CN106656405A - Method for minimizing system confidentiality interruption probability using energy station - Google Patents

Abstract

The invention relates to a method for minimizing system confidentiality interruption probability using energy station, comprising: 1) transmitting by an energy station wireless energy to a source node prior to a Theta T time wherein theta represents a time allocation factor ranging from zero (not included) and one (not included) and T represents a time slot; 2) estimating the channel state information of a communication system by the energy station through the listening of the pilot frequencies at the source node, a legal receiving node and an eavesdropping receiving node; through the utilization of the estimated and obtained channel state information, designing a corresponding best beam former w2 by the energy station; 4) in the coming (1-theta)T time, transmitting by the source node the wireless signals to the legal receiving node and eavesdropping by the eavesdropping receiving node the wireless signals; and using the beam former w2 by the energy station to transmit wireless interfering signals to the legal receiving node and the eavesdropping receiving node so as to minimize the system confidentiality interruption probability. According to the invention, an energy station is used to make the physical layers more secure, therefore, raising the confidentiality security performance of the entire communication system substantially.

Description

A kind of method that utilization energy station minimizes system secrecy outage probability

Technical field

The present invention relates to the communications field, and in particular to a kind of utilization energy station minimizes the side of system secrecy outage probability Method.

Background technology

With developing rapidly for wireless communication technology, various Wireless Telecom Equipments are sharply increased, thing followed channel radio Letter safety issue is also on the rise.Traditional secure wireless communication mechanism is mainly the associated encryption skill based on cryptography Art, but with the rapid lifting of Computing ability, the secrecy basis of this technology becomes no longer firm, safety of physical layer skill Art is arisen at the historic moment.

Radio communication safety of physical layer technology is from information-theoretical angle, the uniqueness and reciprocity using physical channel Property realizing that information is encrypted, identification validated user etc., it is intended to realize unconditional security.Chinese invention patent publication number (CN103986545A) a kind of safe transmission method of physical layer for SIMO wireless communication systems is disclosed, expects to receive first Fang Fanxiang launches random reference signal, and then launch party is entered after line shuffle to symbol to be transmitted using the reference signal for receiving and sent out Penetrate, finally expect that recipient is docked the collection of letters number and is demodulated to obtain the information of launch party's transmission using known reference signal.Value Obtain, it is noted that the patent of invention only discloses launch party and perfect can receive expects the reverse random reference signal of recipient Situation, does not account for the scene of limited channel status information feedback.

On the other hand, continuing to bring out with emerging wireless traffic, the cruising time of mobile communication equipment is increasingly becoming shadow Ring the key factor of Consumer's Experience.Under the constantly ripe background of wireless energy transmission technology, researcher is proposed in communication Fixed supply station is disposed in network, energy is provided for the mobile device in network using wireless energy transmission technology.Currently, to the greatest extent Pipe introduces the novel wireless communication network architecture of supply station and has caused international extensive concern, but correlative study work to be still in Starting stage, the application to supply station is limited only to provide energy for mobile device, not yet fully excavates the potential of supply station.

The content of the invention

Present invention aims to the deficiencies in the prior art, there is provided one kind is minimized in system secrecy using energy station The method of disconnected probability, using energy station safety of physical layer performance is lifted.

To solve above-mentioned technical problem, technical scheme provided by the present invention is：

A kind of method that utilization energy station minimizes system secrecy outage probability, described communication system include source node, Legitimate receipt node, eavesdropping receiving node and energy station；Described energy station is configured with N_JRoot antenna, N_J≥1；Described source section Point is configured with N_SRoot antenna, N_S≥1；Described legitimate receipt node and eavesdropping receiving node configuration single antenna, specifically include as Lower step：

1) energy station in front θ T times to source node transmit wireless energy, 0<θ<1 represents time distribution factor, and T is represented One time slot；

2) energy station estimates communication system by intercepting source node, legitimate receipt node and eavesdropping the pilot tone of receiving node In channel condition information；

3) channel condition information that energy station is obtained using estimation, designs corresponding optimum beam figuration device w₂；

4) in rear (1- θ) T time, to legitimate receipt node-node transmission wireless signal, eavesdropping receiving node is to institute for source node The wireless signal stated is eavesdropped, while energy station adopts beamformer w₂Pass to legitimate receipt node and eavesdropping receiving node Defeated wireless interference signal, to minimize the secrecy outage probability of system.

Described secrecy interruption is referred to：When the secrecy capacity of system is less than the given rate of information throughput, secrecy is interrupted.

Described communication system carries out energy transmission respectively according to time distribution factor θ in a time slot T and information is passed It is defeated；In front θ T times, energy station to source node transmits wireless energy；In rear (1- θ) T time, source node is to legitimate receipt Node-node transmission wireless signal, eavesdropping receiving node is eavesdropped to described wireless signal, while energy station is to legitimate receipt section Point and eavesdropping receiving node transmitting wireless interference signal.

Described energy station and source node constitutes wireless energy transfer subsystem；Described source node, legitimate receipt node Transmission of wireless signals subsystem is constituted with eavesdropping receiving node；Described energy station, legitimate receipt node and eavesdropping receiving node Constitute wireless interference signal transmission subsystem.

Described step 2) in channel condition information include：Energy station and source node, source node and legitimate receipt node, source Node is believed with eavesdropping receiving node, energy station and legitimate receipt node and energy station with the channel status of eavesdropping receiving node Breath.

Described step 3) in optimum beam figuration device w₂Its object function is expressed as with constraints：

s.t.||w₂| |=1

Wherein, P_SAnd N₀The maximum transmission power of energy station and the noise power of legitimate receipt node are represented respectively；η is represented Radio frequency signal energy is converted into the energy conversion efficiency of electric energy；H_JS, h_SD, h_SE, h_JDAnd h_JEEnergy station and source are represented respectively Node, source node and legitimate receipt node, source node and eavesdropping receiving node, energy station and legitimate receipt node and energy station With the channel condition information of eavesdropping receiving node；T and ' represent transposition and conjugate operation symbol respectively.

Described optimal launching beam figuration device w₂Its object function is carried out with constraints by the method for semidefinite decoding Conversion, utilizes Conjugate transposition oeprator is represented, while omitting the constraints that W orders are 1, following shape is converted into Formula：

S.t.tr (W)=1

Wherein, tr () is represented and is sought mark oeprator.

Using Charnes-Cooper Transformation Theorems, resulting optimum beam figuration device w₂Established rules by solution following convex half Draw optimization problem to obtain with reference to the method for linear search；

Wherein, linear search is following problem：

Wherein, F (y) is the solution of following convex Semidefinite Programming optimization problem：

S.t.s ＞ 0

Tr (Z)=s

Described convex Semidefinite Programming optimization problem is solved by the CVX kits in MATLAB softwares；Wherein, it is optimum Solution Z is the matrix that order is 1, and is metThat is optimum beam figuration device w₂Obtained by carrying out singular value decomposition to Z Arrive.

Compared with the existing technology, beneficial effects of the present invention are embodied in：

(1) present invention provides a kind of method that utilization energy station minimizes system secrecy outage probability, is carried using energy station Safety of physical layer performance is risen, wireless energy transmission technology is introduced in original tapping channel classical model, by energy station Energy is provided to the device end in system, a kind of wider, the more practical model of range of application is established, it is to avoid traditional mould Type is merely able to be applied to the constraint of low power consumption wireless device terminal, effectively improves the endurance of device end.

(2) in the present invention energy station while energy is provided for terminal, it is also possible to launch as interference source and disturb Signal.The channel condition information obtained using estimation, energy station adjusts and obtains corresponding optimum beam figuration device w₂So that Interference signal is producing less impact to eavesdropping while receiving node produces larger interference on legal receiving node, so as to significantly Lift the secret and safe performance of whole communication system.

Description of the drawings

Fig. 1 is the schematic diagram of the communication system in embodiment；

Fig. 2 is to minimize the method flow diagram of system secrecy outage probability using energy station in embodiment；

Fig. 3 is the relation curve that the secrecy Outage probability of distributed antenna after optimizing in embodiment changes with main channel average signal-to-noise ratio Figure.

Specific embodiment

The present invention is further described with reference to embodiment and Figure of description.

Embodiment

As shown in figure 1, communication system include source node, a legitimate receipt node, an eavesdropping receiving node and One energy station that can launch interference；The energy utilization efficiency of source node is 80%, and time distribution factor is 0.5, energy station Multiple antennas number is 4, and the multiple antennas number of source node is 2.Legitimate receipt node and eavesdropping receiving node configuration single antenna.Its In, energy station and source node constitute wireless energy transfer subsystem；Source node, legitimate receipt node and eavesdropping receiving node are constituted Transmission of wireless signals subsystem；Energy station, legitimate receipt node and eavesdropping receiving node constitute wireless interference signal transmission subsystem System.

As shown in Fig. 2 the method for minimizing system secrecy outage probability using energy station, specifically includes following steps：

1) energy station in front θ T times to source node transmit wireless energy, 0<θ<1 represents time distribution factor, and T is represented One time slot；

2) energy station estimates communication system by intercepting source node, legitimate receipt node and eavesdropping the pilot tone of receiving node In channel condition information；

3) channel condition information that energy station is obtained using estimation, designs corresponding optimum beam figuration device w₂；

4) in rear (1- θ) T time, to legitimate receipt node-node transmission wireless signal, eavesdropping receiving node is to institute for source node The wireless signal stated is eavesdropped, while energy station adopts beamformer w²Pass to legitimate receipt node and eavesdropping receiving node Defeated wireless interference signal, to minimize the secrecy outage probability of system.

Communication system carries out respectively energy transmission and information transfer in a time slot T according to time distribution factor θ；Front In θ T times, energy station to source node transmits wireless energy；In rear (1- θ) T time, source node is to legitimate receipt node-node transmission Wireless signal, eavesdropping receiving node is eavesdropped to described wireless signal, while energy station is to legitimate receipt node and eavesdropping Receiving node launches wireless interference signal, and when the secrecy capacity of system is less than the given rate of information throughput, secrecy is interrupted.

Described step 2) in channel condition information include：Energy station and source node, source node and legitimate receipt node, source Node is believed with eavesdropping receiving node, energy station and legitimate receipt node and energy station with the channel status of eavesdropping receiving node Breath.

Described step 3) in optimum beam figuration device w₂Its object function is expressed as with constraints：

s.t.||w₂| |=1

Wherein, P_SAnd N₀The maximum transmission power of energy station and the noise power of legitimate receipt node are represented respectively；η is represented Radio frequency signal energy is converted into the energy conversion efficiency of electric energy；H_JS, h_SD, h_SE, h_JDAnd h_JEEnergy station and source are represented respectively Node, source node and legitimate receipt node, source node and eavesdropping receiving node, energy station and legitimate receipt node and energy station With the channel condition information of eavesdropping receiving node；T and ' represent transposition and conjugate operation symbol respectively.

Described optimal launching beam figuration device w₂Its object function is carried out with constraints by the method for semidefinite decoding Conversion, utilizes Conjugate transposition oeprator is represented, while omitting the constraints that W orders are 1, is converted into as follows Form：

S.t.tr (W)=1

Wherein, tr () is represented and is sought mark oeprator.

Using Charnes-Cooper Transformation Theorems, resulting optimum beam figuration device w₂Established rules by solution following convex half Draw optimization problem to obtain with reference to the method for linear search；

Wherein, linear search is following problem：

Wherein, F (y) is the solution of following convex Semidefinite Programming optimization problem：

S.t.s ＞ 0

Tr (Z)=s

Described convex Semidefinite Programming optimization problem is solved by the CVX kits in MATLAB softwares；Wherein, it is optimum Solution Z is the matrix that order is 1, and is metThat is optimum beam figuration device w₂Obtained by carrying out singular value decomposition to Z Arrive.

Performance evaluation

The performance change of system in prove embodiment, the present embodiment is carried out point using secrecy Outage probability of distributed antenna parameter Analysis.Fig. 3 is the graph of relation that the secrecy Outage probability of distributed antenna after optimizing in the present embodiment changes with main channel average signal-to-noise ratio.

Here, we adopt other two kinds of basic schemes as reference：With reference to one i.e. transmission antenna selection strategy, using institute The channel condition information of acquisition, selects one to disturb legal receiving node minimum antenna transmission wireless interference signal；Reference Two i.e. high specific sending strategy, utilizes obtained channel condition information, and antenna alignment eavesdropping receiving node transmitting is wireless dry Signal is disturbed, to cause larger interference to it.

By contrast it is found that the best performance under optimum beam figuration device strategy, has thus confirmed the method for designing Validity.Simultaneously from figure 3, it can be seen that with the increase of main channel average signal-to-noise ratio, the secrecy outage probability of system is not Disconnected to reduce, i.e. the performance of system is constantly lifted.

The preferred embodiment of the present invention is the foregoing is only, not to limit the present invention, all spirit in the present invention Within principle, any modification, equivalent substitution and improvements made etc. should be included within the scope of the present invention.

Claims (6)

1. a kind of method that utilization energy station minimizes system secrecy outage probability, described communication system includes source node, closes Method receiving node, eavesdropping receiving node and energy station；Described energy station is configured with N_JRoot antenna, N_J≥1；Described source node It is configured with N_SRoot antenna, N_S≥1；Described legitimate receipt node and eavesdropping receiving node configures single antenna, it is characterised in that Specifically include following steps：

1) energy station in front θ T times to source node transmit wireless energy, 0<θ<1 represents time distribution factor, and T represents one Time slot；

2) energy station by intercept source node, legitimate receipt node and eavesdropping receiving node pilot tone, estimate communication system in Channel condition information；

3) channel condition information that energy station is obtained using estimation, designs corresponding optimum beam figuration device w₂；

4) in rear (1- θ) T time, to legitimate receipt node-node transmission wireless signal, eavesdropping receiving node is to described for source node Wireless signal is eavesdropped, while energy station adopts beamformer w₂To legitimate receipt node and eavesdropping receiving node transmission nothing Line interference signal, to minimize the secrecy outage probability of system.

2. the method that utilization energy station according to claim 1 minimizes system secrecy outage probability, it is characterised in that institute The energy station stated and source node constitute wireless energy transfer subsystem；Described source node, legitimate receipt node and eavesdropping are received Node constitutes transmission of wireless signals subsystem；Described energy station, legitimate receipt node and eavesdropping receiving node constitute wireless dry Disturb signal transmission subsystem.

3. the method that utilization energy station according to claim 1 minimizes system secrecy outage probability, it is characterised in that institute The step of stating 2) in channel condition information include：Energy station and source node, source node and legitimate receipt node, source node and eavesdropping Receiving node, energy station and legitimate receipt node and energy station and the channel condition information for eavesdropping receiving node.

4. the method that utilization energy station according to claim 1 minimizes system secrecy outage probability, it is characterised in that institute The step of stating 3) in optimum beam figuration device w₂Its object function is expressed as with constraints：

$\begin{array}{cc}\underset{w_2}{max}& \frac{1+\frac{\frac{\mathrm{\&eta;}}{N_J}\frac{\mathrm{\&theta;}}{1-\mathrm{\&theta;}}\left|\right|h_{SD}\left|{|}^2\right|\left|H_{JS}\right|{|}^2}{|h_{JD}^T{w}_2{|}^2+\frac{N_0}{P_S}}}{1+\frac{\frac{\mathrm{\&eta;}}{N_J}\frac{\mathrm{\&theta;}}{1-\mathrm{\&theta;}}\frac{|h_{SE}^T{h}_{SD}^{\&prime;}{|}^2}{\left|\right|h_{SD}|{|}^2}\left|\right|H_{JS}|{|}^2}{|h_{JE}^T{w}_2{|}^2}}\end{array}$

s.t.||w₂| |=1

Wherein, P_SAnd N₀The maximum transmission power of energy station and the noise power of legitimate receipt node are represented respectively；η represents wireless Radio frequency energy is converted into the energy conversion efficiency of electric energy；H_JS, h_SD, h_SE, h_JDAnd h_JEEnergy station and source node are represented respectively, Source node and legitimate receipt node, source node and eavesdropping receiving node, energy station and legitimate receipt node and energy station with steal Listen the channel condition information of receiving node；T and respectively expression transposition and conjugate operation symbol.

5. the method that utilization energy station according to claim 4 minimizes system secrecy outage probability, it is characterised in that institute The optimal launching beam figuration device w for stating₂Its object function is converted with constraints by the method for semidefinite decoding, is utilized Conjugate transposition oeprator is represented, while omitting the constraints that W orders are 1, following form is converted into：

$\begin{array}{cc}\underset{W}{max}& \frac{1+\frac{\frac{\mathrm{\&eta;}}{N_J}\frac{\mathrm{\&theta;}}{1-\mathrm{\&theta;}}\left|\right|h_{SD}\left|{|}^2\right|\left|H_{JS}\right|{|}^2}{tr\left({\mathrm{Wh}}_{JD}^{\&prime;}{h}_{JD}^T\right)+\frac{N_0}{P_S}}}{1+\frac{\frac{\mathrm{\&eta;}}{N_J}\frac{\mathrm{\&theta;}}{1-\mathrm{\&theta;}}\frac{|h_{SE}^T{h}_{SD}^{\&prime;}{|}^2}{\left|\right|h_{SD}|{|}^2}\left|\right|H_{JS}|{|}^2}{tr\left({\mathrm{Wh}}_{JE}^{\&prime;}{h}_{JE}^T\right)}}\end{array}$

S.t.tr (W)=1

Wherein, tr () is represented and is sought mark oeprator.

6. the method that utilization energy station according to claim 5 minimizes system secrecy outage probability, it is characterised in that profit Use Charnes-Cooper Transformation Theorems, resulting optimum beam figuration device w₂By the following convex Semidefinite Programming optimization problem of solution Obtain with reference to the method for linear search；

Wherein, linear search is following problem：

$\begin{array}{cc}\underset{y}{min}& \frac{1+F\left(y\right)}{1+\frac{\mathrm{\&eta;}}{N_J}\frac{\mathrm{\&theta;}}{1-\mathrm{\&theta;}}\frac{\left|\right|h_{SD}\left|{|}^2\right|\left|H_{JS}\right|{|}^2}{y}}\end{array}$

$\begin{array}{cc}s.t.& y\&Element;\&lsqb;\frac{N_0}{P_S},\frac{N_0}{P_S}+\left|\right|h_{JD}|{|}^2\&rsqb;,\end{array}$

Wherein, F (y) is the solution of following convex Semidefinite Programming optimization problem：

$\begin{array}{cc}\underset{Z,s}{min}& \frac{\mathrm{\&eta;}}{N_J}\frac{\mathrm{\&theta;}}{1-\mathrm{\&theta;}}\frac{|h_{SE}^T{h}_{SD}^{\&prime;}{|}^2}{\left|\right|h_{SD}|{|}^2}\left|\right|H_{JS}|{|}^{2}s\end{array}$

S.t.s ＞ 0

Tr (Z)=s

$tr\left({\mathrm{Zh}}_{JE}^{\&prime;}{h}_{JE}^T\right)=1$

$tr\left({\mathrm{Zh}}_{JD}^{\&prime;}{h}_{JD}^T\right)=s*(y-\frac{N_0}{P_S})$

Described convex Semidefinite Programming optimization problem is solved by the CVX kits in MATLAB softwares；Wherein, optimal solution Z It is matrix that order is 1, and meetsThat is optimum beam figuration device w₂Obtained by carrying out singular value decomposition to Z.