WO2012159328A1

WO2012159328A1 - Method and device for wireless resources distribution

Info

Publication number: WO2012159328A1
Application number: PCT/CN2011/077166
Authority: WO
Inventors: 张舜卿; 陈雁
Original assignee: 华为技术有限公司
Priority date: 2011-07-14
Filing date: 2011-07-14
Publication date: 2012-11-29
Also published as: CN103004275B; CN103004275A

Abstract

Disclosed in the present invention are a method and a device for wireless resources distribution, and the present invention relates to the Orthogonal Frequency Division Multiple Access (OFDMA) wireless communication field, for achieves a purpose that a down-link OFDMA system can distribute the wireless resource according to the optimal scheme of the energy efficiency. The said wireless resources distribution method comprises the following steps: according to the corresponding relationship of the optimal value between the system throughput and energy efficiency, the system optimal throughput is determined; when the system is in the optimal throughput, according to the maximum power decrease priority algorithm, the sub-carrier set and the power distribution set are determined; according to the determined sub-carrier set and the power distribution set, the sub-carrier and the transmission power is distributed to users. The scheme provided by the present invention is suitable for the scene of down-link OFDMA system distribution wireless resources.

Description

TECHNICAL FIELD The present invention relates to the field of OFDMA wireless communications, and in particular, to a wireless resource allocation method and apparatus.

Background technique

The OFDMA (Orthogonal Frequency Division Multiple Access) technology is a multi-carrier transmission technology in a wireless environment, which implements multi-user access by allocating a certain number of subcarriers to each user. In the prior art, for a downlink OFDMA system, a two-step, that is, a radio resource allocation scheme in which subcarriers are reassigned power is first allocated. Among them, the power allocation is mainly based on the Margin Adaptive Enhanced CHC algorithm (Cross Generation Heterogeneous recombination Cataclysmic mutation), which can ensure the minimum throughput requirement per user. However, under normal circumstances, the transmission of minimum throughput is not the most energy efficient transmission. From the perspective of energy efficiency, this wireless resource allocation scheme is not the most energy efficient solution.

SUMMARY OF THE INVENTION Embodiments of the present invention provide a method and apparatus for radio resource allocation for achieving the purpose of an OFDMA system capable of allocating radio resources according to an energy efficient scheme.

In order to achieve the above object, the embodiment of the present invention adopts the following technical solutions:

In one aspect, a method for allocating radio resources provided by the present invention includes:

The optimal throughput rate of the system is determined according to the correspondence between the system throughput rate and the intermediate value of the energy efficiency;

When the system is in an optimal throughput rate, determining a set of subcarriers and a set of power allocations according to a maximum power reduction priority algorithm;

Subcarriers and transmit power are allocated to the user in accordance with the determined set of subcarriers and the set of power allocations.

In another aspect, a wireless resource allocation apparatus provided by the present invention includes:

a first determining unit, configured to perform a correspondence between a system throughput rate and an intermediate energy optimal value Relationship determines the optimal throughput rate of the system;

a second determining unit, configured to determine a subcarrier set and a power allocation set according to a maximum power reduction priority algorithm when the system is in an optimal throughput rate;

And an allocating unit, configured to allocate a subcarrier and a transmit power to the user according to the determined set of subcarriers and the set of power allocations. Embodiments of the present invention provide a method and an apparatus for allocating radio resources, and determining an optimal throughput rate according to a correspondence between a system throughput rate and an intermediate energy optimal value. When the system is in an optimal throughput rate, The maximum power reduction priority group determines the set of subcarriers and the power allocation set, and performs radio resource allocation according to the determined result, so as to ensure that the downlink OFDM A system can allocate radio resources according to the energy efficient scheme.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set forth in the description of the claims Other drawings can also be obtained from these drawings on the premise of creative labor. 1 is a flowchart of a method for allocating radio resources according to an embodiment of the present invention; FIG. 2 is a schematic diagram of analysis of a quasi-convex characteristic of an energy-efficient intermediate optimal function; FIG. 3 is a method for determining a system using a dichotomy when a derivative is greater than 0. Flow chart of method for superior throughput rate;

4 is a flowchart of a maximum power reduction priority algorithm; FIG. 5 is a block diagram of a wireless resource allocation apparatus according to an embodiment of the present invention.

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. example. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

As shown in FIG. 1, a radio resource allocation method provided by the present invention includes: 101. Determine an optimal throughput rate of the system according to a correspondence between a system throughput rate and an intermediate energy optimal value;

In all embodiments of the present invention, the throughput rate refers to the amount of data downlinked per unit time; the system throughput rate refers to the amount of data downlinked by the system per unit time; and the user throughput rate refers to the amount of data that the base station downlinks to the user per unit time. And system throughput is the sum of user throughput for all users. For each system throughput rate, there is a value that makes the system energy efficient under the system throughput rate. This value is called the energy efficiency intermediate optimal value. The largest of the energy efficiency intermediate optimal values is the energy efficiency optimal value, and the system throughput rate corresponding to the energy efficiency optimal value is the system optimal throughput rate.

This step can be specifically:

First, determine the minimum throughput of the system;

Multi-user hybrid services include real-time traffic with fixed throughput requirements and non-real-time traffic with minimum throughput requirements. For the real-time service with fixed throughput requirements, the minimum throughput rate of the user is the required fixed throughput rate for the user; for the non-real-time service with the minimum throughput requirement, the minimum throughput rate of the user is required. The minimum throughput rate for this user. And, the system minimum throughput rate is the sum of the minimum throughput rates of all users.

Then, obtaining a derivative of the energy efficiency intermediate optimal function at the minimum throughput rate of the system; the energy efficiency intermediate optimal function is a correspondence between a system throughput rate and an energy efficiency intermediate optimal value obtained by the energy efficiency function;

Preferably, the energy efficiency function is a ratio of a system throughput rate to a total system transmit power, and the total transmit power of the system is the sum of the system static circuit power. The system static circuit power is the power corresponding to when the system does not transmit power to any user. Considering the static circuit power of the system in this embodiment, the theoretical conclusion can be made closer to the actual system scenario.

The energy function can be an expression like this:

_ R

E ^E — P + P _C where, represents the system throughput, P represents the system transmit power, and represents the system static circuit power.

The intermediate energy efficiency intermediate value refers to a value that maximizes the energy efficiency function at the throughput rate of the system considering all the different subcarrier allocation schemes and transmission power allocation schemes under the condition that the system throughput rate is constant. Therefore, the expression of the energy efficiency intermediate optimal function is:

Where p is a subcarrier allocation indication matrix and P is a system transmit power matrix. In the embodiment of the present invention, for example, the number of subcarriers is N, and the number of users is, then p is a subcarrier allocation indication matrix corresponding to allocating N subcarriers to users, and P is to allocate N subcarriers to users. The corresponding system transmit power matrix.

Further, the constraint condition of the energy efficiency intermediate optimal function includes:

(1) Each subcarrier is assigned at most to a unique user;

(2) The throughput rate on each subcarrier is non-negative;

(3) The system transmit power is less than or equal to the system transmit power peak; the sum of the user's weight values; the weight value is used to indicate fairness between users;

Specifically, the weight value of the user may be a product of a difference between the optimal throughput rate of the system and a minimum throughput rate of the system and a user experience factor of the user; the minimum throughput of the system is a minimum of all users. The sum of throughput rates;

For a non-real-time service with a minimum throughput requirement, a user's user experience factor is the ratio of the user's user's minimum throughput rate divided by the system's minimum throughput rate; or, a user's user experience factor is the user's user experience factor. The amount of data in the queued queue divided by the amount of data in the queued queue of the system; the amount of data in the queued queue of the system is the sum of the amount of data in the queued queues of all users. In the embodiment of the present invention, the definition of the former user experience factor is taken as an example for description. In addition, it should be noted that for a real-time service with a fixed throughput requirement, the user's user experience factor is recorded as 0.

The most common expression for the above energy efficiency is as follows:

( 2 ) r _k>n > 0, Vk, n,

(3) ∑∑P _k ^ _n ≤P _T , Where ∑ Pk ^r k where, represents the number of all users, N represents the number of all subcarriers, A represents the user number, "represents the subcarrier number; P represents whether the "subcarrier" is assigned to the first user, and if so, ^ Is 1, if no, then 0, all constitute a subcarrier allocation indication matrix P; ^ indicates the throughput rate of the "subcarrier allocated to the A user"; % indicates the user experience factor of the A user, ^ indicates the User minimum throughput of A users; ί3⁄4 represents the weight value, and may be the difference between the current throughput rate of the system and the minimum throughput rate of the system; _Α „ indicates the transmit power value assigned to the first user by the nth subcarrier, all The system transmit power matrix Ρ is formed; indicating the system transmit power peak. The current throughput of the system is the currently determined system throughput.

In addition, for the energy efficiency intermediate optimal function to provide the throughput rate, you can use the integer function sgn(t?7 (i?)/ti?); ; _E (R + AR)- ; _E (R)

Άη _Ε * _Ε (i?) I dR= lim

AR

R

AR-AP-

P+P

Lim

(^P ₊ P _C +AP)AR

In order to simplify the computational complexity, first set a relatively small and then calculate the corresponding increase in the non-real-time user's throughput rate Δ3⁄4 according to the user experience factor, and then use the water injection algorithm for Δ3⁄4 to obtain each user. AP, add ΔΡ of all users to get ΔΡ, and finally calculate the sign of + to get the comparison between derivative and 0: if positive, the derivative is greater than 0; if negative, the derivative is less than 0; If 0, the derivative is equal to 0.

Finally, the optimal throughput rate of the system is determined according to the quasi-convexity characteristic of the energy efficiency intermediate optimal function and the comparison result of the derivative with 0.

The quasi-upward convexity characteristic of the energy efficiency intermediate optimal function is to reduce the complexity of the algorithm and analyze the characteristics of the function obtained by the energy intermediate optimal function. The quasi-convex characteristic means that a function must be a characteristic of an up-convex function.

Referring to the analysis of the quasi-convex characteristics of the energy efficiency intermediate optimal function shown in Figure 2, The following conclusions were obtained:

It should be noted that for the minimum throughput of the system, the system throughput rate that can be obtained when the system transmit power peak is transmitted under the condition that the energy efficiency intermediate optimal function satisfies all the constraints.

The maximum throughput of the system under system availability, that is, the area determined between and is the system availability zone.

Referring to FIG. 2( a ), it can be known that when the energy efficiency intermediate optimal function has a derivative of the system minimum throughput less than or equal to 0, the energy efficiency intermediate optimal function is a subtraction function in the system available region. The energy efficiency intermediate optimal function takes the maximum value at the minimum throughput rate of the system, that is, the energy efficiency optimal value U

Referring to FIG. 2(b), it can be known that when the energy efficiency intermediate optimal function has a derivative greater than 0 at the minimum throughput rate of the system and a derivative at the maximum throughput rate of the system is greater than or equal to 0, in the system available area. The energy efficiency intermediate optimal function is an increasing function. At this time, the energy efficiency intermediate optimal function obtains the maximum value at the maximum throughput rate of the system, that is, the energy efficiency optimal value R _best ;

Referring to FIG. 2(c), it can be known that when the energy efficiency intermediate optimal function has a derivative at the minimum throughput rate of the system greater than 0 and the derivative at the maximum throughput rate of the system is less than 0, the energy efficiency is available in the system available area. The intermediate optimal function is the first increase and then decrease function. At this time, the system throughput rate that makes the energy efficiency optimal value is between R and R.

According to the above analysis, the quasi-convexity characteristic according to the energy efficiency intermediate optimal function and the comparison result of the derivative with 0 determine the optimal throughput rate of the system including two cases:

In the first case, if the derivative of the energy efficiency intermediate optimal function at the system minimum throughput is less than or equal to 0, then according to the quasi-convex characteristic of the energy efficiency intermediate optimal function, the optimal throughput rate R _best of the system can be determined as The system has a minimum throughput rate;

In the second case, if the derivative of the energy efficiency intermediate optimal function at the minimum throughput of the system is greater than 0, then according to the quasi-upward characteristic of the energy efficiency intermediate optimal function, the system transmit power is less than or equal to the system transmit power. Under the premise of peak value, the dichotomy method can be used to determine the optimal throughput rate _{rf of the} system.

For the specific case in the case where the derivative is greater than 0, as shown in FIG. 3, it may include:

3001, determining a first boundary value and a second boundary value of the dichotomy method? 2; wherein, the first boundary value is a system minimum throughput rate, that is, ?l=, and the second boundary value is such that the energy efficiency intermediate optimal function is to the system The value of a system throughput rate with a derivative of throughput less than 0, ie ?2 = ;

3002. Obtain an average value of the first boundary value and the second boundary value, ie, = (i?l + i?2)/2; 3003. In the case of the average, obtain a set of subcarriers and a power allocation set determined by using a maximum power reduction priority algorithm, and calculate a transmit power of the system; where, a set of subcarriers determined by using a maximum power reduction priority algorithm and The method of power allocation set can refer to the description in step 102.

3004, determining whether the system transmit power is greater than a system transmit power peak; if the system transmit power is greater than the system transmit power peak, proceed to step 3005, and if not, perform step 3006;

3005. The first boundary value is unchanged, and the second boundary value is set to the average value, that is, ?2 = ?, and all steps of step 3002 to the step are performed until the obtained system transmit power is less than or equal to the system transmit power peak value;

3006. If the system transmit power is less than or equal to the system transmit power peak, determine whether the binary method converges;

If not, proceed to step 3007; if convergence, proceed to step 3008;

3007. Calculate the derivative of the energy efficiency intermediate optimal function to the system throughput rate at the last mean ^; in the case where the derivative is less than 0, the first boundary value is unchanged, and the second boundary value is set to the last average value. 2 = ?^, in the case where the derivative is greater than 0, the first boundary value is set to the last average value, ie, l = , and then all steps of step 3002 to this step are cycled until the dichotomy converges;

3008, the end and the last average value obtained is the optimal throughput rate of the system ^^, ie

Rbest ~ ^ave* °

102. When the system is in an optimal throughput rate, determining a set of stator carriers and a power allocation set according to a maximum power reduction priority algorithm;

As shown in FIG. 4, the maximum power reduction priority algorithm includes:

4001. Initializing system variables; the system variables include: number of users, user throughput rate per user, number of subcarriers allocated by each user, set of subcarriers allocated by each user &, assigned by each user Transmit power set 1, total number of subcarriers, unallocated subcarrier set 5, channel information assigned to any user per subcarrier „, number of users of unallocated subcarriers;

Specifically, the initialization K, Ν, _{hk n} , s . & is an empty set, R _k = _k + ω , ^Ρ is an empty set, m _k = 0, K _E = K. Wherein, it may be the difference between the current throughput rate of the system and the minimum throughput rate of the system.

In the maximum power reduction priority algorithm, the initial user throughput rate for each user Initialization depends on the application scenario.

For example, in step 3003, the maximum power reduction priority algorithm is applied, which initializes the system variables, and the current throughput rate of the system at initialization is the system throughput rate determined for each cycle.

For another example, the maximum power reduction priority algorithm is applied in this step 102. During the initialization of the system variable, the current throughput of the system at initialization is the optimal throughput rate determined by step 101; that is, each is initialized in step 102. User's user throughput rate = A + d

4002. Acquire, according to the channel information, subcarriers with the worst channel condition for each user, for example, (\<k<K) users, and according to the user throughput of the first user and the channel condition being the worst. The subcarrier is allocated to the channel information n _k of the first user, and the first baseline power of the first user is determined _; that is, the first baseline power of each user can be obtained;

Specifically, based on the calculation of the complex amplitude of the first user access to channel conditions in terms of the worst subcarrier, and in accordance with ¾ and _¾ by water-filling algorithm to determine the user of a first baseline power;

The following loop is performed for each unallocated subcarrier:

4003. Obtain subcarriers with optimal channel conditions for each user, for example, (\<k<K) users, according to the channel information, and according to the first user. user throughput, channel conditions of the optimal allocation of subcarriers to the k th user channel information _Lambda, and binding of the subcarrier set assigned user & determining a baseline power _¾ of a second user; that , can get the second baseline power of each user;

Specifically, the sub-carriers with the best channel conditions for the first user are obtained according to the amplitude calculation of the complex number, and the second baseline power p _{k of the} first user is determined according to the union of & and the water injection algorithm. ', _nt ;

4004: Determine a power reduction value of each user; the power reduction value is a difference _Pk , _nt of the first baseline power and the second baseline power;

Expressed as: p =P _k , _n "P 4005. Acquire a maximum power reduction value, including: acquiring, in a case where the number of unallocated subcarriers is greater than the number of users of unassigned subcarriers, obtaining a maximum value of all power reduction values Δ^ as a maximum power reduction value; when unallocated If the number of subcarriers is equal to the number of users of the unassigned subcarriers, for the user whose number of allocated subcarriers is 0, the power reduction value of the user is increased by a preset offset ( ) to obtain a new power reduction value. And obtaining a maximum value of the new power reduction value and other power reduction values as the maximum power reduction value;

This step is formulated as:

m _k - K _E );

Wherein the maximum value of _Δ Α _¾ of _Δ Α _½,, subcarrier allocation to users coming * (i.e., the first user *) is the maximum power reduction power reduction value.

The offset needs to ensure that the new power reduction value of the allocated number of subcarriers is greater than the number of allocated subcarriers other than 0, so that each user can be allocated to the subcarriers.

4006. Determine, according to the maximum power reduction value, a result of the current cycle, and update a system variable related to a result of the current cycle; the current cycle result includes the subcarrier that is allocated in the current cycle, and the subcarrier is allocated to the subcarrier. User;

The result of the current cycle is that the power reduction value of the subcarriers allocated to the user is the maximum power reduction value; and the system variables related to the results of the current cycle are updated:

& * =&*υ{ *};Update User Allocated Subcarrier Collection

Ρ = _Ρ , _Λ ,; update the transmit power p _{k that} assigns subcarriers to the user;

P^ P^; update the user's allocated transmit power set 3⁄4*= _3⁄4 *+1; update the number of subcarriers allocated by the user S = update the unallocated subcarrier set of the system

4007. Determine whether all subcarriers are allocated; if not, continue the loop on the basis of the updated system variable until all subcarriers are allocated; if yes, output the subcarrier set { & } and power Assign the collection { Ρ }.

The judgment in this step can actually determine whether N - is equal to 0.

103. Allocate a subcarrier and a transmit power to the user according to the determined set of subcarriers and the set of power allocations.

The foregoing radio resource allocation method may be applied to a scenario in which an OFDMA downlink system performs radio resource allocation, where the radio resources include: subcarriers and transmit power. The subject of the above steps may be a radio resource allocation device, which may be a functional component of the base station.

Embodiments of the present invention provide a method for allocating radio resources, and determining an optimal throughput rate according to a correspondence between a system throughput rate and an intermediate energy optimal value, and when the system is in an optimal throughput rate, according to a maximum power The subcarrier set determined by the priority algorithm and the power allocation set are reduced, and the radio resources are allocated according to the determined result, so that the downlink OFDMA system can allocate the radio resources according to the energy efficiency optimal scheme. On the other hand, as shown in FIG. 5, an embodiment of the present invention further provides a radio resource allocation apparatus, which may be specifically applied to a downlink OFDMA system. Among them, in the embodiment of the present invention, all systems based on OFDMA technology are called OFDMA systems. For example, the downlink system based on the OFDMA technology may include: a downlink LTE WIMAX (Long Term Evolution - World Wide Interoperability for Microwave Access) system. The radio resource allocation apparatus in this embodiment may be a downlink OFDMA. Base station in the system.

The wireless resource allocation device 50 includes:

The first determining unit 51 is configured to determine an optimal throughput rate of the system according to a correspondence between a system throughput rate and an intermediate energy optimal value;

a second determining unit 52, configured to: when the system is in an optimal throughput rate, determine a set of subcarriers and a power allocation set according to a maximum power reduction priority algorithm;

The allocating unit 53 is configured to allocate a subcarrier and a transmit power to the user according to the determined set of subcarriers and the set of power allocations.

Preferably, the first determining unit 51 includes: determining a minimum subunit, acquiring a sub Unit and determine the optimal subunit.

Determining a minimum subunit for determining a system minimum throughput rate;

The obtaining subunit is configured to obtain a derivative of an energy efficiency intermediate optimal function at a minimum throughput rate of the system; the energy efficiency intermediate optimal function is a system throughput rate, and an energy efficiency intermediate optimal value obtained by an energy efficiency function Correspondence relationship

Preferably, the energy efficiency function is a ratio of a system throughput rate to a total system transmission power, and the total transmission power of the system is a sum of a system transmission power and a system static circuit power.

Each subcarrier is assigned to at most a unique user;

The throughput rate on each subcarrier is non-negative;

The system transmit power is less than or equal to the system transmit power peak; the sum of the user's weight values; the weight value is used to indicate fairness between users;

Preferably, the weight of the user is a product of a difference between a current throughput rate of the system and a minimum throughput rate of the system and a user experience factor of the user; the minimum throughput of the system is a minimum throughput rate of all users. Sum;

The user experience factor of a user is the ratio of the minimum throughput rate of the user divided by the minimum throughput rate of the system; or, the user experience factor of a user is the amount of data in the queue of the user divided by the system. The ratio of the amount of data in the queued queue; the amount of data in the queued queue of the system is the sum of the amount of data in the queued queues of all users.

The determining an optimal subunit is configured to determine an optimal throughput rate of the system according to a quasi-upward characteristic of the energy efficiency intermediate optimal function and a comparison result of the derivative with 0.

Further, the determining the optimal subunit includes:

a first determining module, configured to determine, according to a quasi-convex characteristic of the energy efficiency intermediate optimal function, a system minimum throughput rate of the system when the derivative is less than or equal to 0;

a second determining module, configured to determine, according to the quasi-convex characteristic of the energy efficiency intermediate optimal function, that the derivative power is less than or equal to a peak value of a system transmit power, using a dichotomy method The optimal throughput rate of the system.

Further, the second determining module includes:

Determining a submodule, configured to determine a first boundary value and a second boundary value of the dichotomy when the derivative is greater than 0; wherein, the first boundary value is a system minimum throughput rate, and the second boundary a value of a system throughput rate such that the energy efficiency intermediate optimal function has a derivative of system throughput that is less than zero;

a calculation submodule, configured to obtain an average of the first boundary value and the second boundary value; and in the case of the average, obtain a set of subcarriers and a power allocation set determined by using a maximum power reduction priority algorithm, and calculate the System transmit power;

Determining a loop sub-module, configured to determine whether a transmit power of the system is greater than a peak value of a system transmit power;

If the system transmit power is greater than the system transmit power peak, the first boundary value is unchanged, and the second boundary value is set to the average value, and the calculation module and the judgment loop module are cyclically operated until the obtained system transmit power is less than or Equal to the system transmit power peak;

If the system transmit power is less than or equal to the system transmit power peak, it is determined whether the dichotomy is converged;

If it does not converge, the derivative of the energy efficiency intermediate optimal function to the system throughput rate is obtained at the last mean; in the case where the derivative is less than 0, the first boundary value is unchanged, and the second boundary value is set to the last mean value. And if the derivative is greater than 0, the first boundary value is set to the last average value, and the average of the first boundary value and the second boundary value is rounded to all steps of the step until the dichotomy converges ;

If it converges, it ends and the last average obtained is the optimal throughput of the system. Further, the maximum power reduction priority algorithm utilized in the second determining unit 52 includes:

An initialization subunit, configured to initialize a system variable; the system variables include: a number of users, a user throughput rate per user, a number of subcarriers allocated by each user, a set of subcarriers allocated by each user, and each user The allocated transmit power set, the number of all subcarriers, the unallocated set of subcarriers, the channel information assigned to any user per subcarrier, and the number of users of unassigned subcarriers;

a worst allocation subunit, configured to respectively acquire, according to the channel information, a subcarrier with the worst channel condition for each user, and allocate each subcarrier according to a user throughput rate of each user and a worst condition of the channel condition to each Channel information of each user, determining a first baseline power of each user;

a cyclic subunit, configured to run the following modules for each unallocated subcarrier; the cyclic subunit includes:

An optimal allocation module, configured to: according to the channel information, from an unassigned set of subcarriers Obtaining subcarriers with optimal channel conditions for each user separately, and assigning channel information to each user according to the user throughput rate of each user, the subcarriers optimal for the channel condition, and combined with each user has been allocated a set of subcarriers, determining a second baseline power for each user;

And obtaining a difference module, configured to obtain a power reduction value of each user; the power reduction value is a difference between the first baseline power and the second baseline power;

An obtaining module, configured to obtain a maximum power reduction value, where the acquiring module is configured to obtain a maximum value of all power reduction values as a maximum power reduction value, when the number of unallocated subcarriers is greater than the number of unallocated subcarriers When the number of unallocated subcarriers is equal to the number of users of the unassigned subcarriers, for the user whose number of allocated subcarriers is 0, the power reduction value of the user is increased by a preset offset to obtain new power. Decreasing the value, and obtaining the maximum value of the new power reduction value and the other power reduction value as the maximum power reduction value;

Determining a result module, configured to determine a current cycle result according to the maximum power reduction value, and update a system variable related to a result of the current cycle; the current cycle result includes a subcarrier that is allocated in the current cycle, and the a user to which the subcarrier is allocated; a judgment loop module for judging whether all subcarriers are allocated; if not, continuing the loop on the basis of the updated system variable until all subcarriers are allocated; , then output a set of subcarriers and a set of power allocations. It should be noted that the implementation manners of each unit, each subunit, and each module in the apparatus for allocating radio resources according to the embodiments of the present invention may refer to the foregoing radio resource allocation method. The embodiment of the invention provides a device for allocating radio resources, and determining an optimal throughput rate of the system according to a correspondence between a system throughput rate and an intermediate energy optimal value, and when the system is in an optimal throughput rate, according to the maximum power The subcarrier set determined by the priority algorithm and the power allocation set are reduced, and the radio resources are allocated according to the determined result, so that the downlink OFDMA system can allocate the radio resources according to the energy efficiency optimal scheme. A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to program instructions, and the foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing steps include the steps of the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

Claims

Claim

A radio resource allocation method, comprising:

The subcarriers and the transmit power are allocated to the user in accordance with the determined set of subcarriers and the set of power allocations.

The allocation method according to claim 1, wherein the determining the optimal throughput rate of the system according to the correspondence between the system throughput rate and the intermediate energy optimal value comprises:

Determine the minimum throughput of the system;

Obtaining a derivative of an energy efficiency intermediate optimal function at a minimum throughput rate of the system; the energy efficiency intermediate optimal function is a correspondence between a system throughput rate and an energy efficiency intermediate optimal value obtained by an energy efficiency function;

The optimal throughput rate of the system is determined according to the quasi-convexity characteristic of the energy efficiency intermediate optimal function and the comparison result of the derivative with 0.

The distribution method according to claim 2, wherein the energy efficiency function is a ratio of a system throughput rate to a total system transmission power, and the total transmission power of the system is a sum of a system transmission power and a system static circuit power.

The allocation method according to claim 3, wherein the constraint condition of the energy efficiency intermediate optimal function comprises:

Each subcarrier is assigned to at most a unique user;

The throughput rate on each subcarrier is non-negative;

The system transmit power is less than or equal to the system transmit power peak; the sum of the user's weight values; the weight value is used to indicate fairness between users.

The allocation method according to claim 4, wherein the weight of the user is a product of a difference between a current throughput rate of the system and a minimum throughput rate of the system and a user experience factor of the user; The minimum throughput of the system is the sum of the minimum throughput of all users;

Wherein the user experience factor of a user is the user's minimum throughput rate divided by the user The ratio of the minimum throughput of the system; or, the user experience factor of a user is the ratio of the amount of data in the queue of the user divided by the amount of data in the queued queue of the system; the amount of data in the queued queue of the system The sum of the amount of data in the queued queue for all users.

The distribution method according to any one of claims 2 to 5, wherein the quasi-convex characteristic according to the energy efficiency intermediate optimal function and the comparison result of the derivative and 0 are determined. The optimal throughput of the system includes:

If the derivative is less than or equal to 0, determining an optimal throughput rate of the system according to the quasi-uplifting characteristic of the energy efficiency intermediate optimal function;

If the derivative is greater than 0, the optimal throughput rate of the system is determined by the dichotomy method according to the quasi-convex characteristic of the energy efficiency intermediate optimal function under the premise that the system transmit power is less than or equal to the peak value of the system transmit power.

The distribution method according to claim 6, wherein the quasi-convex characteristic according to the energy efficiency intermediate optimal function uses a dichotomy method under the premise that the system transmit power is less than or equal to the peak value of the system transmit power Determining the optimal throughput of the system includes:

Determining a first boundary value and a second boundary value of the dichotomy; wherein the first boundary value is a system minimum throughput rate, and the second boundary value is a system such that the energy efficiency intermediate optimal function has a derivative of the system throughput rate less than 0 The value of the throughput rate;

Obtaining an average of the first boundary value and the second boundary value;

In the case of the mean, the set of subcarriers and the set of power allocations determined by the maximum power reduction prior algorithm are obtained, and the transmit power of the system is calculated;

Determining whether the system transmit power is greater than a system transmit power peak;

If the system transmit power is greater than the system transmit power peak, the first boundary value is unchanged, and the second boundary value is set to the average value, and the average of the first boundary value and the second boundary value is obtained by looping to the step All steps until the resulting system transmit power is less than or equal to the system transmit power peak;

If it does not converge, the derivative of the energy efficiency intermediate optimal function to the system throughput rate is obtained at the last mean; in the case where the derivative is less than 0, the first boundary value is unchanged, and the second boundary value is set to the last mean value. And if the derivative is greater than 0, the first boundary value is set to the last average value, and the average of the first boundary value and the second boundary value is rounded to all steps of the step until the dichotomy converges ; If it converges, it ends and the last average obtained is the optimal throughput of the system.

The allocation method according to any one of claims 1 to 5, wherein the maximum power reduction priority algorithm comprises:

Initializing system variables; the system variables include: number of users, user throughput per user, number of subcarriers allocated per user, set of subcarriers allocated by each user, and set of transmit power allocated by each user The number of all subcarriers, the unassigned set of subcarriers, the channel information allocated to any user for each subcarrier, and the number of users of the unassigned subcarriers; respectively, according to the channel information, acquiring channels for each user The sub-carrier with the worst condition, and determining the first baseline power of each user according to the user throughput rate of each user and the channel information of the sub-carrier with the worst channel condition assigned to each user;

The following loop is performed for each unallocated subcarrier:

Obtaining, according to the channel information, a subcarrier that has the best channel condition for each user from the unallocated subcarrier set, and assigning the subcarrier according to the user throughput rate of each user and the channel condition optimal to Determining a second baseline power of each user by using channel information of each user and combining a set of subcarriers allocated by each user;

Obtaining a power reduction value of each user; the power reduction value is a difference between the first baseline power and the second baseline power;

Obtaining a maximum power reduction value, including: obtaining a maximum value of all power reduction values as a maximum power reduction value when the number of unallocated subcarriers is greater than a number of users of unassigned subcarriers; when the number of unallocated subcarriers is If the number of users that are not allocated subcarriers is equal to 0, the user whose power consumption is 0 is increased by a preset offset amount to obtain a new power reduction value, and the new power reduction is obtained. The maximum value of the value and other power reduction values is taken as the maximum power reduction value;

Determining the current loop result according to the maximum power reduction value, and updating a system variable related to the current loop result; the current loop result includes the subcarrier that is allocated in the current loop, and the user to which the subcarrier is allocated ;

It is judged whether all subcarriers are allocated; if not, the above loop is continued on the basis of the updated system variables until all subcarriers are allocated; if yes, the subcarrier set and the power allocation set are output.

A radio resource allocation apparatus, comprising:

a first determining unit, configured to determine an optimal throughput rate of the system according to a correspondence between a system throughput rate and an intermediate energy optimal value; a second determining unit, configured to determine, according to a maximum power reduction priority algorithm, a set of subcarriers and a power allocation set when the system is in an optimal throughput rate;

And an allocating unit, configured to allocate a subcarrier and a transmit power to the user according to the determined set of subcarriers and the set of power allocations.

The distribution device according to claim 8, wherein the first determining unit comprises:

Determining the smallest subunit for determining the minimum throughput of the system;

Obtaining a subunit, configured to obtain a derivative of an energy efficiency intermediate optimal function at a minimum throughput rate of the system; the energy efficiency intermediate optimal function is a correspondence between a system throughput rate and an energy efficiency intermediate optimal value obtained by an energy efficiency function ;

Determining an optimal subunit for determining a system optimal throughput rate according to a quasi-upward characteristic of the energy efficiency intermediate optimal function and a comparison result of the derivative with zero.

1 1. The distribution device according to claim 10, wherein the energy efficiency function is a ratio of a system throughput rate to a total system transmission power, and the total transmission power of the system is a sum of a system transmission power and a system static circuit power. .

12. The distribution device according to claim 11, wherein the constraint condition of the energy efficiency intermediate optimal function comprises:

Each subcarrier is assigned to at most a unique user;

The throughput rate on each subcarrier is non-negative;

The distribution device according to claim 12, wherein the weight value of the user is a product of a difference between a current throughput rate of the system and a minimum throughput rate of the system and a user experience factor of the user; The minimum throughput of the system is the sum of the minimum throughput of all users;

The distribution device according to any one of claims 10 to 13, wherein the determining the optimal subunit comprises: a first determining module, configured to determine, according to the quasi-convex characteristic of the energy efficiency intermediate optimal function, that the system optimal throughput is the minimum throughput rate of the system, if the derivative is less than or equal to 0;

The distribution device according to claim 14, wherein the second determining module comprises:

Determining a submodule, configured to determine a first boundary value and a second boundary value of the dichotomy when the derivative is greater than 0; wherein, the first boundary value is a system minimum throughput rate, and the second boundary value is such that The value of a system throughput rate in which the energy efficiency intermediate optimal function has a derivative of system throughput of less than zero;

If it converges, it ends and the last average obtained is the optimal throughput of the system.

The distribution device according to any one of claims 9 to 13, wherein the maximum power reduction priority algorithm comprises:

An initialization subunit, configured to initialize a system variable; the system variables include: a number of users, a user throughput rate per user, a number of subcarriers allocated by each user, and each user has The set of allocated subcarriers, the set of transmit power allocated by each user, the number of all subcarriers, the set of unallocated subcarriers, the channel information assigned to any user by each subcarrier, and the number of users of unassigned subcarriers;

An optimal allocation module, configured to acquire, according to the channel information, a subcarrier that has an optimal channel condition for each user from an unassigned set of subcarriers, and according to a user throughput rate of each user, the channel condition Determining the subcarriers of each user to the channel information of each user, and combining the set of subcarriers allocated by each user, determining the second baseline power of each user;

Determining a result module, configured to determine a current cycle result according to the maximum power reduction value, and update a system variable related to a result of the current cycle; the current cycle result includes a subcarrier that is allocated in the current cycle, and the The user to which the subcarrier is assigned;

a judging loop module, configured to determine whether all subcarriers are allocated; if not, continuing the loop on the basis of the updated system variable until all subcarriers are allocated; if yes, outputting the subcarrier set and Power allocation set.