WO2013149439A1

WO2013149439A1 - Power allocation method and communication node

Info

Publication number: WO2013149439A1
Application number: PCT/CN2012/077873
Authority: WO
Inventors: 朱登魁; 宁迪浩; 肖华华; 李子荣; 鲁照华
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-04-06
Filing date: 2012-06-29
Publication date: 2013-10-10
Also published as: CN103369657B; CN103369657A

Abstract

A power allocation method and a communication node. The method comprises: a communication node configuring N antennas, and each antenna simultaneously transmitting K data streams; the communication node allocating a power P_nk to the kth data stream on the nth antenna according to the following conditions: the sum of the allocated powers of the K data streams on the nth antenna is not more than the maximum transmitting power Q_n of the antenna; the sum of the allocated power of the kth data stream on the N antennas is not more than the power G_k of the kth data stream, where G_k is the power allocated in advance by the communication node to the kth data stream on a current resource block. The method can be applied to optimally allocate the power of each data stream when the antenna power is limited, thereby increasing the system performance.

Description

Power distribution method and communication node

Technical field

The present invention relates to the field of wireless communications, and in particular to a power distribution method and a communication node in which a control node simultaneously transmits a plurality of data streams.

Background technique

MIMO (multiple input multiple output) technology is a major breakthrough in smart antenna technology in the field of wireless mobile communications. The technology can multiply the capacity and spectrum utilization of the communication system without increasing the bandwidth; multipath can be used to mitigate multipath fading; and the common channel interference can be effectively eliminated, the channel reliability can be improved, and the error can be reduced. Bit rate is a key technology that must be used in a new generation of mobile communication systems.

Multi-antenna technology has evolved from traditional point-to-point communication (Single User MIMO (SU-MIMO)) to point-to-multipoint communication (Multi-User MIMO (MU-MIMO)) Whether in point-to-point or point-to-multipoint communication, there is a control node that simultaneously transmits multiple data streams to one terminal or multiple terminals. In this communication, the control node first calculates a precoding matrix for each data stream by a precoding operation (where the control node calculates the channel coefficients corresponding to the data stream and corresponding optimization criteria), and corresponds each data stream. The data is formed for the data transmitted on each antenna, so that the data transmitted on each antenna is a superposition of the data formed by the multiple data streams, which requires the control node to have a limited power on each antenna. Several data streams are allocated. In the traditional power allocation analysis, it is assumed that the total power of the control node is limited, instead of each antenna power being separately limited, so its power allocation is often in accordance with each of the precoding vectors. The ratio of the square of the absolute value of the element is allocated. In fact, due to the cost, the control node is often one power amplifier per antenna, that is, the transmission power of each antenna is individually limited, which gives the power distribution band. A certain complexity is coming, especially in the case of multiple data streams, which must satisfy the amplitude ratio between the precoding vector coefficients. Consider the power constraints on each antenna, and also consider the power allocation problem between data streams. For this type of problem, a common method is to use the optimization algorithm for global optimization, but this will bring two Trouble: First, the problem does not necessarily have an optimal solution, second, even if there is an optimal solution, Iterative solution is needed to solve the complexity, especially when the number of antenna data streams is large. Summary of the invention

The technical problem to be solved by the embodiments of the present invention is to provide a power allocation method and a communication node, so that the power of each data stream is optimally allocated when the antenna power is limited, thereby improving systemicity.

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dagger.

In order to solve the above technical problem, an embodiment of the present invention provides a power allocation method, including: configuring a N antenna by a communication node, and transmitting f data streams simultaneously on each antenna;

The communication node allocates power _Pnk to the A data stream on the /th antenna according to the following conditions _:

The sum of the powers allocated by the data streams on the "antenna" does not exceed the maximum transmit power of the antenna a;

The sum of the powers allocated by the kth data stream on the N antennas does not exceed the power of the kth data stream;

Wherein, the communication node is pre-assigned to the power of the A data stream on the current resource block; N, f are all natural numbers, and N is greater than or equal to 2, f is less than or equal to N; n = \, - -, N; k = \ , K.

The foregoing method further has the following features: the resource block includes one or more of the following: one subcarrier in an Orthogonal Frequency Division Multiplexing (OFDM) technology system;

One subcarrier in an orthogonal frequency division multiple access system;

Multiple subcarriers on the same OFDM signal symbol;

Time domain multiple orthogonal frequency division multiplexing (OFDM) technology symbol blocks formed by multiple subcarriers in the frequency domain. The above method also has the following features: The communication node allocates power /^ including:

The communication node adaptively allocates power _Pnk according to channel state information of each data stream. The above method also has the following features: The adaptive allocation of power by the communication node comprises: constructing the following system of equations according to the power of each data stream and the transmission power of each antenna to obtain all possible power allocation schemes: k=\ ,

Construct a matrix equation by selecting any N + -1 equations from the system of equations:

[A b] 0, where

A is a coefficient matrix,

b = [ ^G i ■■■ ^G Kl Ov],

Calculate the coefficient matrix A = [A b]

Calculate the power scale factor on each antenna

Where f = [ _r ^r — ΐ] ^Γ , r = [r _u ... r _m r _u ... r _N2 ... r _XK ... r _NK ,

P = [Pn ■■■ Pm Pn ... PN2 ... Ρικ ... PN ^ contains N*f elements; r _nk is the precoding vector corresponding to the kth data stream on the nth antenna; where n = \,-- -,N,k = \,--;K;

Allocate power.

In order to solve the above problem, an embodiment of the present invention further provides a communication node, including: a configuration module, configured to configure N antennas, and simultaneously transmit f data streams on each antenna;

An allocation module configured to allocate power to the A data stream on the "antennas", wherein the following constraints are met:

The sum of the powers of the kth data stream allocated on the N antennas does not exceed the work of the kth data stream. Rate

Wherein, the communication node is pre-allocated to the power of the kth data stream on the current resource block; N, f are all natural numbers, and N is greater than or equal to 2, f is less than or equal to N; n = \, --, N; k = \ , K.

The foregoing communication node further has the following features: the resource block includes one or more of the following: one subcarrier in an Orthogonal Frequency Division Multiplexing (OFDM) technology system;

One subcarrier in an orthogonal frequency division multiple access system;

Multiple subcarriers on the same OFDM signal symbol;

Time domain multiple orthogonal frequency division multiplexing (OFDM) technology symbol blocks formed by multiple subcarriers in the frequency domain. The above communication node also has the following features:

The configuration module is configured to adaptively allocate power according to channel state information of each data stream.

The above communication node also has the following features:

The configuration module includes:

A first unit disposed in the stream of power G _k and transmission power of each antenna configuration is obtained based on each data to all possible power allocation scheme:

κ

a two unit configured to select an arbitrary N + -l equation construction matrix according to the system of equations

0, where,

A is a coefficient matrix,

b ⁼ [ ^G i ·" Ov],

The third unit, which is set to calculate the coefficient matrix =^ b], calculates the power scale factor β and the sum of the guaranteed antennas: Ρ = Ι - Α ^Γ (ΑΑ ^Γ ) ^_1 ) f , where f = [r ^r - 1] ^Γ , r = [r ... r _m r _u ... r _N2 ... r _XK ... r _NK ,

P = [Pn ■■■ Pm Pn ... PN2 ... Ρικ ... PN ^ contains N* elements; r _nk = , is the precoding vector corresponding to the kth data stream on the _nth antenna; P _nk = ∑Q _n , n = \,-,N,k = \,-,K - and

∑∑P _nl

n=\ l=\

The fourth unit, which is set to distribute power.

In summary, the power allocation method and the communication node provided by the embodiments of the present invention can optimally allocate the power of each data stream when the antenna power is limited, thereby improving system performance. BRIEF abstract

1 is a flowchart of a power allocation method according to an embodiment of the present invention;

2 is a schematic diagram of a communication node according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a configuration module according to an embodiment of the present invention. Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

FIG. 1 is a flowchart of a power allocation method according to an embodiment of the present invention. As shown in FIG. 1, the method in this embodiment includes the following steps:

S10. The communication node is configured with N antennas, and f data streams are simultaneously transmitted on each antenna;

S20. The communication node allocates power _Pnk to the A data stream on the “first antenna.” In the wireless communication system link, the control node allocates power on each antenna to a given resource according to the following conditions. Multiple data streams transmitted simultaneously:

The communication node is configured with N (where N is a natural number and greater than or equal to 2) transmit antennas, and each antenna simultaneously transmits f data streams, and the control node is on the antenna (( η = \,····Ν) Give the first A ( Α = 1,···, , less than or equal to N) The power allocated by the data stream is P _nk = \,''',K, _n = \,-,N )„ where p _nk satisfies the following constraints :

Is a real number greater than 0, and ^: in the first data stream "(w = .., N) antennas are allocated power does not exceed the maximum transmit power of the antenna _A,)

The sum of the powers allocated by the data streams on the N antennas does not exceed the power of the A-th data stream, ie

N

T, Pnk ^≤ G _k ;

n=\

Wherein, 3⁄4 indicates the power that the communication node pre-allocates to the (k = l, -, K) data on the current resource block.

The current resource block may be a subcarrier in an OFDM (Orthogonal Frequency Division Multiplexing) system or an OFDMA (Orthogonal Frequency Division Multiple Access) system, or It is a plurality of subcarriers on the same OFDM symbol, or a resource block composed of a plurality of subcarriers in the frequency domain of a plurality of OFDM symbols in the time domain. Of course, it can also be a resource unit (frequency domain subcarrier or time domain symbol) in other wireless systems.

Preferably, the communication node adaptively allocates power according to channel state information of each data stream.

Wherein the adaptively allocated power comprises: the communication node uses the power constraint of each data stream and the transmit power constraint of each antenna to obtain all possible power allocation schemes, all possible power allocation schemes form a subspace, and then A desired power allocation vector for each data stream on each antenna is projected into said subspace to find a final power allocation scheme;

The calculation method of the power allocation scheme is:

The subspace formed by all the solutions of the system of equations is recorded as all possible power allocation schemes;

Selecting any + -1 equations from all the above equations will remove all coefficients except p _nk Write the coefficient matrix A as follows:

Write each coefficient except the unknown number into a row in the matrix, which is formed in total.

N + rows, each row containing a service + 1 element, the element A ( ) at the _/· column position of the first row of the above matrix belongs to the set {Ο,Ι,-Ι, ,···, ^,-^...- ^,^..., ; or write the coefficients of each equation except the unknowns into a column in the matrix, which is formed in total.

N + column, each column contains a service + 1 element, the element of the first row of the above matrix

-( ··, -(3⁄4 ; The operation of projecting the expected power vector into the solution subspace of the equation is:

ρ = (ΐ-Α ^Γ (ΑΑ ^Γ ) ^_1 Α)? , β is the power scale factor on each antenna;

Where f = [r ^T aj a is an arbitrary real number;

^Γ ~ [^11 ... ^R N\ ^R \2 ... ^R N2 ... ^R \K ... ^R NK ] r is the expected power allocation vector of all data streams on all antennas, the specific value of which is determined by the control node according to the corresponding channel coefficients of the data stream Obtaining, for example, the square of the magnitude of the coefficient of the precoding vector corresponding to the data stream, ie

Rnk is the expected power allocation vector of the first data stream on the "one antenna".

Ρ = [Αι ... Pm Pn ■■■ PN2 ■■■ Ρικ ... ΡΝΚΪ ^ β contains N*f elements;

a precoding vector corresponding to the kth data stream on the nth antenna;

Where ρ represents the power allocated by the first "data stream" on the first antenna;

The communication node allocates power. Through the power allocation scheme of the embodiment of the present invention, on the one hand, the power of the control node is maximized, and the almost optimal allocation under the condition of limited line power per day improves the power in the useful direction. The utilization rate ultimately improves the spectral efficiency of the system, and the calculation is very simple and easy to implement.

Example 1

In this embodiment, the communication node is set to have four transmit antennas, and the maximum transmit power of each antenna is ρ, that is, Q = ρ ₂ = _3⁄4 = ρ ₄ = ρ, so that each antenna transmits two different simultaneously. The data stream, and the power allocated to each data stream by the pre-allocation method is equal, that is, the pre-coding vectors corresponding to the two data streams are:

Then use the power allocation scheme of the scheme to allocate power as follows: Obviously, the power allocation of each data stream on each antenna can be obtained by the following equation k=\

∑ _Pnk =G,k = l,-,2

n=\ arbitrarily select 5 of them, construct the constraint matrix equation [A b] =0, where each matrix is:

b = [G Q Q Q

Calculate the coefficient matrix: 1 1 1 1 0 0 0 0 G

1 0 0 0 1 0 0 0 Q

A = [A b]: 0 1 0 0 0 1 0 0 Q

0 0 1 0 0 0 1 0 Q

0 0 0 1 0 0 0 1 Q

To the subspace of the solution of the power constraint equation, the method is as follows

Where i = [r ^r - 1] ^Γ , r = [r _n r _2X r _3l r _4X r _n r ₂₂ r ₃₂ r ₄₂ f ,

3- r _nk

= ---, 2, which is the square of the absolute value of each element of the precoding vector.

The power allocation vector is then scaled such that the sum of all allocated powers equals the sum of all antenna powers of the control nodes:

Ρ*= Q _n ,n = l,-,N,k = l,.:,K;

Wherein, represents the power allocated by the "data stream" on the A-th antenna.

Ρ = [Α,···,Α], the / ( / = 1,···,8 ) elements in the vector represent the third = / mod2 ) The data stream is at the Mth ( n = l - 4k The allocated power on the antenna.

Example 2

In this embodiment, the communication node is set to have four transmit antennas, and the maximum transmit power of each antenna is β, that is, β = β ₂ = β ₃ = β ₄ = β, so that each antenna transmits two simultaneously. Different data streams, and the power allocated to each data stream by the pre-allocation method is equal, that is, the pre-coding vectors corresponding to the two data streams are:

w, = , w _2l w ₃₁ w ₄₁ f and w ₂ = [w ₁₂ w ₂₂ w ₂ wj , then the power allocation scheme using the scheme of the scheme is as follows: Obviously the power allocation of each data stream on each antenna should be By the equation below ∑ _Pnk = Q, n = l, -, 4

k=\

4

Arbitrarily select five of them, construct a constraint matrix equation [x ^: 0, where each moment

The arrays are:

0 0 0 0 1 1 1

0 0 0 1 0 0 0

A = 0 0 1 0 0 0 1

0 1 0 0 0 1 0 b = [G Q Q Q

Calculate the coefficient matrix:

Then project the desired power distribution into the subspace of the power constraint equation solution, as follows

p = (IA(A ^J A) A ^r f where 1] , ^Γ = [^41 ^r 3 ^r 2 ^r u ^r A2 3⁄4 3⁄4 3⁄4 ] and ^r _nk = W

Nk n = \,---,4,k = \,---,2, which is the square of the absolute value of each element of the precoding vector.

The power allocation vector is then scaled such that the sum of all allocated powers is equal to the sum of all antenna powers of the control node: P _nk = _N ∑Q _n , n = U,k = , K

∑∑p _nl

n=\ l=\

Where ρ represents the power allocated by the "data stream" on the A-th antenna. Embodiment 3

In this embodiment, the setting communication node has N transmitting antennas, and the maximum transmitting power of each antenna is respectively

Let each antenna transmit ^: different data streams at the same time, and the power allocated to each data stream by pre-allocation method is (3⁄4, Α = 1,···, and pre-coding corresponding to f data streams) The vectors are:

Wm] , k = \,---,K ,

Then use the power allocation scheme of the scheme to allocate power as follows: The power allocation of each data stream on each antenna should be determined by the following equation

Select the former N + -l equations and construct the constraint matrix equation [A b] =0, where each matrix is

b = [^ Q _N ]

Calculating the coefficient matrix A = [A b] , then projecting the desired power distribution into the subspace of the power constraint equation solution, as follows Ρ = Ι-Α ^Γ (ΑΑ ^Γ ) ^_1 )f where f = [r ^r - 1] ^Γ , r = [r ... r _m r _u ... r _N2 ... r _XK ... r _NK , and ^=| ^ ² , "=1, -, ^=1, one, is the square of the absolute value of each element of the precoding vector.

The power allocation vector is then scaled such that the sum of all allocated powers is equal to the sum of all antenna powers of the control node:

Ρ*= Ν κ ∑Q _n ,n = l,-,N,k = l,.:,K;

ρP _nl, where ρ represents the power allocated by the first data stream on the A antenna. FIG. 2 is a schematic diagram of a communication node according to an embodiment of the present invention. As shown in FIG. 2, the communication node of this embodiment includes:

a configuration module, configured to configure N antennas, and transmit f data streams simultaneously on each antenna; an allocation module configured to allocate power to the A data stream on the “antennas”, wherein the following constraints are met : the sum of the powers allocated by the data streams on the "antennas" does not exceed the maximum transmit power of the antennas; the sum of the powers of the kth data streams allocated on the N antennas does not exceed the kth data stream Power

Wherein, the communication node is pre-allocated to the power of the kth data stream on the current resource block; N is a natural number, and is greater than or equal to 2; ^: less than or equal to N; n = l, -, N; k = \, K. The resource block includes one or more of the following:

One subcarrier in the Orthogonal Frequency Division Multiplexing (OFDM) technology system;

One subcarrier in an orthogonal frequency division multiple access system;

Multiple subcarriers on the same OFDM signal symbol;

Time domain multiple orthogonal frequency division multiplexing (OFDM) technology symbol blocks formed by multiple subcarriers in the frequency domain. The configuration module is adaptively allocated according to channel state information of each data stream. Powerful.

As shown in FIG. 3, the configuration module may include:

A first unit, which is configured to construct a set of metrics according to the power year G _{k of} each data stream and the transmit power of each antenna to obtain all possible power allocation schemes:

0, where,

A is a coefficient matrix,

,

The third unit, which is set to calculate the coefficient matrix =^ b], calculates the power scale factor β and the sum of the guaranteed antennas:

p= IA ^r (AA ^r ) Alf :

Where ρ represents the power allocated by the "data stream" on the A-th antenna ₍

The fourth unit, which is set to distribute power.

One of ordinary skill in the art can understand that all or part of the above steps can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium, such as read only. Memory, disk or disc, etc. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware, or may be implemented in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above is only a preferred embodiment of the present invention, and of course, the present invention may be embodied in various other embodiments without departing from the spirit and scope of the invention. Corresponding changes and modifications are intended to be included within the scope of the appended claims.

Industrial Applicability The power allocation method and communication node of the embodiments of the present invention can optimally allocate the power of each data stream when the antenna power is limited, thereby improving system performance.

Claims

Claim

1. A power distribution method, comprising:

The communication node configures N antennas, and f data streams are simultaneously transmitted on each antenna; and the communication node allocates power to the Ath data stream on the /th antenna according to the following conditions;

The sum of the powers allocated by the f data streams on the "ant antennas" does not exceed the maximum transmit power of the nth antennas; the second data stream is on the N antennas The sum of the allocated powers does not exceed the power of the Ath data stream;

Wherein, the communication node is pre-allocated to the power of the A-th data stream on the current resource block; N, f are all natural numbers, and N is greater than or equal to 2, f is less than or equal to N; n = \, - -, N ; k = \,- --, K.

2. The method of claim 1, wherein: the resource block comprises one or more of the following: one subcarrier in an Orthogonal Frequency Division Multiplexing (OFDM) technology system;

One subcarrier in an orthogonal frequency division multiple access system;

Multiple subcarriers on the same OFDM signal symbol;

Time domain multiple orthogonal frequency division multiplexing (OFDM) technology symbol blocks formed by multiple subcarriers in the frequency domain.

3. The method according to claim 1 or 2, wherein: the step of allocating power by the communication node comprises:

The communication node adaptively allocates power according to channel state information of each data stream.

4. The method of claim 3 wherein: the step of adaptively allocating power by the communication node comprises:

The following equations are constructed based on the power of each data stream and the transmit power of each antenna to obtain all possible power allocation schemes: k=\ ,

[A b] 0, where

A is a coefficient matrix,

b = [ ^G i ■■■ ^G Kl Ov],

Calculate the coefficient matrix A = [A b]

Calculate the power scale factor on each antenna

P = [Pn ■■■ Pm Pn ... PN2 ... Ρικ ... ΡΝΚΪ ^ β contains N* elements; r _nk wn„k is the precoding vector corresponding to the kth data stream on the nth antenna;

N

Nk

p, N K , where n = \,'",N,k = \,'",K

7 n=\

∑∑P _n

n=\ l=\

Allocate power.

5. A communication node, comprising:

a configuration module, configured to: configure N antennas, and transmit f data streams simultaneously on each antenna;

An allocation module, configured to: allocate power to the A data stream on the "antennas", wherein ρ satisfies the following constraints: sum of powers of the f data streams allocated on the "ant antennas" Not exceeding a maximum transmission power ρ of the nth antenna; a sum of powers allocated by the second data stream on the N antennas does not exceed the first A The power of the data stream;

Wherein, the communication node is pre-allocated to the power of the kth data stream on the current resource block; N, f are all natural numbers, and N is greater than or equal to 2, f is less than or equal to N; n = \, --, N; k = \, ---, K.

6. The communication node according to claim 5, wherein the resource block comprises one or more of the following:

One subcarrier in an orthogonal frequency division multiple access system;

Multiple subcarriers on the same OFDM signal symbol;

7. The communication node according to claim 5 or 6, wherein

8. The communication node according to claim 7, wherein the configuration module comprises: a first unit configured to: according to the power of each data stream and the transmit power of each antenna to all possible power allocation schemes: a second unit, which is arranged to select any one of the groups of equations

N + -l equations to construct a matrix equation:

[A b] 0, where

A is a coefficient matrix,

b = [^ ... G _K _, Q ... Q _N ],

x = n ... Pm Pu ... PNI ... Ρικ ... Γ _;

The third unit, which is set to calculate the coefficient matrix = ^ b], calculates the power scale factor β and the sum of the guaranteed antennas: Ρ = Ι - Α ^Γ (ΑΑ ^Γ ) ^_1 ) f , where f = [r ^r - 1] ^Γ , r = [r _u ... r _m r _u ... r _N2 ... r _XK ... r _NK ,

P = [Pn ■■■ Pm Pn ... PN2 ... Ρικ ... ΡΝΚΪ ^ β contains N* elements;

, a precoding vector corresponding to the kth data stream on the nth antenna;

P _nk = ∑Q _n , n = \,-,N,k = \,-,K- and

第四P _nl fourth unit, which is set to distribute power.