless communication technology sustainable development.Existing frequency spectrum resource allocation method uses static spectral allocation strategy, Frequency spectrum resource is divided into and authorizes frequency range and a small amount of unauthorized frequency range, the user referred to as authorized user of frequency spectrum is assigned to, and It is not allocated to user's referred to as unauthorized user of frequency spectrum.Authorized user specially enjoys the frequency spectrum that it is assigned on frequency range is authorized, its Its user can not be shared.And the unallocated unauthorized user to frequency spectrum can only go competition a small amount of in short supply on frequency range is authorized Unlicensed spectrum.FCC (FCC) carries out substantial amounts of investigation to the service condition of each frequency range and found, by In authorized user frequency spectrum is used over time and space it is discontinuous so that the allocated frequency spectrum resource occurs in that certain journey That spends is idle, and overall utilization ratio only has 15%-85%.In order to solve the problem of availability of frequency spectrum is low, design one kind can Dynamic sensing and accurately access the technology of the authorization channel being not used by and be necessary.Cognitive radio (CR, Cognitive Radio) technology arises at the historic moment, it has also become the crucial skill of radio spectrum resources utilization rate is improved in next generation network Art.In cognitive radio networks, possess and authorize the user of frequency spectrum to be referred to as primary user (PU, primary user), without awarding The user of power frequency spectrum is referred to as cognitive user (SU, secondary user).

The frequency spectrum service condition opportunistic that cognitive user passes through real-time perception primary user in conventional cognitive radio network Idle frequency spectrum is accessed, because the time variation of usable spectrum, diversity and otherness cause frequency spectrum perception in cognitive radio networks There is high dynamic and complexity in technology.Meanwhile, cognitive user must be immediately exited from when primary user returns, and frequency spectrum is handed over Primary user is returned, so causes the communication quality of cognitive user cannot be guaranteed.Comparatively speaking primary user has spectrum management Power, can be leased to cognitive user by untapped frequency spectrum according to the situation of itself and use, therefrom collect the frequency spectrum of definite remuneration Way to manage is more simple in the realization of technology, and primary user asks cognitive user to assist it to pass to improve the communication performance of oneself Transmission of data, as return, a part of frequency spectrum of oneself is leased to the frequency spectrum share mode that cognitive user uses and attracted by primary user The extensive concern of academia and industry.

In recent years, the achievement in research on cooperative cognitive radio net frequency spectrum share is a lot, in document H.B.Wang, L.Gao,X.Y.Gan,X.B.Wang,E.Hossain.Cooperative spectrum sharing in cognitive radio networks:A game-theoretic approach.In Proceedings of IEEE International Author in Conference on Communications, IEEE, Cape Town, South Africa, pp.23-27,2010. The frequency spectrum share problem between a primary user and multiple cognitive users is considered, primary user is by choosing the multiple of the condition of being adapted to Cognitive user assists it to transmit data, and a part of frequency spectrum of oneself is distributed into cognitive user as return primary user transmits oneself Data.The utility function of primary user to maximize its transmission rate, the utility function of cognitive user not only with its transmission rate It is used for the consumed energy of transmission with it about also relevant.Each cognitive user is assigned to be cooperated therewith using the time of PU frequency spectrums The contribution done is directly proportional, it is ensured that the fairness between cognitive user, and good incentive action is played to cognitive user.But not Consider lower influence of the primary user to self transmission institute's consumed energy to its network utility of different-energy level.Document B.Cao, J.W.Mark,Q.Zhang,R.Lu,X.Lin,and S.Shen,“On optimal communication strategies For cooperative cognitive radio networking, " in Proc.IEEE INFOCOM, Apr.2013. works Person have studied the influence under the consumption of primary user's different-energy level and power to network utility under several different repetition policies.Should Cognitive user is by a secondary access point centralized Control in scheme, and the success of scheme is built upon secondary access point and all are recognized On the basis of knowing user and being all justice, and the frequency spectrum resource distribution of primary user uses fixed allocation mode in the program, i.e., respectively Time slot shared by stage of communication, the number of stages according to needed for repetition policy is evenly distributed.This is inefficient, is also simultaneously Irrational, because cognitive user can only go to compete the frequency spectrum resource of fixed allocation, the effectiveness of cognitive user will be by very big Limitation so that also just be unfavorable for excitation cognitive user preferably participate in cooperation.At the same time, in above-mentioned two scheme In, cognitive user can only could access the data of spectrum transmissions oneself after primary user completes data transfer, and cognitive user is led to The continuity of letter cannot be ensured.

The content of the invention

The deficiency of the prior art for more than, it is an object of the invention to provide a kind of communication matter for ensureing primary user Amount, improves network spectrum utilization rate.Technical scheme is as follows：Stark Burger is based in cooperative cognitive wireless network The frequency spectrum sharing method of game, the master network of the cooperative cognitive wireless network is by multiple primary user PU and a base station BS structure Into infrastructure network, primary user PU communicates in TDMA modes with base station BS, base station BS to each primary user PU distribute when Gap is T, it is assumed that the spectral bandwidth of each primary user is W, and cognition network includes N number of cognitive transmission user ST_i(i=1, 2 ..., N) and cognitive reception user SR_iIt is right.Comprise the following steps：

101st, by the frequency spectrum share between primary user PU and secondary user using two benches FDMA cooperation pass-through modes, primary user The frequency spectrum of oneself is divided into τ W and two mutually orthogonal sub-bands of (1- τ) W by PU；

102nd, base station BS estimates the channel gain G of link between primary user PU and base station BS respectively_PBAnd cognitive transmission user ST_i The channel gain of link between base station BSCognition sends user ST_iEstimate that primary user PU sends user ST with cognitive_iBetween chain The channel gain on roadCognition receives user SR_iEstimation is cognitive to send user ST_iUser SR is received with cognition_iBetween link letter Road gainAnd by the channel gain G of estimation_PB, channel gainChannel gainAnd channel gainIt is transmitted to Primary user PU；

103rd, set up using primary user PU as leader, it is multiple it is noncooperative it is cognitive send user STs for subordinate two-stage this Plutarch Burger betting model.Initially set up primary user PU utility function Wherein, U_PD,U_PCIt is primary user PU respectively in the effectiveness for direct transferring with being obtained under cooperation mode, R_PDIt is the handling capacity that PU direct transfers, E_PDIt is PU direct transfers the energy of consumption, R_PCFor the handling capacity under PU cooperation modes, E_PCThe energy of consumption, I are transmitted under cooperation mode for PU (E_P0) it is that PU existing energy level transmits consumed energy to PU and takes notice of degree function；Then cognitive transmission user ST is set up_i's Utility function is：WhereinFor ST_iThe handling capacity of acquisition,For ST_iDisappear for PU transmission data The unit cost of energy consumption,For ST_iHelp the energy of PU forwarding data consumption.Using Stark Burger game method to (1) (2) game is carried out, PU estimates optimal frequency spectrum distribution coefficient τ^*With optimal transmission powerIf τ^*=1, primary user to The information of frequency spectrum is not leased in all cognitive user broadcast, conversely, primary user willAll cognitive send are broadcast to use Family, primary user's selection can make the maximized cognitive user's collection that sends of its utility function as relay node user, and primary user is to institute There is relay node user to feed back a reference information, each selected cognitive transmission user calculates oneself according to reference information and used In the transimission power of cooperation

104th, when primary user selects the mode that direct transfers, primary user uses the whole frequency spectrum resources transmission data of oneself, cognition hair Send user not help primary user to transmit data, while cognitive send user because frequency spectrum is arrived in failed lease, cannot also transmit The data of oneself；If primary user selects cooperation mode, primary user is bandwidth in first sub-band with cognitive transmission user For τ^*The data of the upper cooperation transmission primary users of W, each cognition for being selected as relaying sends user in second sub-band i.e. with a width of (1-τ^*) W is upper transmits the data of oneself in the frequency range for distributing to it in the way of OFDM.

The transmission consumed energy takes notice of degree function I (E_P0) expression formula be：

Wherein, E_P0For PU existing energy,For the critical value of the existing energy levels of PU.

Advantages of the present invention and have the beneficial effect that：

The present invention considers takes notice of degree to its network utility transmission consumed energy under primary user's different-energy level The influence brought, cognitive user transmits the continuity of oneself data and the dynamically distributes problem of bandwidth between primary and secondary user.Fill Divide the demand for considering that primary and secondary user maximizes oneself effectiveness, excite primary and secondary user to participate in the enthusiasm come in cooperation, it is ensured that be main The communication quality of user, improves network spectrum utilization rate.Simultaneously using two benches FDMA cooperation pass-through modes, it is ensured that cognition is used The continuity of family communication, frequency spectrum uses dynamically distributes, preferably excites cognitive user to participate in cooperation.Realize primary and secondary user The maximization of effectiveness, reaches the situation of " doulbe-sides' victory ", and network spectrum efficiency is further improved.

Brief description of the drawings

Fig. 1 show the system model and frequency spectrum distribution diagram of preferred embodiment of the present invention cooperative cognitive radio net；

Fig. 2 is the relay selection algorithm in the present invention；

Fig. 3 is realizes the game flow chart of frequency spectrum share in the present invention；

Fig. 4 is flow stages general diagram of the invention.

Embodiment

Providing an infinite embodiment below in conjunction with the accompanying drawings, the invention will be further elaborated.But should manage Solution, these descriptions are example, and are not intended to limit the scope of the present invention.In addition, in the following description, eliminating to known The description of structure and technology, to avoid unnecessarily obscuring idea of the invention.

General thought of the present invention is：In cognition network does not have the cognitive radio networks of central control unit, master is introduced The existing energy level function of user, the function characterize primary user be in transmit consumed energy to it under different-energy level take notice of journey Degree, more its of the existing energy of primary user takes notice of that degree is lower to transmission institute consumed energy, conversely, then higher.Frequency spectrum resource The FDMA modes that use are divided, the frequency spectrum of oneself is divided into two orthogonal sub-bands by primary user, and first sub-band is used to lead User communicates under cognitive user cooperation, and second subband allocation is used for the communication of oneself, two sub-bands to cognitive user Bandwidth is by primary user and cognitive sends between user by game by primary user's dynamically distributes.Specifically, it is as follows：

1st, network model and hypothesis

As shown in Figure 1, it is assumed that the infrastructure networks that master network is made up of multiple primary users (PUs) and a base station (BS) Network, PUs is T to the time slot that each primary user distributes with TDMA modes and base station communication, base station, it is assumed that the frequency spectrum of each primary user Bandwidth is W.Cognition network is that cognitive user is set up by N to send and reception pairThe distributed network of composition.It is main Frequency spectrum share uses two benches FDMA pass-through mode between secondary user：The frequency spectrum of oneself is divided into τ W and (1- τ) W two by primary user Mutually orthogonal sub-band, τ W frequency ranges are used for the data transfer for completing primary user, and (1- τ) W frequency allocations send user to cognitive Send the data of oneself.Cognition sends user and takes amplification forwarding (AF, Amplifier-and-forward) mode to help primary Family forward data, τ W frequency ranges preceding 0.5T time slots primary user to be selected as relaying cognitive user and base station broadcast oneself number According to rear 0.5T time slots primary user sends the data of primary user with relaying cognitive user to base station.Assuming that in each time slot T channel Information invariability.PU and BS, ST_iThe channel gain G of link between BS_PBWithEstimate by BS, PU and ST_iBetween link channel GainBy ST_iEstimation, ST_iWith SR_iBetween link channel gainBy SR_iEstimation.Assuming that there is a public control in network Channel, the channel gain of each link is sent to PU and ST in PU, gambling process by common signal channel_iBetween feedback of the information also by The channel transfer.Interchannel noise is white Gaussian noise, and noise power is δ²。

2nd, targeted yield function

As shown in Figure 2,3, set up using PU as leader, multiple noncooperative cognitive user STs that send are the two of subordinate Level Stark Burger betting model.PU strategy is the great transimission power of selection and how to distribute the frequency spectrum resource of oneself to make oneself Own network utility is maximized, each ST_iStrategy be that the great power of selection helps PU transmission data so that the network effect of oneself With reaching maximum.

1) PU utility function is defined：

Wherein, U_PD,U_PCIt is primary user PU respectively in the effectiveness for direct transferring with being obtained under cooperation mode, R_PDIt is gulping down of direct transferring of PU The amount of telling, E_PDIt is that PU direct transfers the energy of consumption, The handling capacity that cooperation mode is obtained, P are selected for PU_PCFor the transimission power under PU cooperation modes,For ST_iHelp PU forwarding numbers According to transimission power, E_PCThe energy of consumption, I (E are transmitted under cooperation mode for PU_P0) be PU existing energy level to PU transmit Consumed energy take notice of degree function be PU cooperation modes obtain handling capacity, S for participate in cooperation STs set.E_PC=τ WTP_PCThe energy of consumption is transmitted under cooperation mode for PU.I(E_P0) be PU existing energy level to PU transmit consumed energy exist Meaning degree function

Wherein, E_P0For PU existing energy,For the critical value of the existing energy levels of PU.

PU strategy is the great transmit power of selection and how to distribute the frequency spectrum resource of oneself and make oneself network utility most Bigization, i.e.,

s.t.0<τ<1

WhereinThe minimum throughout for wishing to reach for PU,For PU maximum transmission power.

2) defined cognitive user ST_iUtility function be：

WhereinFor ST_iThe handling capacity of acquisition,For ST_iDistribution The spectral bandwidth arrived,For ST_iTransmit the transmit power of oneself data.For ST_iFor PU transmit data consumed energy unit into This,For ST_iHelp the energy of PU forwarding data consumption.

ST_iStrategy be that the great power of selection helps PU to transmit data so that the network utility of oneself reaches maximum, i.e.,：

3rd, game theory analysis

1) it is cognitive to send user's optimal policy

(3) formula is to P first_SICDerivation is obtained

When being optimal solution, (5) formula is equal to 0, obtains

Wherein N_SCTo participate in the STs numbers of cooperation.ST_iWhether participate in The condition of cooperation is：

2) primary user's optimal policy

1. primary user's optimal policy under the mode that direct transfers

(1) formula is to P first_PDDerivation is obtained：

When being optimal solution, (8) formula is equal to 0, obtains：

2. primary user's optimal policy under cooperation mode

(1) formula is to P first_PCDerivation is obtained：

WhereinWhen being optimal solution, (10) formula is equal to 0, obtains Arrive：

WhereinRepresent I (E_p0(10) are equal to 0 solution during) ≠ 0.(6) and (11) are substituted into U_PC, U_PCτ derivations can be obtained

WhereinWhen (12) are equal to 0, τ obtains optimal τ^*。

The above embodiment is interpreted as being merely to illustrate the present invention rather than limited the scope of the invention. After the content for the record for having read the present invention, technical staff can make various changes or modifications to the present invention, these equivalent changes Change and modification equally falls into the inventive method claim limited range.

Claims (2)

1. the frequency spectrum sharing method based on Stark Burger game in cooperative cognitive wireless network, the cooperative cognitive wireless network Master network be the infrastructure network that is made up of multiple primary user PU and a base station BS, primary user PU is accessed with time division multiple acess Mode communicates with base station BS, and base station BS is T to the time slot that each primary user PU is distributed, it is assumed that the spectral bandwidth of each primary user is equal For W, cognition network includes N number of cognitive transmission user ST_i(i=1,2 ..., N) and cognitive reception user SR_iRight, its feature exists In comprising the following steps：

101st, by the frequency spectrum share between primary user PU and secondary user using two benches FDMA cooperation pass-through modes, primary user PU will The frequency spectrum of oneself is divided into τ W and two mutually orthogonal sub-bands of (1- τ) W；

102nd, base station BS estimates the channel gain G of link between primary user PU and base station BS respectively_PBAnd cognitive transmission user ST_iWith base Stand the channel gain of link between BSCognition sends user ST_iEstimate that primary user PU sends user ST with cognitive_iBetween link Channel gainCognition receives user SR_iEstimation is cognitive to send user ST_iUser SR is received with cognition_iBetween link channel increase BenefitAnd by the channel gain G of estimation_PB, channel gainChannel gainAnd channel gainIt is transmitted to primary user PU；

103rd, set up using primary user PU as leader, multiple noncooperative cognitive user STs that send are this tower of the two-stage of subordinate Gram Burger betting model, initially sets up primary user PU utility functionIts In, U_PD,U_PCIt is primary user PU respectively in the effectiveness for direct transferring with being obtained under cooperation mode, R_PDIt is the handling capacity that PU direct transfers, E_PDIt is PU Direct transfer the energy of consumption, R_PCFor the handling capacity under PU cooperation modes, E_PCThe energy of consumption, I are transmitted under cooperation mode for PU (E_P0) it is that PU existing energy level transmits consumed energy to PU and takes notice of degree function, E_P0For PU existing energy；Then set up Cognition sends user ST_iUtility function be：WhereinFor ST_iThe handling capacity of acquisition,For ST_iThe unit cost of data consumed energy is transmitted for PU,For ST_iThe energy of PU forwarding data consumption is helped, using Stark Burger game method carries out game to (1) and (2), and PU estimates optimal frequency spectrum distribution coefficient τ^*With optimal transmission powerIf τ^*=1, primary user broadcasts to all cognitive users and does not lease the information of frequency spectrum, conversely, primary user is by τ^*,It is broadcast to all Cognition sends user, and primary user's selection can make the maximized cognitive user's collection that sends of its utility function as relay node user, Primary user feeds back a reference information to all relay node users, and each selected cognitive transmission user is according to reference information Calculate the transimission power for oneself being used for cooperating

104th, when primary user selects the mode that direct transfers, primary user sends use using the whole frequency spectrum resources transmission data of oneself, cognition Family does not help primary user to transmit data, while cognitive send user because frequency spectrum is arrived in failed lease, cannot transmit oneself yet Data；If primary user selects cooperation mode, primary user sends user in first sub-band i.e. with a width of τ with cognitive^*W The data of upper cooperation transmission primary user, each cognition for being selected as relaying sends user in second sub-band i.e. with a width of (1- τ^*) W is upper to transmit the data of oneself in the way of OFDM in the frequency range for distributing to it.

2. the frequency spectrum sharing method based on Stark Burger game in cooperative cognitive wireless network according to claim 1, It is characterized in that：The transmission consumed energy takes notice of degree function I (E_P0) expression formula be：

$I\left(E_{P0}\right)=\left\{\begin{array}{cc}\frac{{\exp }^{-\left(E_P^{th}-E_{P0}\right)}}{10}& 0<E_{P0}<E_P^{th}\\ 0& E_{P0}\&GreaterEqual;E_P^{th}\end{array}\right.$

Wherein, E_P0For PU existing energy,For the critical value of the existing energy levels of PU.