CN102833866A - Resource allocation method for cooperation relay orthogonal frequency division multiple access system - Google Patents

Abstract

The invention discloses a resource allocation method for a cooperation relay orthogonal frequency division multiple access system. The method comprises the following steps of adding constraints of different lowest velocity demands of various users when establishing an optimal resource allocation module, introducing a user velocity weighting factor in sub-carrier allocation and relay selection processes, and performing sub-carrier allocation and relay selection according to the principle that the user has the priority in sub-carrier and relay selection if the velocity weighting factor of the user is large, thus, the lowest velocity demand of various users can be ensured well. As a simple equal power allocation method is adopted in the process of simplifying the optimal resource allocation module, the calculation complexity is effectively reduced; the rest of sub-carriers are allocated to various users according to the largest transient velocity, thus, the total velocity of the system can be maximized; and the sub-carriers can be adaptively allocated to various users according to the largest user velocity weighting factor and transient velocity, thus, the change of the wireless communication environment can be adapted well.

Description

A kind of resource allocation methods of cooperating relay orthogonal frequency division multiple access system

Technical field

The present invention relates to a kind of resource allocation methods of wireless communication system; Especially relate to a kind of cooperating relay OFDM and insert (Orthogonal Frequency Division Multiplex Access; OFDMA) resource allocation methods of system; (Quality of Service QoS) guarantees this resource allocation methods based on service quality.

Background technology

Pilosity send multiple receive antenna (Multiple-Input Multiple-Out-put; MIMO) technology is the major technological breakthrough of wireless communication field; It is through install many antennas at receiving terminal and transmitting terminal simultaneously; Form the mimo channel structure,, thereby improved the capacity and the reliability of wireless communication system exponentially because it has made full use of the spatial domain resource.But in practical application; Owing to receive the restriction of portable terminal size, power supply and hardware system complexity; Many antennas operated by rotary motion of MIMO technology and be difficult in many antennas are installed on the portable terminal, so the MIMO technology is difficult to be applied directly in the practical wireless communication systems in the base station.Yet the cooperating relay communication technology is a kind of brand-new communication pattern; It is through internodal transmission of assisting the information of completion mutually; Between source node and destination node, set up many virtual decline links, make single antenna mobile terminal in multi-user environment, can share the antenna at other terminal, thereby obtain space diversity gain; Significantly enlarge the coverage of network, improve the transmission performance of system.The cooperating relay communication technology has merged the technical advantage of diversity scheme and relay transmission, and the practicability technological for MIMO provides a new approach, has caused the extensive concern of radio communication circle.

OFDM (Orthogonal Frequency Division Multiplexing; OFDM) whole frequency band is divided into many subcarriers mutually orthogonal and that be overlapping; Avoided traditional FDM (Frequency-division multiplexing; Frequency division multiplex) interval of the protection in the multicarrier modulation system, thus the availability of frequency spectrum improved greatly; And it is through frequency selective fading channels being converted into some flat fading subchannels, thereby can resist the frequency selective fading in the wireless mobile environment effectively.Because the subcarrier plyability takies frequency spectrum, OFDM can provide the higher availability of frequency spectrum and the rate of information throughput, therefore is highly suitable for the high-speed transfer under the WiMAX channel.Through distributing different subcarriers to different user, (Orthogonal Frequency Division Multiple Access OFDMA) provides natural multi-access mode in the OFDM access.Because different user takies different subcarriers, satisfy the orthogonality of frequency resource allocation between the user in sub-district, almost there is not the influence of multiple access interference between each user.Because the independence of channel fading between the user, the multi-user diversity gain that can utilize the joint subcarrier distribution to bring improves performance, reaches service quality (QoS) requirement.Along with OFDM inserts the increasingly mature of (OFDMA) technical research; Cellular transmission system in conjunction with cooperating relay can obtain higher peak data rate, the availability of frequency spectrum; And better community marginal user performance, therefore carry out OFDMA research technological and that the cooperating relay technology combines and become the focus that numerous researchers pay close attention to.And contain the research focus that resource allocation problem in the OFDMA system of cooperating relay also becomes present stage gradually.

The resource allocation problem that contains the OFDMA system of cooperating relay is the combined optimization problem of a sub-carrier, power, bit, Adaptive Modulation and relay selection, and this is a NP (Non-deterministic Polynomial, a non-multinomial algorithm) problem.Traditional solution is to distribute fixing subcarrier and relaying for each user; Carry out power, Bit Allocation in Discrete and Adaptive Modulation based on the allocative decision of subcarrier and relaying then; Because this solution is distributed fixing subcarrier and relaying; Therefore can not well adapt to the variation of wireless communications environment, like barrier, environment temperature; In addition, in wireless communication system, also need possess the ability that guarantees that user's minimum quality of service (QoS) requires, simultaneously in some occasion, wireless communication system possibly also can propose high requirement to user fairness.

Summary of the invention

Technical problem to be solved by this invention provides a kind of resource allocation methods of cooperating relay orthogonal frequency division multiple access system, and its computation complexity is low, and the demand that can guarantee QoS of customer, and can be good at adapting to the variation of wireless communications environment.

The present invention solves the problems of the technologies described above the technical scheme that is adopted: a kind of resource allocation methods of cooperating relay orthogonal frequency division multiple access system is characterized in that may further comprise the steps:

1. according to the minimum quality of service requirement of different user in the cooperating relay OFDMA system, set up optimize allocation of resources

$\max \underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a_{k,j,n}}^{\′}{R}_{k,j,n}$

The constraints that satisfies:

A1: $\underset{j=1}{\overset{M+K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{p}_{S,j,n}\≤P_T$

Model: A2:

wherein; Max () is for getting max function, and K representes cooperating relay

A3:a _k，j,n'∈{0,1}

A4: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{a_{k,j,n}}^{\′}=1$

A5: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a_{k,j,n}}^{\′}{R}_{k,j,n}\≥Q_j$

Relaying number in the OFDMA system, K>=1, M representes the user's number in the cooperating relay OFDMA system, M>1, N representes the subcarrier number in the cooperating relay OFDMA system, N>1; a _{K, j, n}' the integer factor before expression is lax, whether it is used to characterize n number of sub-carrier and k relaying by j CU, P _TThe total emission power at place, expression base station, P _{K, T}The transmitting power of representing k relaying place, Q _jThe minimum speed limit value of representing j user; Constraints A1 representes the total emission power constraint at base station place, in constraints A1, and when 1≤j≤M, p _{S, j, n}Expression base station and the transmitted power of j this communication link of user on the n number of sub-carrier, when M+1≤j≤M+K, p _{S, j, n}Expression base station and the transmitted power of k this communication link of relaying on the n number of sub-carrier; Constraints A2 representes the transmitted power constraint at each relaying place; Whether constraints A3 is used to characterize n number of sub-carrier and k relaying by j CU, a _{K, j, n}N number of sub-carrier and k relaying are represented not by j CU in '=0, a _{K, j, n}'=1 expression n number of sub-carrier and k relaying are by j CU; Constraints A4 representes that a number of sub-carrier can only be taken by a user and corresponding relay at most; Constraints A5 representes the minimum quality of service requirement of different user, and it is described as the minimum speed limit demand of different user; R _{K, j, n}Represent j user through k relaying on the n number of sub-carrier momentary rate and $R_{k,j,n}=\frac{1}{2}\min \{\log 2(1+p_{S,M+k,n}{H}_{S,M+k,n}),\log 2(1+p_{S,j,n}{H}_{S,j,n}+p_{k,j,n}{H}_{k,j,n})\},$ Min () is for getting minimum value function, p _{S, M+k, n}Expression base station and the transmitted power of k this communication link of relaying on the n number of sub-carrier, H _{S, M+k, n}Expression base station and the channel gain of k this communication link of relaying on the n number of sub-carrier, p _{S, j, n}Expression base station and the transmitted power of j this communication link of user on the n number of sub-carrier, H _{S, j, n}Expression base station and the channel gain of j this communication link of user on the n number of sub-carrier, p _{K, j, n}Represent that j user is through the transmitted power of k relaying on the n number of sub-carrier, H _{K, j, n}Represent that j user is through the channel gain of k relaying on the n number of sub-carrier;

2. with the lax preceding integer factor a in the above-mentioned optimize allocation of resources model _{K, j, n}' lax be a variable between [0,1], be designated as a _{K, j, n}, and the power that adopts the constant power distribution method to equate for each subcarrier allocation, the optimization that obtains simplifying

$\underset{a_{k,j,n}}{\max }\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}$

The constraints that satisfies:

Resource allocator model: B1:a _{K, j, n}∈ [0,1], wherein,

Expression is with a _{K, j, n}For optimization variable

B2: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{a}_{k,j,n\≤}1$

B3: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a_{k,j,n}R}_{k,j,n}\≥Q_j$

Get max function, a _{K, j, n}Be used to characterize j user and corresponding k the proportional numbers that relaying takies on the n number of sub-carrier; Constraints B1 representes a _{K, j, n}Value be [0,1] any numerical value in interval; Constraints B2 representes that a number of sub-carrier can be taken by a plurality of users and corresponding relay; Constraints B3 representes the minimum speed limit demand of different user;

3. construct a Lagrange's equation relevant, be expressed as with the optimize allocation of resources model of above-mentioned simplification: $\begin{array}{c}L(a_{k,j,n},{\mathrm{\β}}_n,{\mathrm{\δ}}_{k,j,n},{\mathrm{\μ}}_j)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}+\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\β}}_n(1-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n})\\ +\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\δ}}_{k,j,n}{a}_{k,j,n}+\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{\mathrm{\μ}}_j(\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}-Q_j)\end{array},$ Wherein, β _nExpression

Lagrangian, δ _{K, j, n}Expression a _{K, j, n}Lagrangian, μ _jExpression $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}-Q_j$ Lagrangian;

4. will $\begin{array}{c}L(a_{k,j,n},{\mathrm{\β}}_n,{\mathrm{\δ}}_{k,j,n},{\mathrm{\μ}}_j)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}+\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\β}}_n(1-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n})\\ +\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\δ}}_{k,j,n}{a}_{k,j,n}+\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{\mathrm{\μ}}_j(\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}-Q_j)\end{array}$ To a _{K, j, n}Carry out differentiate, obtain corresponding single order KKT necessary condition, be expressed as: $\begin{array}{c}C1:R_{k,j,n}-{\mathrm{\β}}_n+{\mathrm{\δ}}_{k,j,n}+{\mathrm{\μ}}_j{R}_{k,j,n}=0\\ C2:{\mathrm{\δ}}_{k,j,n}{a}_{k,j,n}=0\\ C3:{\mathrm{\μ}}_j(Q_j-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n})=0\end{array},$ Here, 1≤k≤K, 1≤j≤M, 1≤n≤N;

5. turn to only relaying of subcarrier and selection that each user distributes an optimum according to the momentary rate maximum, according to single order KKT necessary condition remaining subcarrier is divided to be equipped with then to guarantee that each user can both satisfy the minimum speed limit demand.

Described step turns to subcarrier that each user distributes an optimum and selects an only relaying according to the momentary rate maximum in 5., according to single order KKT necessary condition to the detailed process that remaining subcarrier distributes is then:

5.-1, initialization: make sub-carrier set be combined into Ω _N, user's set is Ω _M, relay collection is Ω _KMaking the total emission power at place, base station is P _T, the performance number size of distributing on each subcarrier when then adopting the constant power distribution method does Wherein, N representes the subcarrier number in the cooperating relay OFDMA system, and M representes the user's number in the cooperating relay OFDMA system, and K representes the relaying number in the wireless cooperation relaying OFDMA system;

5.-2, turning to each user according to the momentary rate maximum distributes the subcarrier of an optimum and selects only relaying a: a1, calculates each user and obtain maximum subcarrier of momentary rate and corresponding relaying from the base station; And the subcarrier that momentary rate is maximum gives corresponding user as the subcarrier allocation of optimum, again from subcarrier set Ω _NThe optimum subcarrier of middle deletion supposes that j user obtains the maximum subcarrier of momentary rate from the base station be n ^*Number of sub-carrier, corresponding relaying are k ^*Individual relaying then has (k ^*, n ^*)=arg maxR _{K, j, n}, then with n ^*Number of sub-carrier is given j user as the subcarrier allocation of optimum, and with corresponding k ^*Individual relaying is as only relaying, again with n ^*Number of sub-carrier is gathered Ω from subcarrier _NMiddle deletion, wherein, 1≤n ^*≤N, 1≤k ^*≤K, arg () is for getting parametric function, and max () is for getting max function, (k ^*, n ^*)=arg max R _{K, j, n}Expression is found out j user and is obtained maximum subcarrier of momentary rate and corresponding relaying from the base station, is respectively n ^*Number of sub-carrier and k ^*Individual relaying, R _{K, j, n}J user is through the momentary rate of k relaying on the n number of sub-carrier in the expression expression; A2, then order is used to characterize j user and corresponding k ^*Individual relaying is at n ^*The proportional numbers that takies on the number of sub-carrier

And upgrade j user's actual speed rate R _j,

Wherein,

In "=" be assignment, the R on the left side _jJ user's after expression is upgraded actual speed rate, the R on the right _jJ user's before expression is upgraded actual speed rate, R _jInitial value be 0,

Represent that j user is through k ^*Individual relaying is at n ^*Momentary rate on the number of sub-carrier, $R_{k^{*},j,n^{*}}=\frac{1}{2}\min \{\log 2(1+p_{S,M+k^{*},n^{*}}{H}_{S,M+k^{*},n^{*}}),\log 2(1+p_{S,j,n^{*}}{H}_{S,j,n^{*}}+p_{k^{*},j,n^{*}}{H}_{k^{*},j,n^{*}})\},$ $p_{S,M+k^{*},n^{*}}$ Expression base station and k ^*This communication link of individual relaying is at n ^*Transmitted power on the number of sub-carrier,

Expression base station and k ^*This communication link of individual relaying is at n ^*Channel gain on the number of sub-carrier,

Expression base station and j this communication link of user are at n ^*Transmitted power on the number of sub-carrier,

Expression base station and j this communication link of user are at n ^*Channel gain on the number of sub-carrier,

Represent that j user is through k ^*Individual relaying is at n ^*Transmitted power on the number of sub-carrier, the size of its value does

Represent that j user is through k ^*Individual relaying is at n ^*Channel gain on the number of sub-carrier;

5.-3, remaining subcarrier is distributed: b1, obtain δ according to single order KKT necessary condition C1 _{K, j, n}=β _n-(1+ μ _j) R _{K, j, n}, obtain according to single order KKT necessary condition C2 then Obtain according to single order KKT necessary condition C3 again

B2, according to δ _{K, j, n}=β _n-(1+ μ _j) R _{K, j, n}With

Obtain β _n=(1+ μ _j) R _{K, j, n}, and make w _jThe speed weighting factor of representing j user, w _j=Q _j-R _j, then will

Be reduced to Wherein, R _jThe actual speed rate of representing j user; B3, according to β _n=(1+ μ _j) R _{K, j, n}With

Confirm to work as μ _jThe n number of sub-carrier is distributed to j at=0 o'clock ^*Individual user and corresponding k ^*Individual relaying makes Work as μ _j>The n number of sub-carrier distributed to the maximum user of momentary rate and corresponding relay with the total speed of maximization system at 0 o'clock, be respectively j ^*Individual user and k ^*Individual relaying, wherein,

Represent j ^*Individual user's speed weighting factor, wherein, 1≤j ^*≤M; B4, find out the minimum speed limit that will reach and the maximum user of actual speed rate difference, suppose that the user who finds out is j ^*Individual user then has j ^*=arg max w _j, wherein, 1≤j ^*≤M, arg max w _jThe user of institute's minimum speed limit that will reach and actual speed rate difference maximum is found out in expression; The j that b5, judgement are found out ^*Individual user's speed weighting factor

Whether greater than 0, if, show that then each with unmet minimum speed limit demand per family, continues execution in step b6 then, otherwise, show that each with having satisfied the minimum speed limit demand per family, continues execution in step b7 then; B6, find out and satisfy condition

Subcarrier and corresponding relaying, suppose that the subcarrier of finding out is n ^*Number of sub-carrier, and corresponding relaying is k ^*Individual relaying is then with n ^*Number of sub-carrier is distributed to j ^*Individual user, wherein,

J is found out in expression ^*Individual user obtains maximum subcarrier of momentary rate and corresponding relaying from the base station, be respectively n ^*Number of sub-carrier and k ^*Individual relaying,

Represent j ^*Individual user is through the momentary rate of k relaying on the n number of sub-carrier; Then with n ^*Number of sub-carrier is gathered Ω from subcarrier _NMiddle deletion; Then order is used to characterize j ^*Individual user and corresponding k ^*Individual relaying is at n ^*The proportional numbers that takies on the number of sub-carrier

And upgrade j ^*Individual user's actual speed rate

Wherein,

In "=" be assignment, the left side

J after expression is upgraded ^*Individual user's actual speed rate, the right

J before expression is upgraded ^*Individual user's actual speed rate,

Initial value be 0,

Represent j ^*Individual user is through k ^*Individual relaying is at n ^*Momentary rate on the number of sub-carrier, $R_{k^{*},j^{*},n^{*}}=\frac{1}{2}\mathrm{Min}\{\mathrm{Log}2(1+p_{S,M+k^{*},n^{*}}{H}_{S,M+k^{*},n^{*}}),\mathrm{Log}2(1+p_{S,j^{*},n^{*}}{H}_{S,j^{*},n^{*}}+p_{k^{*},j^{*},n^{*}}{H}_{k^{*},j^{*},n^{*}})\},$

Expression base station and k ^*This communication link of individual relaying is at n ^*Transmitted power on the number of sub-carrier,

Expression base station and k ^*This communication link of individual relaying is at n ^*Channel gain on the number of sub-carrier,

Expression base station and j ^*This communication link of individual user is at n ^*Transmitted power on the number of sub-carrier,

Expression base station and j ^*This communication link of individual user is at n ^*Channel gain on the number of sub-carrier,

Represent j ^*Individual user is through k ^*Individual relaying is at n ^*Transmitted power on the number of sub-carrier,

Represent j ^*Individual user is through k ^*Individual relaying is at n ^*Channel gain on the number of sub-carrier; Continue execution in step b8 again; B7, find out momentary rate maximum user and corresponding relaying, suppose that the n number of sub-carrier is remaining subcarrier, and to be assumed to be the maximum user of its momentary rate of finding out be j for remaining subcarrier ^*Individual user, and corresponding relaying is k ^*Individual relaying then has (k ^*, j ^*)=arg maxR _{K, j, n '}, wherein, (k ^*, j ^*)=arg maxR _{K, j, n '}Be expressed as the n number of sub-carrier and find out maximum user of momentary rate and corresponding relaying, be respectively j ^*Individual user and k ^*Individual relaying; Then the n number of sub-carrier is gathered Ω from subcarrier _NMiddle deletion; Then order is used to characterize j ^*Individual user and corresponding k ^*The proportional numbers that individual relaying takies on the n number of sub-carrier

And upgrade j ^*Individual user's actual speed rate

Wherein,

In "=" be assignment, the left side

J after expression is upgraded ^*Individual user's actual speed rate, the right

J before expression is upgraded ^*Individual user's actual speed rate,

Initial value be 0,

Represent j ^*Individual user is through k ^*The momentary rate of individual relaying on the n number of sub-carrier, $R_{k^{*},j^{*},n}=\frac{1}{2}\mathrm{Min}\{\mathrm{Log}2(1+p_{S,M+k^{*},n}{H}_{S,M+k^{*},n}),\mathrm{Log}2(1+p_{S,j^{*},n}{H}_{S,j^{*},n}+p_{k^{*},j^{*},n}{H}_{k^{*},j^{*},n})\},$ $p_{S,M+k^{*},n}$ Expression base station and k ^*The transmitted power of this communication link of individual relaying on the n number of sub-carrier,

Expression base station and k ^*The channel gain of this communication link of individual relaying on the n number of sub-carrier, Expression base station and j ^*The transmitted power of this communication link of individual user on the n number of sub-carrier, Expression base station and j ^*The channel gain of this communication link of individual user on the n number of sub-carrier,

Represent j ^*Individual user is through k ^*The transmitted power of individual relaying on the n number of sub-carrier,

Represent j ^*Individual user is through k ^*The channel gain of individual relaying on the n number of sub-carrier; Continue execution in step b8 again; B8, judgement subcarrier set Ω _NWhether be empty set, if, show that then subcarrier allocation and relay selection finish, otherwise, return step b4 and continue to carry out.

The described step 1. value of middle K is 3,4 or 5, and the value of M is 6,8,10 or 12, and the value of N is 128,256,512 or 1024.

Compared with prior art, the invention has the advantages that:

1) the inventive method is through having added the constraints of the different minimum speed limit demands of each user when setting up the optimize allocation of resources model; In subcarrier allocation and relay selection process, introduced the user rate weighting factor then; The user big more according to the speed weighting factor; This criterion of priority that has chooser carrier wave and relaying is more carried out subcarrier allocation and relay selection; Can make the inventive method can guarantee each user's minimum speed limit demand well like this, promptly guarantee each quality of services for users demand.

2) the inventive method has adopted simple constant power distribution method in the process of simplifying the optimize allocation of resources model, effectively reduces computation complexity.

3) the inventive method is given each user with remaining subcarrier according to the momentary rate maximum allocated, can maximize the total speed of system.

4) the inventive method is given each user with subcarrier allocation adaptively according to user rate weighting factor and momentary rate maximum, is a kind of dynamic resource allocation method, thereby can be good at adapting to the variation of wireless communications environment.

Description of drawings

Fig. 1 is the single cellular downlink model of communication systems of many cooperating relay;

Fig. 2 obtains the comparison that speed and minimum speed limit require for the user under the different resource distribution method;

Fig. 3 is the total speed of system under the different signal to noise ratios of different resource distribution method.

Embodiment

Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.

The resource allocation methods of a kind of cooperating relay orthogonal frequency division multiple access system that the present invention proposes, the single cellular downlink model of communication system of its applied many cooperating relay is as shown in Figure 1.For guaranteeing that each user in the single cellular downlink communication system of many cooperating relay can both receive the signal that sends from the base station, choose semiduplex cooperation transmission mode, at first time slot, information is sent to relaying and user in the base station; At second time slot; Relaying is transmitted to the user with the information decoding that receives; Supposing has a base station BS that is positioned at the center in the single cellular downlink communication system of many cooperating relay, and K relay RS and M user are arranged, and the total available bandwidth of system is B; And whole frequency is divided into N orthogonal sub-carriers, and the total emission power at place, base station is P _T, with seasonal N ₀Expression white Gaussian noise one-sided power spectrum density.

Resource allocation methods of the present invention specifically may further comprise the steps:

1. according to the minimum quality of service requirement of different user in the cooperating relay OFDMA system, set up optimize allocation of resources

$\max \underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a_{k,j,n}}^{\′}{R}_{k,j,n}$

The constraints that satisfies:

A1: $\underset{j=1}{\overset{M+K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{p}_{S,j,n}\≤P_T$

Model: A2:

wherein; Max () is for getting max function, and K representes cooperating relay

A3:a _k,j，n'∈{0,1}

A4: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{a_{k,j,n}}^{\′}=1$

A5: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a_{k,j,n}}^{\′}{R}_{k,j,n}\≥Q_j$

Relaying number in the OFDMA system, K>=1, M representes the user's number in the cooperating relay OFDMA system, M>1, N representes the subcarrier number in the cooperating relay OFDMA system, N>1, in the simulation process of reality, the value of K is desirable as 3,4,5, and the value of M is desirable as 6,8,10,12, and the value of N is desirable as 128,256,512,1024, and these values are more common; a _{K, j, n}' the integer factor before expression is lax, whether it is used to characterize n number of sub-carrier and k relaying by j CU, P _TThe total emission power at place, expression base station, P _{K, T}The transmitting power of representing k relaying place, Q _jThe minimum speed limit value of representing j user; Constraints A1 representes the total emission power constraint at base station place, in constraints A1, and when 1≤j≤M, p _{S, j, n}Expression base station and the transmitted power of j this communication link of user on the n number of sub-carrier, when M+1≤j≤M+K, p _{S, j, n}Expression base station and the transmitted power of k this communication link of relaying on the n number of sub-carrier; Constraints A2 representes the transmitted power constraint at each relaying place; Whether constraints A3 is used to characterize n number of sub-carrier and k relaying by j CU, a _{K, j, n}N number of sub-carrier and k relaying are represented not by j CU in '=0, a _{K, j, n}'=1 expression n number of sub-carrier and k relaying are by j CU; Constraints A4 representes that a number of sub-carrier can only be taken by a user and corresponding relay at most; Constraints A5 representes the minimum quality of service requirement of different user, and it is described as the minimum speed limit demand of different user; R _{K, j, n}Represent j user through k relaying on the n number of sub-carrier momentary rate and $R_{k,j,n}=\frac{1}{2}\min \{\log 2(1+p_{S,M+k,n}{H}_{S,M+k,n}),\log 2(1+p_{S,j,n}{H}_{S,j,n}+p_{k,j,n}{H}_{k,j,n})\},$ Min () is for getting minimum value function, p _{S, M+k, n}Expression base station and the transmitted power of k this communication link of relaying on the n number of sub-carrier, H _{S, M+k, n}Expression base station and the channel gain of k this communication link of relaying on the n number of sub-carrier, p _{S, j, n}Expression base station and the transmitted power of j this communication link of user on the n number of sub-carrier, H _{S, j, n}Expression base station and the channel gain of j this communication link of user on the n number of sub-carrier, p _{K, j, n}Represent that j user is through the transmitted power of k relaying on the n number of sub-carrier, H _{K, j, n}Represent that j user is through the channel gain of k relaying on the n number of sub-carrier.

2. with the lax preceding integer factor a in the above-mentioned optimize allocation of resources model _{K, j, n}' lax be a variable between [0,1], be designated as a _{K, j, n}, and the power that adopts the constant power distribution method to equate for each subcarrier allocation, the optimization that obtains simplifying

$\underset{a_{k,j,n}}{\max }\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}$

The constraints that satisfies:

Resource allocator model: B1:a _{K, jn}∈ [0,1], wherein,

Expression is with a _{K, j, n}For optimization variable

B2: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{a}_{k,j,n\≤}1$

B3: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a_{k,j,n}R}_{k,j,n}\≥Q_j$

Get max function, a _{K, j, n}Be used to characterize j user and corresponding k the proportional numbers that relaying takies on the n number of sub-carrier; Constraints B1 representes a _{K, j, n}Value be [0,1] any numerical value in interval; Constraints B2 representes that a number of sub-carrier can be taken by a plurality of users and corresponding relay; Constraints B3 representes the minimum speed limit demand of different user.

3. construct a Lagrange's equation relevant, be expressed as with the optimize allocation of resources model of above-mentioned simplification: $\begin{array}{c}L(a_{k,j,n},{\mathrm{\β}}_n,{\mathrm{\δ}}_{k,j,n},{\mathrm{\μ}}_j)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}+\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\β}}_n(1-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n})\\ +\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\δ}}_{k,j,n}{a}_{k,j,n}+\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{\mathrm{\μ}}_j(\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}-Q_j)\end{array},$ Wherein, β _nExpression Lagrangian, δ _{K, j, n}Expression a _{K, j, n}Lagrangian, μ _jExpression $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}-Q_j$ Lagrangian.

4. will $\begin{array}{c}L(a_{k,j,n},{\mathrm{\β}}_n,{\mathrm{\δ}}_{k,j,n},{\mathrm{\μ}}_j)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}+\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\β}}_n(1-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n})\\ +\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\δ}}_{k,j,n}{a}_{k,j,n}+\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{\mathrm{\μ}}_j(\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}-Q_j)\end{array}$ To a _{K, j, n}Carry out differentiate, obtain corresponding single order KKT necessary condition, be expressed as: $\begin{array}{c}C1:R_{k,j,n}-{\mathrm{\β}}_n+{\mathrm{\δ}}_{k,j,n}+{\mathrm{\μ}}_j{R}_{k,j,n}=0\\ C2:{\mathrm{\δ}}_{k,j,n}{a}_{k,j,n}=0\\ C3:{\mathrm{\μ}}_j(Q_j-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n})=0\end{array},$ Here, 1≤k≤K, 1≤j≤M, 1≤n≤N.

5. turn to only relaying of subcarrier and selection that each user distributes an optimum according to the momentary rate maximum, according to single order KKT necessary condition remaining subcarrier is divided to be equipped with then to guarantee that each user can both satisfy the minimum speed limit demand.

In this specific embodiment, step turns to subcarrier that each user distributes an optimum and selects an only relaying according to the momentary rate maximum in 5., according to single order KKT necessary condition to the detailed process that remaining subcarrier distributes is then:

5.-1, initialization: make sub-carrier set be combined into Ω _N, user's set is Ω _M, relay collection is Ω _KMaking the total emission power at place, base station is P _T, the performance number size of distributing on each subcarrier when then adopting the constant power distribution method does

Wherein, N representes the subcarrier number in the cooperating relay OFDMA system, and M representes the user's number in the cooperating relay OFDMA system, and K representes the relaying number in the wireless cooperation relaying OFDMA system.

5.-2, turning to each user according to the momentary rate maximum distributes the subcarrier of an optimum and selects only relaying a: a1, calculates each user and obtain maximum subcarrier of momentary rate and corresponding relaying from the base station; And the subcarrier that momentary rate is maximum gives corresponding user as the subcarrier allocation of optimum, again from subcarrier set Ω _NThe optimum subcarrier of middle deletion supposes that j user obtains the maximum subcarrier of momentary rate from the base station be n ^*Number of sub-carrier, corresponding relaying are k ^*Individual relaying then has (k ^*, n ^*)=arg maxR _{K, j, n}, then with n ^*Number of sub-carrier is given j user as the subcarrier allocation of optimum, and with corresponding k ^*Individual relaying is as only relaying, again with n ^*Number of sub-carrier is gathered Ω from subcarrier _NMiddle deletion, wherein, 1≤n ^*≤N, 1≤k ^*≤K, arg () is for getting parametric function, and max () is for getting max function, (k ^*, n ^*)=argmaxR _{K, j, n}Expression is found out j user and is obtained maximum subcarrier of momentary rate and corresponding relaying from the base station, is respectively n ^*Number of sub-carrier and k ^*Individual relaying, R _{K, j, n}Represent that j user is through the momentary rate of k relaying on the n number of sub-carrier; A2, then order is used to characterize j user and corresponding k ^*Individual relaying is at n ^*The proportional numbers that takies on the number of sub-carrier

And upgrade j user's actual speed rate R _j,

Wherein,

In "=" be assignment, the R on the left side _jJ user's after expression is upgraded actual speed rate, the R on the right _jJ user's before expression is upgraded actual speed rate, R _jInitial value be 0,

Represent that j user is through k ^*Individual relaying is at n ^*Momentary rate on the number of sub-carrier, $R_{k^{*},j,n^{*}}=\frac{1}{2}\min \{\log 2(1+p_{S,M+k^{*},n^{*}}{H}_{S,M+k^{*},n^{*}}),\log 2(1+p_{S,j,n^{*}}{H}_{S,j,n^{*}}+p_{k^{*},j,n^{*}}{H}_{k^{*},j,n^{*}})\},$ $p_{S,M+k^{*},n^{*}}$ Expression base station and k ^*This communication link of individual relaying is at n ^*Transmitted power on the number of sub-carrier,

Expression base station and k ^*This communication link of individual relaying is at n ^*Channel gain on the number of sub-carrier, Expression base station and j this communication link of user are at n ^*Transmitted power on the number of sub-carrier,

Expression base station and j this communication link of user are at n ^*Channel gain on the number of sub-carrier,

Represent that j user is through k ^*Individual relaying is at n ^*Transmitted power on the number of sub-carrier, the size of its value does

Represent that j user is through k ^*Individual relaying is at n ^*Channel gain on the number of sub-carrier.

5.-3, remaining subcarrier is distributed: b1, obtain δ according to single order KKT necessary condition C1 _{K, j, n}=β _n-(1+ μ _j) R _{K, j, n}, obtain according to single order KKT necessary condition C2 then

Obtain according to single order KKT necessary condition C3 again

B2, according to δ _{K, j, n}=β _n-(1+ μ _j) R _{K, j, n}With

Obtain β _n=(1+ μ _j) R _{K, j, n}, and make w _jThe speed weighting factor of representing j user, w _j=Q _j-R _j, then will

Be reduced to

Wherein, R _jThe actual speed rate of representing j user; B3, according to β _n=(1+ μ _j) R _{K, j, n}With

Confirm to work as μ _jThe n number of sub-carrier is distributed to j at=0 o'clock ^*Individual user and corresponding k ^*Individual relaying makes

Work as μ _j>The n number of sub-carrier distributed to the maximum user of momentary rate and corresponding relay with the total speed of maximization system at 0 o'clock, be respectively j ^*Individual user and k ^*Individual relaying, wherein,

Represent j ^*Individual user's speed weighting factor, wherein, 1≤j ^*≤M; B4, find out the minimum speed limit that will reach and the maximum user of actual speed rate difference, suppose that the user who finds out is j ^*Individual user then has j ^*=arg max w _j, wherein, 1≤j ^*≤M, argmax w _jThe user of institute's minimum speed limit that will reach and actual speed rate difference maximum is found out in expression; The j that b5, judgement are found out ^*Individual user's speed weighting factor

Whether greater than 0, if, show that then each with unmet minimum speed limit demand per family, continues execution in step b6 then, otherwise, show that each with having satisfied the minimum speed limit demand per family, continues execution in step b7 then; B6, find out and satisfy condition

Subcarrier and corresponding relaying, suppose that the subcarrier of finding out is n ^*Number of sub-carrier, and corresponding relaying is k ^*Individual relaying is then with n ^*Number of sub-carrier is distributed to j ^*Individual user, wherein,

J is found out in expression ^*Individual user obtains maximum subcarrier of momentary rate and corresponding relaying from the base station, be respectively n ^*Number of sub-carrier and k ^*Individual relaying,

Represent j ^*Individual user is through the momentary rate of k relaying on the n number of sub-carrier; Then with n ^*Number of sub-carrier is gathered Ω from subcarrier _NMiddle deletion; Then order is used to characterize j ^*Individual user and corresponding k ^*Individual relaying is at n ^*The proportional numbers that takies on the number of sub-carrier And upgrade j ^*Individual user's actual speed rate

Wherein,

In "=" be assignment, the left side

J after expression is upgraded ^*Individual user's actual speed rate, the right

J before expression is upgraded ^*Individual user's actual speed rate,

Initial value be 0,

Represent j ^*Individual user is through k ^*Individual relaying is at n ^*Momentary rate on the number of sub-carrier, $R_{k^{*},j^{*},n^{*}}=\frac{1}{2}\mathrm{Min}\{\mathrm{Log}2(1+p_{S,M+k^{*},n^{*}}{H}_{S,M+k^{*},n^{*}}),\mathrm{Log}2(1+p_{S,j^{*},n^{*}}{H}_{S,j^{*},n^{*}}+p_{k^{*},j^{*},n^{*}}{H}_{k^{*},j^{*},n^{*}})\},$

Expression base station and k ^*This communication link of individual relaying is at n ^*Transmitted power on the number of sub-carrier,

Expression base station and k ^*This communication link of individual relaying is at n ^*Channel gain on the number of sub-carrier,

Expression base station and j ^*This communication link of individual user is at n ^*Transmitted power on the number of sub-carrier,

Expression base station and j ^*This communication link of individual user is at n ^*Channel gain on the number of sub-carrier,

Represent j ^*Individual user is through k ^*Individual relaying is at n ^*Transmitted power on the number of sub-carrier,

Represent j ^*Individual user is through k ^*Individual relaying is at n ^*Channel gain on the number of sub-carrier; Continue execution in step b8 again; B7, find out momentary rate maximum user and corresponding relaying, suppose that the n number of sub-carrier is remaining subcarrier, and to be assumed to be the maximum user of its momentary rate of finding out be j for remaining subcarrier ^*Individual user, and corresponding relaying is k ^*Individual relaying then has (k ^*, j ^*)=argmaxR _{K, j, n}, wherein, (k ^*, j ^*)=arg maxR _{K, j, n}Be expressed as the n number of sub-carrier and find out maximum user of momentary rate and corresponding relaying, be respectively j ^*Individual user and k ^*Individual relaying; Then the n number of sub-carrier is gathered Ω from subcarrier _NMiddle deletion; Then order is used to characterize j ^*Individual user and corresponding k ^*The proportional numbers that individual relaying takies on the n number of sub-carrier

And upgrade j ^*Individual user's actual speed rate

Wherein,

In "=" be assignment, the left side

J after expression is upgraded ^*Individual user's actual speed rate, the right

J before expression is upgraded ^*Individual user's actual speed rate, Initial value be 0,

Represent j ^*Individual user is through k ^*The momentary rate of individual relaying on the n number of sub-carrier, $R_{k^{*},j^{*},n}=\frac{1}{2}\mathrm{Min}\{\mathrm{Log}2(1+p_{S,M+k^{*},n}{H}_{S,M+k^{*},n}),\mathrm{Log}2(1+p_{S,j^{*},n}{H}_{S,j^{*},n}+p_{k^{*},j^{*},n}{H}_{k^{*},j^{*},n})\},$ $p_{S,M+k^{*},n}$ Expression base station and k ^*The transmitted power of this communication link of individual relaying on the n number of sub-carrier,

Expression base station and k ^*The channel gain of this communication link of individual relaying on the n number of sub-carrier,

Expression base station and j ^*The transmitted power of this communication link of individual user on the n number of sub-carrier,

Expression base station and j ^*The channel gain of this communication link of individual user on the n number of sub-carrier,

Represent j ^*Individual user is through k ^*The transmitted power of individual relaying on the n number of sub-carrier,

Represent j ^*Individual user is through k ^*The channel gain of individual relaying on the n number of sub-carrier; Continue execution in step b8 again; B8, judgement subcarrier set Ω _NWhether be empty set, if, show that then subcarrier allocation and relay selection finish, otherwise, return step b4 and continue to carry out.

Below for the inventive method is carried out emulation experiment, with the validity and the feasibility of explanation the inventive method.

Adopt 6 footpath fading channels, maximum doppler frequency is 30Hz, and it is 5 μ s that time delay is expanded, the single cellular downlink communication system of many cooperating relay available bandwidth B=1MHz, bit error rate BER=10 ^-3, white Gaussian noise one-sided power spectrum density N ₀=10 ^-8, the relaying number is 3 (K=3), number of users is 6 (M=6).

Fig. 2 described the inventive method that 100 repeated experiments obtain, guarantee fairness with the resource allocation algorithm of QoS, static resource allocation method under the user rate that obtains and the comparative result of minimum speed limit demand, system's available subcarrier number is 256 (N=256).As can be seen from Figure 2 the user rate of the inventive method acquisition can reach minimum user rate demand, and traditional static resource allocation method can only make the individual user reach needed speed.This The simulation experiment result explanation the inventive method is a kind of adaptive approach that effectively can satisfy the different user rate requirement.

It is 256 o'clock that Fig. 3 has provided system's available subcarrier number; The comparison of algorithm and the system total speed of static resource allocation method under different signal to noise ratios in the inventive method, [9], as can be seen from Figure 3 the inventive method obtains more traditional static resource allocation method and [9] the middle higher system's speed of algorithm.This The simulation experiment result shows that the inventive method is a kind of resource allocation methods that effectively can improve the total speed of system.

Can find out that by simulation result resource allocation methods of the present invention can satisfy under the situation of each user's QoS requirement, obtains high power system capacity.

Among above-mentioned Fig. 2 and Fig. 3 in [9] algorithm be meant " the An Efficient Resource Allocation Algorithm for OFDMA Cooperative Relay Networks with Fairness and QoS Guaranteed " that people such as Asem A.Salah delivered on Network Applications Protocols and Services 188-192 page or leaf in September, 2010, i.e. " a kind of resource allocation algorithm that effectively guarantees fairness with QoS in the OFDMA cooperating relay network ".

Claims (3)

1. the resource allocation methods of a cooperating relay orthogonal frequency division multiple access system is characterized in that may further comprise the steps:

1. according to the minimum quality of service requirement of different user in the cooperating relay OFDMA system, set up optimize allocation of resources

$\max \underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a_{k,j,n}}^{\′}{R}_{k,j,n}$

The constraints that satisfies:

A1: $\underset{j=1}{\overset{M+K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{p}_{S,j,n}\≤P_T$

Model: A2:

wherein; Max () is for getting max function, and K representes cooperating relay

A3:a _k，j,n'∈{0,1}

A4: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{a_{k,j,n}}^{\′}=1$

A5: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a_{k,j,n}}^{\′}{R}_{k,j,n}\≥Q_j$

Relaying number in the OFDMA system, K>=1, M representes the user's number in the cooperating relay OFDMA system, M>1, N representes the subcarrier number in the cooperating relay OFDMA system, N>1; a _{K, j, n}' the integer factor before expression is lax, whether it is used to characterize n number of sub-carrier and k relaying by j CU, P _TThe total emission power at place, expression base station, P _{K, T}The transmitting power of representing k relaying place, Q _jThe minimum speed limit value of representing j user; Constraints A1 representes the total emission power constraint at base station place, in constraints A1, and when 1≤j≤M, p _{S, j, n}Expression base station and the transmitted power of j this communication link of user on the n number of sub-carrier, when M+1≤j≤M+K, p _{S, j, n}Expression base station and the transmitted power of k this communication link of relaying on the n number of sub-carrier; Constraints A2 representes the transmitted power constraint at each relaying place; Whether constraints A3 is used to characterize n number of sub-carrier and k relaying by j CU, a _{K, j, n}N number of sub-carrier and k relaying are represented not by j CU in '=0, a _{K, j, n}'=1 expression n number of sub-carrier and k relaying are by j CU; Constraints A4 representes that a number of sub-carrier can only be taken by a user and corresponding relay at most; Constraints A5 representes the minimum quality of service requirement of different user, and it is described as the minimum speed limit demand of different user; R _{K, j, n}Represent j user through k relaying on the n number of sub-carrier momentary rate and $R_{k,j,n}=\frac{1}{2}\min \{\log 2(1+p_{S,M+k,n}{H}_{S,M+k,n}),\log 2(1+p_{S,j,n}{H}_{S,j,n}+p_{k,j,n}{H}_{k,j,n})\},$ Min () is for getting minimum value function, p _{S, M+k, n}Expression base station and the transmitted power of k this communication link of relaying on the n number of sub-carrier, H _{S, M+k, n}Expression base station and the channel gain of k this communication link of relaying on the n number of sub-carrier, p _{S, j, n}Expression base station and the transmitted power of j this communication link of user on the n number of sub-carrier, H _{S, j, n}Expression base station and the channel gain of j this communication link of user on the n number of sub-carrier, p _{K, j, n}Represent that j user is through the transmitted power of k relaying on the n number of sub-carrier, H _{K, j, n}Represent that j user is through the channel gain of k relaying on the n number of sub-carrier;

2. with the lax preceding integer factor a in the above-mentioned optimize allocation of resources model _{K, j, n}' lax be a variable between [0,1], be designated as a _{K, j, n}, and the power that adopts the constant power distribution method to equate for each subcarrier allocation, the optimization that obtains simplifying

$\underset{a_{k,j,n}}{\max }\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}$

The constraints that satisfies:

Resource allocator model: B1:a _{K, jn}∈ [0,1], wherein,

Expression is with a _{K, j, n}For optimization variable

B2: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{a}_{k,j,n\≤}1$

B3: $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a_{k,j,n}R}_{k,j,n}\≥Q_j$

Get max function, a _{K, j, n}Be used to characterize j user and corresponding k the proportional numbers that relaying takies on the n number of sub-carrier; Constraints B1 representes a _{K, j, n}Value be [0,1] any numerical value in interval; Constraints B2 representes that a number of sub-carrier can be taken by a plurality of users and corresponding relay; Constraints B3 representes the minimum speed limit demand of different user;

3. construct a Lagrange's equation relevant, be expressed as with the optimize allocation of resources model of above-mentioned simplification: $\begin{array}{c}L(a_{k,j,n},{\mathrm{\β}}_n,{\mathrm{\δ}}_{k,j,n},{\mathrm{\μ}}_j)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}+\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\β}}_n(1-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n})\\ +\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\δ}}_{k,j,n}{a}_{k,j,n}+\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{\mathrm{\μ}}_j(\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}-Q_j)\end{array},$ Wherein, β _nExpression

Lagrangian, δ _{K, j, n}Expression a _{K, j, n}Lagrangian, μ _jExpression $\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}-Q_j$ Lagrangian;

4. will $\begin{array}{c}L(a_{k,j,n},{\mathrm{\β}}_n,{\mathrm{\δ}}_{k,j,n},{\mathrm{\μ}}_j)=\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}+\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\β}}_n(1-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n})\\ +\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{j=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\δ}}_{k,j,n}{a}_{k,j,n}+\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{\mathrm{\μ}}_j(\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n}-Q_j)\end{array}$ To a _{K, j, n}Carry out differentiate, obtain corresponding single order KKT necessary condition, be expressed as: $\begin{array}{c}C1:R_{k,j,n}-{\mathrm{\β}}_n+{\mathrm{\δ}}_{k,j,n}+{\mathrm{\μ}}_j{R}_{k,j,n}=0\\ C2:{\mathrm{\δ}}_{k,j,n}{a}_{k,j,n}=0\\ C3:{\mathrm{\μ}}_j(Q_j-\underset{k=1}{\overset{K}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{a}_{k,j,n}{R}_{k,j,n})=0\end{array},$ Here, 1≤k≤K, 1≤j≤M, 1≤n≤N;

5. turn to only relaying of subcarrier and selection that each user distributes an optimum according to the momentary rate maximum, according to single order KKT necessary condition remaining subcarrier is divided to be equipped with then to guarantee that each user can both satisfy the minimum speed limit demand.

2. the resource allocation methods of a kind of cooperating relay orthogonal frequency division multiple access system according to claim 1; It is characterized in that turning to only relaying of subcarrier and selection that each user distributes an optimum according to the momentary rate maximum during described step is 5., according to single order KKT necessary condition be then the detailed process that remaining subcarrier distributes:

5.-1, initialization: make sub-carrier set be combined into Ω _N, user's set is Ω _M, relay collection is Ω _KMaking the total emission power at place, base station is P _T, the performance number size of distributing on each subcarrier when then adopting the constant power distribution method does

Wherein, N representes the subcarrier number in the cooperating relay OFDMA system, and M representes the user's number in the cooperating relay OFDMA system, and K representes the relaying number in the wireless cooperation relaying OFDMA system;

5.-2, turning to each user according to the momentary rate maximum distributes the subcarrier of an optimum and selects only relaying a: a1, calculates each user and obtain maximum subcarrier of momentary rate and corresponding relaying from the base station; And the subcarrier that momentary rate is maximum gives corresponding user as the subcarrier allocation of optimum, again from subcarrier set Ω _NThe optimum subcarrier of middle deletion supposes that j user obtains the maximum subcarrier of momentary rate from the base station be n ^*Number of sub-carrier, corresponding relaying are k ^*Individual relaying then has (k ^*, n ^*)=argmaxR _{K, j, n}, then with n ^*Number of sub-carrier is given j user as the subcarrier allocation of optimum, and with corresponding k ^*Individual relaying is as only relaying, again with n ^*Number of sub-carrier is gathered Ω from subcarrier _NMiddle deletion, wherein, 1≤n ^*≤N, 1≤k ^*≤K, arg () is for getting parametric function, and max () is for getting max function, (k ^*, n ^*)=argmaxR _{K, j, n}Expression is found out j user and is obtained maximum subcarrier of momentary rate and corresponding relaying from the base station, is respectively n ^*Number of sub-carrier and k ^*Individual relaying, R _{K, j, n}J user is through the momentary rate of k relaying on the n number of sub-carrier in the expression expression; A2, then order is used to characterize j user and corresponding k ^*Individual relaying is at n ^*The proportional numbers that takies on the number of sub-carrier

And upgrade j user's actual speed rate R _j,

Wherein,

In "=" be assignment, the R on the left side _jJ user's after expression is upgraded actual speed rate, the R on the right _jJ user's before expression is upgraded actual speed rate, R _jInitial value be 0,

Represent that j user is through k ^*Individual relaying is at n ^*Momentary rate on the number of sub-carrier, $R_{k^{*},j,n^{*}}=\frac{1}{2}\min \{\log 2(1+p_{S,M+k^{*},n^{*}}{H}_{S,M+k^{*},n^{*}}),\log 2(1+p_{S,j,n^{*}}{H}_{S,j,n^{*}}+p_{k^{*},j,n^{*}}{H}_{k^{*},j,n^{*}})\},$ $p_{S,M+k^{*},n^{*}}$ Expression base station and k ^*This communication link of individual relaying is at n ^*Transmitted power on the number of sub-carrier,

Expression base station and k ^*This communication link of individual relaying is at n ^*Channel gain on the number of sub-carrier,

Expression base station and j this communication link of user are at n ^*Transmitted power on the number of sub-carrier,

Expression base station and j this communication link of user are at n ^*Channel gain on the number of sub-carrier,

Represent that j user is through k ^*Individual relaying is at n ^*Transmitted power on the number of sub-carrier, the size of its value does

Represent that j user is through k ^*Individual relaying is at n ^*Channel gain on the number of sub-carrier;

5.-3, remaining subcarrier is distributed: b1, obtain δ according to single order KKT necessary condition C1 _{K, j, n}=β _n-(1+ μ _j) R _{K, j, n}, obtain according to single order KKT necessary condition C2 then

Obtain according to single order KKT necessary condition C3 again

B2, according to δ _{K, j, n}=β _n-(1+ μ _j) R _{K, j, n}With

Obtain β _n=(1+ μ _j) R _{K, j, n}, and make w _jThe speed weighting factor of representing j user, w _i=Q _j-R _j, then will

Be reduced to

Wherein, R _jThe actual speed rate of representing j user; B3, according to β _n=(1+ μ _j) R _{K, j, n}With

Confirm to work as μ _jThe n number of sub-carrier is distributed to j at=0 o'clock ^*Individual user and corresponding k ^*Individual relaying makes

Work as μ _jDuring＞O the n number of sub-carrier is distributed to the maximum user of momentary rate and corresponding relay with the total speed of maximization system, be respectively j ^*Individual user and k ^*Individual relaying, wherein,

Represent j ^*Individual user's speed weighting factor, wherein, 1≤j ^*≤M; B4, find out the minimum speed limit that will reach and the maximum user of actual speed rate difference, suppose that the user who finds out is j ^*Individual user then has j ^*=argmax w _j, wherein, 1≤j ^*≤M, argmax w _jThe user of institute's minimum speed limit that will reach and actual speed rate difference maximum is found out in expression; The j that b5, judgement are found out ^*Individual user's speed weighting factor

Whether greater than 0, if, show that then each with unmet minimum speed limit demand per family, continues execution in step b6 then, otherwise, show that each with having satisfied the minimum speed limit demand per family, continues execution in step b7 then; B6, find out and satisfy condition

Subcarrier and corresponding relaying, suppose that the subcarrier of finding out is n ^*Number of sub-carrier, and corresponding relaying is k ^*Individual relaying is then with n ^*Number of sub-carrier is distributed to j ^*Individual user, wherein,

J is found out in expression ^*Individual user obtains maximum subcarrier of momentary rate and corresponding relaying from the base station, be respectively n ^*Number of sub-carrier and k ^*Individual relaying,

Represent j ^*Individual user is through the momentary rate of k relaying on the n number of sub-carrier; Then with the, n ^*Number of sub-carrier is gathered Ω from subcarrier _NMiddle deletion; Then order is used to characterize j ^*Individual user and corresponding k ^*Individual relaying is at n ^*The proportional numbers that takies on the number of sub-carrier

And upgrade n ^*Individual user's actual speed rate

Wherein,

In "=" be assignment, the left side

J after expression is upgraded ^*Individual user's actual speed rate, the right

J before expression is upgraded ^*Individual user's actual speed rate,

Initial value be 0,

Represent j ^*Individual user is through k ^*Individual relaying is at n ^*Momentary rate on the number of sub-carrier, $R_{k^{*},j^{*},n^{*}}=\frac{1}{2}\mathrm{Min}\{\mathrm{Log}2(1+p_{S,M+k^{*},n^{*}}{H}_{S,M+k^{*},n^{*}}),\mathrm{Log}2(1+p_{S,j^{*},n^{*}}{H}_{S,j^{*},n^{*}}+p_{k^{*},j^{*},n^{*}}{H}_{k^{*},j^{*},n^{*}})\},$

Expression base station and k ^*This communication link of individual relaying is at n ^*Transmitted power on the number of sub-carrier,

Expression base station and k ^*This communication link of individual relaying is at n ^*Channel gain on the number of sub-carrier,

Expression base station and j ^*This communication link of individual user is at n ^*Transmitted power on the number of sub-carrier,

Expression base station and j ^*This communication link of individual user is at n ^*Channel gain on the number of sub-carrier,

Represent j ^*Individual user is through k ^*Individual relaying is at n ^*Transmitted power on the number of sub-carrier,

Represent j ^*Individual user is through k ^*Individual relaying is at n ^*Channel gain on the number of sub-carrier; Continue execution in step b8 again; B7, find out momentary rate maximum user and corresponding relaying, suppose that the n number of sub-carrier is remaining subcarrier, and to be assumed to be the maximum user of its momentary rate of finding out be j for remaining subcarrier ^*Individual user, and corresponding relaying is k ^*Individual relaying then has (k ^*, j ^*)=argmaxR _{K, j, n '}, wherein, (k ^*, j ^*)=argmaxR _{K, j, n'}Be expressed as the n number of sub-carrier and find out maximum user of momentary rate and corresponding relaying, be respectively j ^*Individual user and k ^*Individual relaying; Then the n number of sub-carrier is gathered Ω from subcarrier _NMiddle deletion; Then order is used to characterize j ^*Individual user and corresponding k ^*The proportional numbers that individual relaying takies on the n number of sub-carrier

And upgrade j ^*Individual user's actual speed rate

Wherein,

In "=" be assignment, the left side J after expression is upgraded ^*Individual user's actual speed rate, the right

J before expression is upgraded ^*Individual user's actual speed rate, Initial value be 0,

Represent j ^*Individual user is through k ^*The momentary rate of individual relaying on the n number of sub-carrier, $R_{k^{*},j^{*},n}=\frac{1}{2}\mathrm{Min}\{\mathrm{Log}2(1+p_{S,M+k^{*},n}{H}_{S,M+k^{*},n}),\mathrm{Log}2(1+p_{S,j^{*},n}{H}_{S,j^{*},n}+p_{k^{*},j^{*},n}{H}_{k^{*},j^{*},n})\},$ $p_{S,M+k^{*},n}$ Expression base station and k ^*The transmitted power of this communication link of individual relaying on the n number of sub-carrier,

Expression base station and k ^*The channel gain of this communication link of individual relaying on the n number of sub-carrier, Expression base station and j ^*The transmitted power of this communication link of individual user on the n number of sub-carrier,

Expression base station and j ^*The channel gain of this communication link of individual user on the n number of sub-carrier,

Represent j ^*Individual user is through k ^*The transmitted power of individual relaying on the n number of sub-carrier,

Represent j ^*Individual user is through k ^*The channel gain of individual relaying on the n number of sub-carrier; Continue execution in step b8 again; B8, judgement subcarrier set Ω _NWhether be empty set, if, show that then subcarrier allocation and relay selection finish, otherwise, return step b4 and continue to carry out.

3. the resource allocation methods of a kind of cooperating relay orthogonal frequency division multiple access system according to claim 1 and 2 is characterized in that the value of K was 3,4 or 5 during described step 1., and the value of M is 6,8,10 or 12, and the value of N is 128,256,512 or 1024.

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