CN102316570B - Signal sending method, device and system in relay system - Google Patents

Abstract

The embodiment of the invention discloses a signal sending method, a device and a system in a relay system, wherein the method comprises the following implementation steps of: determining the sending power of each relay node at the maximum total signal-to-noise ratio of the relay system according to the total sending power of all relay nodes between a source end and a target end in the relay system and the sending power of the source end; sending the sending power of the respective relay node to all relay nodes; or sending the sending power of the respective relay node in partial relay nodes to the partial relay nodes in all of the relay nodes, wherein the sending power of the partial relay nodes is greater than zero. The optimization configuration of the relay node power is realized through obtaining the sending power of the relay node at the maximum signal-to-noise ratio of the relay system, and the performance of the relay system is improved.

Description

The sending method of signal, device and system in relay system

Technical field

The present invention relates to communication technical field, particularly sending method, device and the system of signal in a kind of relay system.

Background technology

Among cordless communication network, by via node, assist to send not only and can reduce system transmission path loss, and can improve the throughput of whole system.This is just greatly improved the performance of whole system.The research of transmitting relevant for via node assistance is very significant for the research of future broadband wireless communication systems.The transmission policy that has at present multiple via node, for example, amplify and send (Amplify-and-Forward, AF) and decoding transmission (Decode-and-forward, DF) (or claiming decoding to send), part DF etc.

In the situation that system power is limited, the power division between a plurality of via nodes that simultaneously transmit is larger on the impact of systematic function.Just in double bounce relay cooperative system, by adopting a plurality of via nodes to reach space diversity, the scheme that improves the performance of system describes below.This system comprises: a source s, and a destination d, and m via node 1,2 ..., m.Source communicates with destination under the assistance of via node, and transmission channel adopts time-division quadrature, and each node distributes in (m+1) individual time slot.Meanwhile, suppose for multi-subscriber dispatching and can obtain channel condition information (Channel-State-Information, CSI) completely at base station end.

In the process of transmission, all via nodes are all participated in cooperation, trunking scheme is AF, whole transmitting procedure is divided into m+1 time slot: first time slot, and source is to destination and m via node broadcast singal, and m via node receives after the signal that source sends, be normalized to the received signal, in an ensuing m time slot, m via node arrives destination with identical power delivery again by the signal after normalization successively, and destination merges to received signal again.Wherein, source adopts direct link to be connected with destination, adopts broadcasting link to be connected with via node, and via node adopts multiple access access to link with destination.

Inventor finds in realizing process of the present invention: in whole transmitting procedure, all via nodes are used identical transmitted power to limit systematic function.

Summary of the invention

The embodiment of the present invention provides sending method, device and the system of signal in a kind of relay system.

In relay system provided by the present invention, the sending method embodiment of signal can be achieved through the following technical solutions:

According to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, determine the transmitted power of each via node when the total signal to noise ratio of described relay system maximizes;

To all via nodes, send the transmitted power of via node separately; Or, to part via node in described all via nodes, sending in described part via node the transmitted power of via node separately, the transmitted power of described part via node is greater than zero;

Wherein, described according to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, determine that the transmitted power of each via node when the total signal to noise ratio of described relay system maximizes comprises:

The transmitted power poor, via node that the total transmitted power that maximizes all via nodes between source and destination in the second-order condition, relay system of satisfied convex function according to the total signal to noise ratio of relay system is less than or equal to the transmitted power of relay system gross power and source is more than or equal to zero and be less than or equal to the satisfied linear conditions of maximum transmit power of this via node, the method that adopts protruding optimization, solves $\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\min \left\{\max \right\{0,\sqrt{\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{v^{*}{b}_i}}-\frac{E_s{a}_i+1}{b_i}\},E_{i\max }\}=E-E_s$ In variable v ^*obtain the power of via node transmission source end signal, determine the transmitted power of each via node when the total signal to noise ratio of relay system maximizes;

Wherein, E _sthe transmitted power that represents source, E represents total transmitted power of relay system;

it is the transmitted power sum of all via nodes; H wherein _s,irepresent that source is to the channel gain of i via node,

h _i,drepresent that i via node is to the channel gain of destination,

e _imaxthe upper bound that represents i via node transmitted power; N0 is noise power.

A sending method for signal in relay system, comprising:

Via node obtains the transmitted power of source;

Described via node is according to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, determine when the total signal to noise ratio of relay system maximizes described in the transmitted power of via node;

Described via node according to the transmitted power of described via node to destination transmitted signal;

Wherein, described via node is according to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, determine when the total signal to noise ratio of relay system maximizes described in the transmitted power of via node comprise:

The transmitted power poor, via node that the total transmitted power that maximizes all via nodes between source and destination in the second-order condition, relay system of satisfied convex function according to the total signal to noise ratio of relay system is less than or equal to the transmitted power of relay system gross power and source is more than or equal to zero and be less than or equal to the satisfied linear conditions of maximum transmit power of this via node, the method that adopts protruding optimization, solves $\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\min \left\{\max \right\{0,\sqrt{\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{v^{*}{b}_i}}-\frac{E_s{a}_i+1}{b_i}\},E_{i\max }\}=E-E_s$ In variable v ^*obtain the power of via node transmission source end signal, determine the transmitted power of each via node when the total signal to noise ratio of relay system maximizes;

Wherein, E _sthe transmitted power that represents source, E represents total transmitted power of relay system;

it is the transmitted power sum of all via nodes; H wherein _s,irepresent that source is to the channel gain of i via node,

h _i,drepresent that i via node is to the channel gain of destination,

e _imaxthe upper bound that represents i via node transmitted power; N0 is noise power.

A dispensing device for signal in relay system, comprising:

Power determining unit, for according to total transmitted power of all via nodes between relay system source and destination and the transmitted power of described source, determines the transmitted power of each via node when the total signal to noise ratio of described relay system maximizes;

Power transmitting element, for sending the transmitted power of via node separately to all via nodes; Or, to part via node in described all via nodes, sending in described part via node the transmitted power of via node separately, the transmitted power of described part via node is greater than zero;

Wherein, described power determining unit specifically for, the transmitted power poor, via node that the total transmitted power that maximizes all via nodes between source and destination in the second-order condition, relay system of satisfied convex function according to the total signal to noise ratio of relay system is less than or equal to the transmitted power of relay system gross power and source is more than or equal to zero and be less than or equal to the satisfied linear conditions of maximum transmit power of this via node, the method that adopts protruding optimization, solves $\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\min \left\{\max \right\{0,\sqrt{\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{v^{*}{b}_i}}-\frac{E_s{a}_i+1}{b_i}\},E_{i\max }\}=E-E_s$ In variable v ^*obtain the power of via node transmission source end signal, determine the transmitted power of each via node when the total signal to noise ratio of relay system maximizes;

Wherein, E _sthe transmitted power that represents source, E represents total transmitted power of relay system;

it is the transmitted power sum of all via nodes; H wherein _s,irepresent that source is to the channel gain of i via node, h _i,drepresent that i via node is to the channel gain of destination,

e _imaxthe upper bound that represents i via node transmitted power; N0 is noise power.

, comprising:

Power acquiring unit, for obtaining the transmitted power of source;

Transmitted power determining unit, when determining that according to the transmitted power of total transmitted power of all via nodes between relay system source and destination and source the total signal to noise ratio of relay system maximizes described in the transmitted power of via node;

Signal transmitting unit, sends signal for the transmitted power according to described via node to destination;

Wherein, described transmitted power determining unit specifically for, the transmitted power poor, via node that the total transmitted power that maximizes all via nodes between source and destination in the second-order condition, relay system of satisfied convex function according to the total signal to noise ratio of relay system is less than or equal to the transmitted power of relay system gross power and source is more than or equal to zero and be less than or equal to the satisfied linear conditions of maximum transmit power of this via node, the method that adopts protruding optimization, solves $\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\min \left\{\max \right\{0,\sqrt{\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{v^{*}{b}_i}}-\frac{E_s{a}_i+1}{b_i}\},E_{i\max }\}=E-E_s$ In variable v ^*obtain the power of via node transmission source end signal, determine the transmitted power of each via node when the total signal to noise ratio of relay system maximizes;

Wherein, E _sthe transmitted power that represents source, E represents total transmitted power of relay system;

it is the transmitted power sum of all via nodes; H wherein _s,irepresent that source is to the channel gain of i via node,

h _i,drepresent that i via node is to the channel gain of destination,

e _imaxthe upper bound that represents i via node transmitted power; N0 is noise power.

The transmitting system of signal in a kind of relay system, source, destination and via node, described via node is the trunking in the embodiment of the present invention, or, described source for the embodiment of the present invention provide device, or, also comprise: third party device, the device that the described third party device embodiment of the present invention provides.

Technique scheme has following beneficial effect: the transmitted power of via node while maximizing by obtaining the total signal to noise ratio of relay system, realize distributing rationally of via node power, and promote relay system performance.

Accompanying drawing explanation

In order to be illustrated more clearly in the technical scheme in the embodiment of the present invention, below the accompanying drawing of required use during embodiment is described is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.

Fig. 1 is embodiment of the present invention relay system structural representation;

Fig. 2 is embodiment of the present invention method flow schematic diagram;

Fig. 3 is embodiment of the present invention applicating example schematic diagram;

Fig. 4 is embodiment of the present invention applicating example schematic diagram;

Fig. 5 is embodiment of the present invention applicating example schematic diagram;

Fig. 6 is embodiment of the present invention applicating example schematic diagram;

Fig. 7 is embodiment of the present invention applicating example schematic diagram;

Fig. 8 is embodiment of the present invention Contrast on effect schematic diagram;

Fig. 9 is embodiment of the present invention apparatus structure schematic diagram;

Figure 10 is embodiment of the present invention via node structural representation;

Figure 11 is embodiment of the present invention system configuration schematic diagram;

Figure 12 is embodiment of the present invention system configuration schematic diagram.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiment.Embodiment based in the present invention, those of ordinary skills, not making the every other embodiment obtaining under creative work prerequisite, belong to the scope of protection of the invention.

The embodiment of the present invention proposes the method for power division to reach the object of elevator system performance; Further, the embodiment of the present invention has also proposed the combined optimization method of trunk node selection and power division on the basis of power division, further elevator system performance, above-mentioned combined optimization method application network maximization of utility (Network Utility Maxiume, NUM) method, carries out modeling to system requirements, then by effective protruding optimization solution, obtains optimum power allocation scheme, its performance is better than only carrying out trunk node selection, or only considers power division.

Particularly, after power distribution method is realized, got via node and sent the power from source signal, combined optimization method can be: via node sends from the power of source signal non-vanishing, and the selected participation of via node sends; If the power that via node sends from source signal is zero, relaying joint is not selected, does not participate in sending.Thereby in power division, reach the object that node is selected between to via node.Not only realize power division, also realized the selection of via node.

Above-mentioned power distribution method application NUM method, carries out modeling to system requirements; By set up model conversation, it is protruding Optimized model; Use protruding optimization method to obtain via node and send the power from source signal;

Above-mentioned modeling is the part in NUM method, with maximization of utility, carries out modeling.System requirements refer to indices and the requirement of system self, and system requirements can be constraints and target function.Constraints comprises system power restriction, error rate restriction etc.; Target function is that the parameter that needs is optimized to configuration according to system performance is formulated as utility function in specific system.The parameter of required optimization of can take is variable, using power system capacity as effectiveness, power system capacity is carried out to maximum and turn to target, the variable here and target can be by user according to oneself requirement or consider from the angle of system, the target of system optimization comprises: the maximum capacity that reach system, meet part specific user's demand, or in system transmitting procedure, time delay minimizes, meet each user's requirement capability identical etc.

Protruding optimization method is a kind of than the coverage of linear optimization optimization instrument more widely.Adopt protruding optimization method to solve and there are a lot of advantages.First, the scope that protruding optimization problem covers is very extensive, can complicated optimization problem be solved; Secondly, the relevant solution that solves protruding optimization problem is comparative maturity, and protruding optimization problem can be by being used interior some algorithm and other algorithms that is applicable to protruding optimization to obtain reliably and effectively solving.Protruding optimization has obtained application in a lot of fields, as protruding optimization being applied to solve multiple-input and multiple-output (Multiple Input Multiple Output, MIMO) system antenna, selects problem, the problems such as precoding.

The sending method of signal in a kind of relay system of the embodiment of the present invention, as shown in Figure 2, can consult Fig. 1 simultaneously, comprising:

201: according to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, determine the transmitted power of each via node when the total signal to noise ratio of this relay system maximizes;

The transmitted power of source refers to the gross power of source transmitted signal, for example: source is used broadcast mode transmitted signal, the broadcasting power that transmitted power of above-mentioned source is source; Source is used other mode transmitted signals, the transmitted power of above-mentioned source can for source mail to via node all signals power and; To this embodiment of the present invention, will not limit.

Total transmitted power of all via nodes in above-mentioned relay system between source and destination refer to all via node transmitted signals between source and destination in relay system use power and.

According to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, the transmitted power of determining each via node when the total signal to noise ratio of described relay system maximizes comprises: the second-order condition that maximizes satisfied convex function according to the total signal to noise ratio of relay system, total transmitted power of via node is less than or equal to transmitted power poor of relay system gross power and source, the transmitted power of via node is more than or equal to zero and be less than or equal to the satisfied linear conditions of maximum transmit power of this via node, adopt the method for protruding optimization to determine the transmitted power of each via node when the total signal to noise ratio of relay system maximizes.

Can solve $\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\min \left\{\max \right\{0,\sqrt{\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{v^{*}{b}_i}}-\frac{E_s{a}_i+1}{b_i}\},E_{i\max }\}=E-E_s$ In variable v ^*obtain the power of via node transmission source end signal; E wherein _sthe transmitted power that represents source, E represents total transmitted power of relay system;

it is the transmitted power sum of all via nodes; H wherein _s,irepresent that source is to the channel gain of i via node,

h _i,drepresent that i via node is to the channel gain of destination,

e _imaxthe upper bound that represents i via node transmitted power; N ₀for noise power; Source is s, and destination is d, the m of a relay system via node 1,2 ... m.

202: to all via nodes, send the transmitted power of via node separately; Or, to part via node in above-mentioned all via nodes, sending in above-mentioned part via node the transmitted power of via node separately, the transmitted power of above-mentioned part via node is greater than zero.

Above-mentioned 201～202 executive agent is that via node can be also a kind of third party device except via node and source in relay system.If executive agent is this third party device, by this third party device, determined so the transmitted power of above-mentioned each via node; Said method also comprises: this third party device sends the transmitted power of all via nodes to source, the via node transmitted signal that above-mentioned source is greater than zero to transmitted power in above-mentioned all via nodes.

In the present embodiment, via node is according to the transmitted power transmitted signal receiving.

Realization based on said method embodiment, the embodiment of the present invention gives take the method that via node is executive agent and realizes, and comprising: via node obtains the transmitted power of source; The transmitted power of above-mentioned via node when via node determines that according to the transmitted power of total transmitted power of all via nodes between source in relay system and destination and source the total signal to noise ratio of relay system maximizes; According to the transmitted power of above-mentioned via node, to destination, send signal.

Further, according to the transmitted power of above-mentioned via node, to destination, send signal and comprise: if the transmitted power of above-mentioned via node is greater than zero, according to the transmitted power of above-mentioned via node to destination transmitted signal.

Above-described embodiment, the signal while maximizing by obtaining the total signal to noise ratio of relay system, in the power division of via node, is realized distributing rationally of via node power, promotes relay system performance.Further, making to distribute power in power division is the transmission that zero via node does not participate in data, when realizing power configuration, realize the selection of via node, realized the combined optimization of trunk node selection and power division, further improved systematic function.

For illustrate above-mentioned 201 in the realizability of the formula that provides, refer to Fig. 1, the system of the method application that the embodiment of the present invention provides can comprise a source s, a destination d, and the m of a relay system via node 1,2 ... m.Source communicates with destination under the assistance of via node, and at this, in the present embodiment, transmission channel adopts time-division quadrature, and a setting time slot in each node distribution (m+1) individual time slot is unit length thus; Meanwhile, suppose for multi-subscriber dispatching and can obtain CSI completely at base station end.

If all channels are average is 0, variance is N ₀rayleigh fading Gaussian white noise channel.H wherein _i, _j□ ²representation node i is to the power gain of node j, and s represents source node, and d represents destination node, and 1,2 ..., m represents via node, wherein i and j belong to 1～m.At first time slot, source is to destination and m via node transmitted signal.The signal that a destination and m via node receives is respectively:

$y_{s,d}=\sqrt{E_s}{h}_{s,d}s+n_{s,d}$

$y_{s,i}=\sqrt{E_s}{h}_{s,i}s+n_{s,i}---\left(1\right)$

Wherein, y _s,drepresent the received information directly being sent by source of destination; y _s,irepresent the received information being sent by source of via node i; E _sthe power that represents source signal transmitted; S represents the signal that source sends; h _s,irepresent that source is to the channel gain of i via node, h _s,drepresent that source is to the channel gain of destination; n _s,drepresent that source is to the additive white Gaussian noise of destination, n _s,irepresent that source is to the additive white Gaussian noise of i via node.

For AF agreement, when m via node receives after the signal that source sends, be normalized to the received signal, then send a new signal

to destination, normalization coefficient@meets after the received signal normalization of m via node:

${\tilde{y}}_{s,i}=\frac{\sqrt{E_s}{h}_{s,i}}{\sqrt{E\left\{{\left|y_{s,i}\right|}^2\right\}}}s+\frac{n_{s,i}}{\sqrt{E\left\{{\left|y_{s,i}\right|}^2\right\}}}$

$=\frac{\sqrt{E_s}{h}_{s,i}}{\sqrt{E_s{\left|h_{s,i}\right|}^2+N_0}}s+\frac{n_{s,i}}{\sqrt{E_s{\left|h_{s,i}\right|}^2+N_0}}$ （2）

In an ensuing m time slot, m via node is transferred to destination with power Ei again by the signal after normalization successively, and the received signal being sent by m via node of destination is:

$y_{i,d}=\sqrt{E_i}{h}_{i,d}{\tilde{y}}_{s,i}+n_{i,d}$

$=\sqrt{E_i}{h}_{i,d}(\frac{\sqrt{E_s}{h}_{s,i}}{\sqrt{E_s{\left|h_{s,i}\right|}^2+N_0}}s+\frac{n_{s,i}}{\sqrt{E_s{\left|h_{s,i}\right|}^2+N_0}})+n_{i,d}$

$=\sqrt{\frac{E_s{E}_i}{E_s{\left|h_{s,i}\right|}^2+N_0}}{h}_{i,d}{h}_{s,i}s+\sqrt{\frac{E_i}{E_s{\left|h_{s,i}\right|}^2+N_0}}{h}_{i,d}{n}_{s,i}+n_{i,d}---\left(3\right)$

Wherein, y _i,drepresent the information being sent by i via node that destination is received;

the transmitted power that represents i via node; h _i,drepresent that i via node is to the channel gain of destination; n _i,drepresent that i via node is to the additive white Gaussian noise of destination.

The received signal being sent by m via node of destination is normalized

${\tilde{y}}_{i,d}=\frac{y_{i,d}}{\sqrt{\frac{E_i{\left|h_{i,d}\right|}^2}{E_s{\left|h_{s,i}\right|}^2+{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000173345900022.png,HSA00000173345900031.png"\; state="\{\{state\}\}">N</figure-callout>}}_0}+1}}$

At destination node end, to comprising by source, directly send to signal, and the m road signal after normalization is at Nei m+1 road signal, adopts high specific to merge, total SNR is as follows:

$\mathrm{SNR}=\frac{E_s{\left|h_{s,d}\right|}^2}{{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000173345900022.png,HSA00000173345900031.png"\; state="\{\{state\}\}">N</figure-callout>}}_0}+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{E_s{E}_i\frac{{\left|h_{s,i}\right|}^2}{{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000173345900022.png,HSA00000173345900031.png"\; state="\{\{state\}\}">N</figure-callout>}}_0}\&CenterDot;\frac{{\left|h_{i,d}\right|}^2}{N_0}}{E_s\frac{{\left|h_{s,i}\right|}^2}{{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000173345900022.png,HSA00000173345900031.png"\; state="\{\{state\}\}">N</figure-callout>}}_0}+E_i\frac{{\left|h_{i,d}\right|}^2}{{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000173345900022.png,HSA00000173345900031.png"\; state="\{\{state\}\}">N</figure-callout>}}_0}+1}---\left(4\right)$

Order $a_0=\frac{{\left|h_{s,d}\right|}^2}{{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000173345900022.png,HSA00000173345900031.png"\; state="\{\{state\}\}">N</figure-callout>}}_0},$ $a_i=\frac{{\left|h_{s,i}\right|}^2}{{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000173345900022.png,HSA00000173345900031.png"\; state="\{\{state\}\}">N</figure-callout>}}_0},$ $b_i=\frac{{\left|h_{i,d}\right|}^2}{{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000173345900022.png,HSA00000173345900031.png"\; state="\{\{state\}\}">N</figure-callout>}}_0},$ Can obtain:

$\mathrm{SNR}=E_s{a}_0+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{E_s{E}_i{a}_i{b}_i}{E_s{a}_i+E_i{b}_i+1}---\left(5\right)$

In order to make the outage probability of relay system minimum, should make the total signal to noise ratio of system (Signal-to-Noise Ratio, SNR) maximum.The maximization of utility of system can be maximized as the total SNR of system.Carry out NUM modeling, in system, the restriction for gross power meets

situation under, take and maximize total SNR as target, between source and via node, carry out power division, concrete form is as follows:

$\max \mathrm{imize}{E}_s{a}_0+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{E_s{E}_i{a}_i{b}_i}{E_s{a}_i+E_i{b}_i+1}$

$\mathrm{subjectto}{E}_s+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{E}_i\&le;E$

0≤E _s≤E _smax

0≤E _i≤E _imax （6）

Above this optimization problem be divided into two parts: first is target function, i.e. total SNR, target is that total SNR is maximized; Second portion is constraints; Wherein constraints comprises three: first condition is system total power constraint, and second condition is the Power Limitation of source, and the 3rd condition is the Power Limitation of each via node.Optimization variable in optimization problem (6) is respectively E _s, E _i, i=1 wherein ..., m.From (6), variable E in target function _swith variable E _i, for i=1 ..., there is coupled relation in m.Below provide a kind of method that solves this problem, due to:

$\mathrm{SNR}=E_s{a}_0+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{E_s{E}_i{a}_i{b}_i}{E_s{a}_i+E_i{b}_i+1}=E_s\underset{i=0}{\overset{m}{\mathrm{\&Sigma;}}}{a}_i-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{E_s{a}_i+E_i{b}_i+1}$

Optimization problem (6) can represent that (maximize-maximizes like this; Subject to-constraints):

$\max \mathrm{imize}{E}_s\underset{i=0}{\overset{m}{\mathrm{\&Sigma;}}}{a}_i-\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{E_s{a}_i+E_i{b}_i+1}$

$\mathrm{subjectto}{E}_s+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{E}_i\&le;E$

0≤E _s≤E _smax

0≤E _i≤E _imax

Wherein

e represents total transmitted power of relay system,

a part that represents signal to noise ratio,

a part for signal to noise ratio,

it is the transmitted power sum of all via nodes; E _smaxthe upper bound that represents source transmitted power; E _imaxthe upper bound that represents i via node transmitted power.

If fixing E _s, the first of target function will become a constant so, and problem equivalent is above in (inimize-minimizes; Subject to-constraints):

$\min \mathrm{imize}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{E_s{a}_i+E_i{b}_i+1}$

$\mathrm{subjectto}\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{E}_i\&le;E-E_s$

0≤E _i≤E _imax （7）

Problem after conversion (7) is equivalent to the power transmitted signal of source to fix, and then between via node, carries out optimum power division.Optimal value must meet

variable in this optimization problem is exactly E like this _i, for i=1 ..., m.Because custom represents variable with x, make x=[E below _i..., E _m] ^t,, i.e. x _i=E _ifor i=1, ..., m, by protruding optimum theory, can verify that target function meets the second-order condition of convex function, and the restrictive condition of the equation in (7) and inequality be affine, so this problem is protruding optimization problem, constraints is linear conditions simultaneously, and the protruding optimization problem that is canonical form by this problem representation is:

$\min \mathrm{imize}{f}_0\left(x\right)=\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+{E_{s}a}_i}{E_s{a}_i+x_i{b}_i+1}$

subject to g(x)=1 ^Tx-(E-E _s)=0

h _i(x)=-x _i≤0 for i=1,2,...,m

p _i(x)=x _i-E _imax≤0 for i=1,2,...,m （8）

The process of the optimal solution of Solve problems (8) is carried out the process of power division in fact exactly between each via node.In addition, because the restriction of constraints makes x _imay meet x _i=0, if be 0 for its transmitting power of any one via node, it can not participate in sending, and thus, in power division, has reached the object of carrying out trunk node selection.

This protruding optimization problem can be tried to achieve analytic solutions by Lagrange duality method, introduces the solution procedure of analytic solutions below.

The corresponding Lagrangian of problem (8) is as follows:

$L(x,\mathrm{\&lambda;},\mathrm{\&mu;},v)=f_0\left(x\right)+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&lambda;}}_i{h}_i\left(x\right)+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&mu;}}_i{p}_i\left(x\right)+\mathrm{vg}\left(x\right)$

Due to the target function of optimization problem (8) and restrictive condition are can be micro-, and restrictive condition meets Si Laite (Slater) condition, can use Kuhn-Tucker condition (Karush-Kuhn-Tucker condition, KKT) condition to obtain optimal solution.The KKT condition of this problem is as follows:

$h_i\left(x^{*}\right)=-x_i^{*}\&le;0,$ i=1,...,m

${\mathrm{\&lambda;}}_i^{*}\&GreaterEqual;0,$ i=1,...,m

$p_i\left(x^{*}\right)=x_i^{*}-E_{i\max }\&le;0,$ i=1,...,m

${\mathrm{\&mu;}}_i^{*}\&GreaterEqual;0,$ i=1,...,m

g(x ^*)=1 ^Tx ^*-(E-E _s)=0 (a)

${\mathrm{\&lambda;}}_i^{*}{h}_i\left(x^{*}\right)=0,$ i=1,...,m (b)

${\mathrm{\&mu;}}_i^{*}{p}_i\left(x^{*}\right)=0,$ i=1,...,m (c)

$\&dtri;f_0\left(x^{*}\right)+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&lambda;}}_i^{*}\&dtri;h_i\left(x^{*}\right)+\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&mu;}}_i^{*}\&dtri;p_i\left(x^{*}\right)+v^{*}\&dtri;g\left(x^{*}\right)=0$

$-\frac{(E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i)b_i}{{(E_s{a}_i+x_i^{*}{b}_i+1)}^2}-{\mathrm{\&lambda;}}_i^{*}+{\mathrm{\&mu;}}_i^{*}+v^{*}=0---\left(d\right)$

By (d), obtained, ${\mathrm{\&mu;}}_i^{*}=\frac{(E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i)b_i}{{(E_s{a}_i+x_i^{*}{b}_i+1)}^2}+{\mathrm{\&lambda;}}_i^{*}-v^{*}\&GreaterEqual;0,$ Substitution (c)

$[\frac{(E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i)b_i}{{(E_s{a}_i+x_i^{*}{b}_i+1)}^2}+{\mathrm{\&lambda;}}_i^{*}-v^{*}]\&CenterDot;(x_i^{*}-E_{i\max })=0---\left(9\right)$

By

for by problem reduction, by constraints

tighten for

like this

for i=1 ..., m, so (9) can be reduced to:

$[\frac{(E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i)b_i}{{(E_s{a}_i+x_i^{*}{b}_i+1)}^2}-v^{*}]\&CenterDot;(x_i^{*}-E_{i\max })=0---\left(10\right)$

$v^{*}\&le;\frac{(E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i)b_i}{{(E_s{a}_i+x_i^{*}{b}_i+1)}^2}---\left(11\right)$

To the problems referred to above (10), (11) segmentation discussion, can obtain:

$x_i^{*}=\left\{\begin{array}{cc}0,& v^{*}\&GreaterEqual;\frac{E_s{a}_i{b}_i}{E_s{a}_i+1}\\ \sqrt{\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{v^{*}{b}_i}}-\frac{E_s{a}_i+1}{b_i},& \frac{(E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i)b_i}{{(E_s{a}_i+E_{i\max }{b}_i+1)}^2}<v^{*}<\frac{E_s{a}_i{b}_i}{E_s{a}_i+1}\\ E_{i\max },& v^{*}\&le;\frac{(E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i)b_i}{{(E_s{a}_i+E_{i\max }{b}_i+1)}^2}\end{array}\right.$

V wherein ^*for via node sends the power from source signal, above form can be expressed as simply:

$x_i^{*}=\min \left\{\max \right\{0,\sqrt{\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{v^{*}{b}_i}}-\frac{E_s{a}_i+1}{b_i}\},E_{i\max }\},$ Gross power by each via node is $\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{E}_i=E-E_s,$ $\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{x}_i=E-E_s,$ Resulting optimal solution v ^*meet:

$\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\min \left\{\max \right\{0,\sqrt{\frac{E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i}{v^{*}{b}_i}}-\frac{E_s{a}_i+1}{b_i}\},E_{i\max }\}=E-E_s---\left(12\right)$

Wherein the left side of (12) is about v ^*segmentation monotonic function, there are two flex points $v^{*}=\frac{(E_s^2{a}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HSA00000173345900011.png,HSA00000173345900022.png"\; state="\{\{state\}\}">i</figure-callout>}}^2+E_s{a}_i)b_i}{{(E_s{a}_i+E_{i\max }{b}_i+1)}^2}$ With $v^{*}=\frac{E_s{a}_i{b}_i}{E_s{a}_i+1}$ So can obtain the unique solution of (12).The solution of problem (12) also can adopt the method for similar water flood to try to achieve, and in the process of water filling, each container has top and bottom separately, to this embodiment of the present invention, will not limit.

The test result that the method providing according to above-described embodiment is carried out actual test is illustrated with following scene:

Scene 1: system comprises a source s, a destination d, and 10 via nodes 1,2 ... m.Source communicates with destination under the assistance of via node, and at this, transmission channel is by time-division quadrature for simplicity.Each node distributes in 11 time slots, and setting time slot is unit length.Meanwhile, suppose for multi-subscriber dispatching and can obtain CSI at base station end.Suppose that all channels are that average is 0, the Gaussian white noise channel of the Rayleigh fading that variance is 1.

When Es/E=0.5, solve optimization problem (7), can obtain optimum power division, and optimum trunk node selection.In different SNR situations, selected via node number distributes as shown in Figure 3.Wherein transverse axis is: signal to noise ratio; The longitudinal axis is in different SNR situations, to distribute the non-vanishing via node number of power.

Scene 2: system comprises a source s, a destination d, and 10 via nodes 1,2 ... m.Source communicates with destination under the assistance of via node, and at this, transmission channel is by time-division quadrature for simplicity.Each node distributes in 11 time slots, and setting time slot is unit length.Meanwhile, suppose for multi-subscriber dispatching and can obtain CSI at base station end.Suppose that all channels are that average is 0, the Gaussian white noise channel of the Rayleigh fading that variance is 1.

When Es/E=0.3, adopt this programme, solve optimization problem (7), can obtain optimum power division, and optimum trunk node selection.In different SNR situations, selected via node number distributes as shown in Figure 4, and wherein transverse axis is: signal to noise ratio; The longitudinal axis is in different SNR situations, to distribute the non-vanishing via node number of power.

Scene 3 systems comprise a source s, a destination d, and 10 via nodes 1,2 ... m.Source communicates with destination under the assistance of via node, and at this, transmission channel is by time-division quadrature for simplicity.Each node distributes in 11 time slots, and setting time slot is unit length.Meanwhile, suppose for multi-subscriber dispatching and can obtain CSI at base station end.Suppose that all channels are that average is 0, the Gaussian white noise channel of the Rayleigh fading that variance is 1.

When Es/E=0.1, solve optimization problem (7), can obtain optimum power division, and optimum trunk node selection.In different SNR situations, selected via node number distributes as shown in Figure 5, and wherein transverse axis is: signal to noise ratio; The longitudinal axis is in different SNR situations, to distribute the non-vanishing via node number of power.

Scene 4: system comprises a source s, a destination d, and 10 via nodes 1,2 ... m.Source communicates with destination under the assistance of via node, and at this, transmission channel is by time-division quadrature for simplicity.So, each node distributes in 11 time slots, and setting time slot is unit length.Meanwhile, suppose for multi-subscriber dispatching and can obtain CSI at base station end.Suppose that all channels are that average is 0, the Gaussian white noise channel of the Rayleigh fading that variance is 1.

When SNR is fixed on 15dB, when Es/E gets different value, solve optimization problem (7), can obtain optimum power division, and optimum trunk node selection.Adopt resulting optimal power allocation, and optimum trunk node selection is when transmit, as shown in Figure 6, wherein transverse axis is the bit error rate of system (Bit Error Rate, BER) performance: signal to noise ratio; The longitudinal axis is system bit error rate in different SNR situations.

Scene 5: system comprises a source s, a destination d, and 10 via nodes 1,2 ... m.Source communicates with destination under the assistance of via node, and at this, transmission channel is by time-division quadrature for simplicity.So, each node distributes in 11 time slots, and setting time slot is unit length.Meanwhile, suppose for multi-subscriber dispatching and can obtain CSI at base station end.Suppose that all channels are that average is 0, the Gaussian white noise channel of the Rayleigh fading that variance is 1.

When SNR and Es/E get different value, solve optimization problem (7), can obtain optimum power division, and optimum trunk node selection.Adopt resulting optimal power allocation, and optimum trunk node selection is when transmit, as shown in Figure 8, wherein, vertical direction is BER to the bit error rate of system (BER) performance, and horizontal direction transverse axis is that the SNR longitudinal axis is Es/E.

Above-described embodiment is by adopting NUM method, apply protruding optimum theory, system requirements are carried out to modeling, realized the combined optimization of trunk node selection and power division, can obtain the optimal result of power division and trunk node selection, not only obtained space diversity gain, also power has been carried out to optimization configuration, systematic function is got a promotion.As shown in Figure 8, wherein transverse axis is: signal to noise ratio; The longitudinal axis is system bit error rate in different SNR situations, and the present embodiment scheme is compared with many via nodes of double bounce constant power allocation strategy, and performance obtains the lifting of 3dB.The present invention, by concentrating modeling to obtain combined optimization to system, goes for the system that via node number is larger.

The embodiment of the present invention also provides the dispensing device of signal in a kind of relay system, as shown in Figure 9, comprising:

Power determining unit 901, for according to total transmitted power of all via nodes between relay system source and destination and the transmitted power of above-mentioned source, determines the transmitted power of each via node when the total signal to noise ratio of above-mentioned relay system maximizes;

Power transmitting element 902, for sending the transmitted power of via node separately to all via nodes; Or, to part via node in above-mentioned all via nodes, sending in above-mentioned part via node the transmitted power of via node separately, the transmitted power of above-mentioned part via node is greater than zero.

Further, if said apparatus can be the third party device except above-mentioned via node and source.

Above-mentioned power transmitting element 902, can also be for send the transmitted power of all via nodes to source, the via node transmitted signal that above-mentioned source is greater than zero to transmitted power in above-mentioned all via nodes.

The embodiment of the present invention also provides a kind of trunking, as shown in figure 10, comprising:

Power acquiring unit 1001, for obtaining the transmitted power of source;

Transmitted power determining unit 1002, the transmitted power of above-mentioned via node when determining that according to the transmitted power of total transmitted power of all via nodes between relay system source and destination and source the total signal to noise ratio of relay system maximizes;

Signal transmitting unit 1003, sends signal for the transmitted power according to above-mentioned via node to destination.

Further, above-mentioned signal transmitting unit 1003, if can also be greater than for the transmitted power of above-mentioned via node zero, according to the transmitted power of above-mentioned via node to destination transmitted signal.

The embodiment of the present invention also provides the transmitting system of signal in a kind of relay system, as shown in figure 11, comprise: source 1101, destination 1102 and via node 1103, the trunking that wherein above-mentioned via node 1103 provides for the embodiment of the present invention, or, the dispensing device of signal in the relay system that above-mentioned source 1101 provides for the embodiment of the present invention, or, transmitting system also comprises as shown in figure 12: third party device 1201, the dispensing device of signal or the third party device that the embodiment of the present invention provides in the relay system that above-mentioned third party device provides for the embodiment of the present invention.

Above-described embodiment, the signal while maximizing by obtaining the total signal to noise ratio of relay system, in the power division of via node, is realized distributing rationally of via node power, promotes relay system performance.Further, making to distribute power in power division is the transmission that zero via node does not participate in data, when realizing power configuration, realize the selection of via node, realized the combined optimization of trunk node selection and power division, further improved systematic function.

One of ordinary skill in the art will appreciate that all or part of step realizing in above-described embodiment method is to come the hardware that instruction is relevant to complete by program, above-mentioned program can be stored in a kind of computer-readable recording medium, the above-mentioned storage medium of mentioning can be read-only memory, disk or CD etc.

In a kind of the relay system above embodiment of the present invention being provided, sending method, device and the system of signal are described in detail, applied specific case herein principle of the present invention and execution mode set forth, the explanation of above embodiment just for help to understand method of the present invention and; , for one of ordinary skill in the art, according to scheme provided by the invention, all will change in specific embodiments and applications, to sum up, this description should not be construed as limitation of the present invention meanwhile.

Claims (9)

1. a sending method for signal in relay system, is characterized in that, comprising:

According to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, determine the transmitted power of each via node when the total signal to noise ratio of described relay system maximizes;

To all via nodes, send the transmitted power of via node separately; Or, to part via node in described all via nodes, sending in described part via node the transmitted power of via node separately, the transmitted power of described part via node is greater than zero;

Wherein, described according to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, determine that the transmitted power of each via node when the total signal to noise ratio of described relay system maximizes comprises:

The transmitted power poor, via node that the total transmitted power that maximizes all via nodes between source and destination in the second-order condition, relay system of satisfied convex function according to the total signal to noise ratio of relay system is less than or equal to the transmitted power of relay system gross power and source is more than or equal to zero and be less than or equal to the satisfied linear conditions of maximum transmit power of this via node, the method that adopts protruding optimization, solves

in variable v ^*obtain the power of via node transmission source end signal, determine the transmitted power of each via node when the total signal to noise ratio of relay system maximizes;

Wherein, E _sthe transmitted power that represents source, E represents total transmitted power of relay system;

it is the transmitted power sum of all via nodes; H wherein _s,irepresent that source is to the channel gain of i via node,

h _i,drepresent that i via node is to the channel gain of destination,

e _imaxthe upper bound that represents i via node transmitted power; N ₀for noise power.

2. method according to claim 1, is characterized in that, the transmitted power of described each via node is determined by the third party device outside described via node and described source; Described method also comprises:

Described third party device sends the transmitted power of all via nodes to source, the via node transmitted signal that described source is greater than zero to transmitted power in described all via nodes.

3. a sending method for signal in relay system, is characterized in that, comprising:

Via node obtains the transmitted power of source;

Described via node is according to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, determine when the total signal to noise ratio of relay system maximizes described in the transmitted power of via node;

Described via node according to the transmitted power of described via node to destination transmitted signal;

Wherein, described via node is according to total transmitted power of all via nodes between source in relay system and destination and the transmitted power of described source, determine when the total signal to noise ratio of relay system maximizes described in the transmitted power of via node comprise:

The transmitted power poor, via node that the total transmitted power that maximizes all via nodes between source and destination in the second-order condition, relay system of satisfied convex function according to the total signal to noise ratio of relay system is less than or equal to the transmitted power of relay system gross power and source is more than or equal to zero and be less than or equal to the satisfied linear conditions of maximum transmit power of this via node, the method that adopts protruding optimization, solves

in variable v ^*obtain the power of via node transmission source end signal, determine the transmitted power of each via node when the total signal to noise ratio of relay system maximizes;

Wherein, E _sthe transmitted power that represents source, E represents total transmitted power of relay system; it is the transmitted power sum of all via nodes; H wherein _s,irepresent that source is to the channel gain of i via node, h _i,drepresent that i via node is to the channel gain of destination,

e _imaxthe upper bound that represents i via node transmitted power; N0 is noise power.

4. method according to claim 3, is characterized in that, describedly according to the transmitted power of described via node, to destination transmitted signal, comprises:

If the transmitted power of described via node is greater than zero, according to the transmitted power of described via node to destination transmitted signal.

5. a dispensing device for signal in relay system, is characterized in that, comprising:

Power determining unit, for according to total transmitted power of all via nodes between relay system source and destination and the transmitted power of described source, determines the transmitted power of each via node when the total signal to noise ratio of described relay system maximizes;

Power transmitting element, for sending the transmitted power of via node separately to all via nodes; Or, to part via node in described all via nodes, sending in described part via node the transmitted power of via node separately, the transmitted power of described part via node is greater than zero;

Wherein, described power determining unit specifically for, the transmitted power poor, via node that the total transmitted power that maximizes all via nodes between source and destination in the second-order condition, relay system of satisfied convex function according to the total signal to noise ratio of relay system is less than or equal to the transmitted power of relay system gross power and source is more than or equal to zero and be less than or equal to the satisfied linear conditions of maximum transmit power of this via node, the method that adopts protruding optimization, solves

in variable v ^*obtain the power of via node transmission source end signal, determine the transmitted power of each via node when the total signal to noise ratio of relay system maximizes;

Wherein, E _sthe transmitted power that represents source, E represents total transmitted power of relay system;

it is the transmitted power sum of all via nodes; H wherein _s,irepresent that source is to the channel gain of i via node,

h _i,drepresent that i via node is to the channel gain of destination,

e _imaxthe upper bound that represents i via node transmitted power; N0 is noise power.

6. install according to claim 5, it is characterized in that, described device is the third party device except described via node and source,

Described power transmitting element, also for send the transmitted power of all via nodes to source, the via node transmitted signal that described source is greater than zero to transmitted power in described all via nodes.

7. a trunking, is characterized in that, comprising:

Power acquiring unit, for obtaining the transmitted power of source;

Transmitted power determining unit, when determining that according to the transmitted power of total transmitted power of all via nodes between relay system source and destination and source the total signal to noise ratio of relay system maximizes described in the transmitted power of via node;

Signal transmitting unit, sends signal for the transmitted power according to described via node to destination;

Wherein, described transmitted power determining unit specifically for, the transmitted power poor, via node that the total transmitted power that maximizes all via nodes between source and destination in the second-order condition, relay system of satisfied convex function according to the total signal to noise ratio of relay system is less than or equal to the transmitted power of relay system gross power and source is more than or equal to zero and be less than or equal to the satisfied linear conditions of maximum transmit power of this via node, the method that adopts protruding optimization, solves in variable v ^*obtain the power of via node transmission source end signal, determine the transmitted power of each via node when the total signal to noise ratio of relay system maximizes;

Wherein, E _sthe transmitted power that represents source, E represents total transmitted power of relay system;

it is the transmitted power sum of all via nodes; H wherein _s,irepresent that source is to the channel gain of i via node,

h _i,drepresent that i via node is to the channel gain of destination, e _imaxthe upper bound that represents i via node transmitted power; N0 is noise power.

8. trunking according to claim 7, is characterized in that,

Described signal transmitting unit, if be also greater than zero for the transmitted power of described via node, according to the transmitted power of described via node to destination transmitted signal.

9. the transmitting system of signal in a relay system, comprise: source, destination and via node, it is characterized in that, described via node is the trunking of claim 7, or described source is the device in claim 5, or, also comprise: third party device, described third party device is the device of claim 5 or 6.

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