Nothing Special   »   [go: up one dir, main page]

CN113286292B - Combined optimization method and system for hidden rate of reconfigurable intelligent surface auxiliary communication - Google Patents

Combined optimization method and system for hidden rate of reconfigurable intelligent surface auxiliary communication Download PDF

Info

Publication number
CN113286292B
CN113286292B CN202110540961.1A CN202110540961A CN113286292B CN 113286292 B CN113286292 B CN 113286292B CN 202110540961 A CN202110540961 A CN 202110540961A CN 113286292 B CN113286292 B CN 113286292B
Authority
CN
China
Prior art keywords
transmitter
rate
joint optimization
state information
channel state
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110540961.1A
Other languages
Chinese (zh)
Other versions
CN113286292A (en
Inventor
张广驰
邹丽
张景
成俊峰
湛月
崔苗
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangdong University of Technology
Original Assignee
Guangdong University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangdong University of Technology filed Critical Guangdong University of Technology
Priority to CN202110540961.1A priority Critical patent/CN113286292B/en
Publication of CN113286292A publication Critical patent/CN113286292A/en
Application granted granted Critical
Publication of CN113286292B publication Critical patent/CN113286292B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K3/00—Jamming of communication; Counter-measures
    • H04K3/60—Jamming involving special techniques
    • H04K3/68—Jamming involving special techniques using passive jamming, e.g. by shielding or reflection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
    • H04W12/02—Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K3/00—Jamming of communication; Counter-measures
    • H04K3/80—Jamming or countermeasure characterized by its function
    • H04K3/82—Jamming or countermeasure characterized by its function related to preventing surveillance, interception or detection
    • H04K3/827—Jamming or countermeasure characterized by its function related to preventing surveillance, interception or detection using characteristics of target signal or of transmission, e.g. using direct sequence spread spectrum or fast frequency hopping
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/02—Arrangements for optimising operational condition
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/06—Testing, supervising or monitoring using simulated traffic
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computer Security & Cryptography (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Aiming at the technical problem, the invention provides a method and a system for jointly optimizing the hidden rate of the auxiliary communication of the reconfigurable intelligent surface, and under the condition of ensuring that the information sent by a transmitter is not detected, the receiving power of a legal receiver is maximized by jointly optimizing the transmitting power of the transmitter and the reflection phase of the reconfigurable intelligent surface, so that the hidden communication rate is optimized; in the optimization process, the condition of variable coupling is well avoided, and the concealment of the wireless communication system can be better improved.

Description

Hiding rate joint optimization method and system for reconfigurable intelligent surface auxiliary communication
Technical Field
The invention relates to the technical field of wireless communication, in particular to application of a reconfigurable intelligent surface technology in the aspect of covert communication, and more particularly relates to a method and a system for jointly optimizing the covert rate of reconfigurable intelligent surface auxiliary communication.
Background
A reconfigurable intelligent interactive surface (RIS) is a software-controlled meta-surface consisting of a large number of passive scattering elements or reflecting elements. By manipulating the phase of the impinging signal in a full-duplex manner, the RIS is able to shape the randomly fading channel environment into an intelligent environment to achieve an intelligent and reconfigurable wireless environment. Unlike traditional active transport, the RIS does not require a transport radio frequency chain, which reduces energy and hardware costs compared to existing active component-based technologies. Inspired by the potential capabilities of RIS, RIS-assisted wireless communication has received a great deal of research attention.
Unlike conventional encryption techniques that aim to protect confidential information content, covert communication is intended to protect the presence of legitimate transmissions, or to prevent a malicious eavesdropper from detecting the communication. Covert communication has a higher level of security than existing encryption techniques. The wireless covert communication based on the physical layer hides information in noise, and by using the physical layer security method, a legal user can block the detection of a monitor by using the inherent properties of uncertainty of a wireless channel, randomness of noise and the like. Different from the traditional cryptography method, the covert communication not only ensures that the content of the transmitted information is not stolen, but also ensures that the existence of the information in the transmission process is not discovered.
Publication No. 2020.8.13: the method applies the RIS technology to a Covert communication system and applies the RIS to assist in enhancing the Covert rate. The covert rate is the rate at which a legitimate user receives information without eavesdropping. However, in the prior art, only the false detection rate constraint is considered, and the adopted model is too ideal and has a large difference with the actual application, so that the method still has limitations.
Disclosure of Invention
Aiming at the limitation of the prior art, the invention provides a method and a system for jointly optimizing the concealment rate of reconfigurable intelligent surface auxiliary communication, wherein the technical scheme adopted by the invention is as follows:
a joint optimization method for hiding rate of reconfigurable intelligent surface auxiliary communication comprises the following steps:
s1, constructing a covert communication model consisting of a transmitter, a legal receiver, an illegal detector and a reconfigurable intelligent surface;
s2, constructing a joint optimization problem which aims to maximize the concealment rate and takes the transmitting power of the transmitter and the reflection phase of the reconfigurable intelligent surface as variables to be optimized according to the covert communication model;
s3, acquiring channel state information among the transmitter, the legal receiver, the illegal detector and the reconfigurable intelligent surface;
and S4, solving the joint optimization problem according to the channel state information to obtain the optimal combination of the transmitting power and the reflection phase.
Compared with the prior art, the method and the device have the advantages that under the condition that the information sent by the transmitter is not detected, the transmitting power of the transmitter and the reflection phase of the reconfigurable intelligent surface are jointly optimized, so that the receiving power of the legal receiver is maximized, and the covert communication rate is optimized; in the optimization process, the condition of variable coupling is well avoided, and the concealment of the wireless communication system can be better improved.
As a preferred solution, the joint optimization problem is expressed by the following formula:
Figure BDA0003071550200000021
s.t.P a ≤P max ；
Figure BDA0003071550200000022
Figure BDA0003071550200000023
wherein,
Figure BDA0003071550200000024
reflecting phase, P, representing reconfigurable smart surfaces a Denotes the transmission power, h, of the transmitter AB Indicating channel state information between the transmitter and the legitimate receiver, h IB Representing channel state information between reconfigurable smart surface and legitimate receiver, h AI Representing channel state information between the transmitter and the reconfigurable smart surface, P max Denotes the transmit power limit, h, of the transmitter AW The method comprises the steps of representing channel state information between a transmitter and an illegal detector, representing a false detection rate threshold of the illegal detector for communication between the transmitter and a legal receiver, and representing the total number of reflection elements of a reconfigurable intelligent surface.
Further, in the step S4, the following steps are included:
s41, according to the value of the transmitting power, decomposing the joint optimization problem into a first sub-problem and a second sub-problem, wherein only the reflection phase is reserved as a variable to be optimized;
s42, respectively solving the first sub-problem and the second sub-problem to obtain a first optimal concealment rate and a second optimal concealment rate;
and S43, calculating the optimal combination of the transmitting power and the reflection phase according to the first preferred concealment rate and the second preferred concealment rate.
Further, in step S41, the transmit power is limited
Figure BDA0003071550200000031
In case of (1), take P a ＝P max By replacement of variables such that
Figure BDA0003071550200000032
Deriving from the joint optimization problem the following first sub-problem:
Figure BDA00030715502000000315
Figure BDA0003071550200000034
Figure BDA0003071550200000035
wherein:
Figure BDA0003071550200000036
Figure BDA0003071550200000037
Figure BDA0003071550200000038
further, in the step S42, the process of solving the first sub-problem is as follows:
with v is H R B v＝tr(R B vv H ),v H R W v＝tr(R W vv H )，V＝vv H And performing semi-positive definite relaxation on a constraint term in the first sub-problem, so that the first sub-problem is adjusted to be in the following form, and then a first optimal concealment rate is obtained through convex optimization solution and Gaussian random method solution:
Figure BDA00030715502000000314
Figure BDA00030715502000000310
Figure BDA00030715502000000311
Figure BDA00030715502000000312
further, in step S41, the transmit power is limited
Figure BDA00030715502000000313
In case of (1), take
Figure BDA0003071550200000041
By replacement of variables such that
Figure BDA0003071550200000042
Deriving from the joint optimization problem the following second sub-problem:
Figure BDA0003071550200000043
Figure BDA0003071550200000044
Figure BDA0003071550200000045
wherein:
Figure BDA0003071550200000046
Figure BDA0003071550200000047
Figure BDA0003071550200000048
further, in the step S42, the process of solving the second sub-problem is as follows:
with v H R B v＝tr(R B vv H ),v H R W v＝tr(R W vv H )，V＝vv H After semi-positive relaxation of the constraint term in the second subproblem, to
Figure BDA0003071550200000049
X = μ V, such that the second sub-problem is adjusted to the following form and then solved by convex optimization and gaussian random methods to obtain a second preferred concealment rate:
Figure BDA00030715502000000414
s.t.tr(R W X)+μ|h AW | 2 ＝λ；
Figure BDA00030715502000000411
Figure BDA00030715502000000412
P max ≥μ。
further, in step S43, the optimal combination of the transmission power and the reflection phase
Figure BDA00030715502000000413
Obtained according to the following formula:
Figure BDA0003071550200000051
wherein
Figure BDA0003071550200000052
For the purpose of the first preferred rate of concealment,
Figure BDA0003071550200000053
is the second preferred concealment rate.
Preferably, the covert communication model employs a bounded uncertainty model of channel uncertainty and noise uncertainty at the position of the illegal detector;
the optimal value of the false detection rate threshold lambda of the illegal detector for the communication between the transmitter and the legal receiver is
Figure BDA0003071550200000054
Wherein p represents the noise uncertainty at the location of the illegal detector,
Figure BDA0003071550200000055
representing an upper noise bound in the noise uncertainty.
The present invention also provides the following:
a hidden rate joint optimization system for reconfigurable intelligent surface auxiliary communication comprises a hidden communication model building module, a joint optimization problem building module, a channel state information acquisition module and an optimal combination acquisition module; the joint optimization problem construction module is connected with the covert communication model construction module and the optimal combination acquisition module, and the optimal combination acquisition module is connected with the channel state information acquisition module; wherein:
the covert communication model building module is used for building a covert communication model consisting of a transmitter, a legal receiver, an illegal detector and a reconfigurable intelligent surface;
the joint optimization problem construction module is used for constructing a joint optimization problem which takes the transmitting power of the transmitter and the reflection phase of the reconfigurable intelligent surface as variables to be optimized in order to maximize the concealment rate according to the covert communication model;
the channel state information acquisition module is used for acquiring the channel state information among the transmitter, the legal receiver, the illegal detector and the reconfigurable intelligent surface;
and the optimal combination acquisition module is used for solving the joint optimization problem according to the channel state information to obtain the optimal combination of the transmitting power and the reflection phase.
Drawings
Fig. 1 is a schematic flowchart of a hidden rate joint optimization method for reconfigurable intelligent surface assisted communication according to embodiment 1 of the present invention;
FIG. 2 is a schematic diagram of a covert communication model provided in embodiment 1 of the present invention;
fig. 3 is a schematic flowchart of step S4 provided in embodiment 1 of the present invention;
FIG. 4 is the comparison result of the number of RIS reflection elements in the simulation experiment of the embodiment 1 of the present invention;
FIG. 5 is a comparison result of noise uncertainty in the simulation experiment of embodiment 1 of the present invention;
FIG. 6 is a schematic diagram of a hidden rate joint optimization system for reconfigurable intelligent surface-assisted communication according to an embodiment of the present invention;
description of the reference numerals: 1. a covert communication model building module; 2. a joint optimization problem construction module; 3. a channel state information acquisition module; 4. and an optimal combination obtaining module.
Detailed Description
The drawings are for illustrative purposes only and are not to be construed as limiting the patent;
it should be understood that the embodiments described are only some embodiments of the present application, and not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without any creative effort belong to the protection scope of the embodiments in the present application.
The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the present application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.
The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the application, as detailed in the claims that follow. In the description of the present application, it is to be understood that the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not necessarily used to describe a particular order or sequence, nor are they to be construed as indicating or implying relative importance. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
Further, in the description of the present application, "a plurality" means two or more unless otherwise specified. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. The invention is further illustrated below with reference to the figures and examples.
In order to solve the limitation of the prior art, the present embodiment provides a technical solution, and the technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.
Example 1
A joint optimization method for hidden rate of reconfigurable intelligent surface-assisted communication, please refer to fig. 1, comprising the following steps:
s1, constructing a covert communication model consisting of a transmitter, a legal receiver, an illegal detector and a reconfigurable intelligent surface;
s2, constructing a joint optimization problem which aims to maximize the concealment rate and takes the transmitting power of the transmitter and the reflection phase of the reconfigurable intelligent surface as variables to be optimized according to the covert communication model;
s3, acquiring channel state information among the transmitter, the legal receiver, the illegal detector and the reconfigurable intelligent surface;
and S4, solving the joint optimization problem according to the channel state information to obtain the optimal combination of the transmitting power and the reflection phase.
Compared with the prior art, the method and the device have the advantages that under the condition that the information sent by the transmitter is not detected, the transmitting power of the transmitter and the reflection phase of the reconfigurable intelligent surface are jointly optimized, so that the receiving power of the legal receiver is maximized, and the covert communication rate is optimized; in the optimization process, the condition of variable coupling is well avoided, and the concealment of the wireless communication system can be better improved.
Specifically, in an alternative embodiment, referring to fig. 2, the covert communication model includes a transmitter Alice comprising a single antenna; the legal receiver Bob is a single-antenna receiver; illegal detector Willie is a single antenna user that configures the power detector; the reconfigurable intelligent surface RIS is composed of N reflection elements and used for reflecting signals sent by the transmitter and playing a role in assisting relay. The communication scene of the covert communication model is as follows: the method is characterized in that a transmitter Alice transmits information to a legal receiver Bob in a concealed mode, a potential illegal detector Willie finds that communication is carried out between the transmitter Alice and the legal receiver Bob, and the RIS is deployed between the Alice and the Bob and tries to strengthen signals transmitted to the Bob in a relay reflection process and weaken signals transmitted to the Willie in the relay reflection process.
As a preferred embodiment, the covert communication model employs a bounded uncertainty model of channel uncertainty and the presence of noise uncertainty at the position of the illegal detector.
Specifically, in the covert communication model, the detection strategy of the illegal detector Willie is as follows:
first, the received signal of the illegal detector Willie is
Figure BDA0003071550200000081
Wherein H 0 Indicating that the transmitter Alice has not sent information to the legitimate receiver Bob, H 1 Indicating that the transmitter Alice sends information to a legitimate receiver Bob, n w Is additive white gaussian noise where illegal detector Willie is located,
Figure BDA0003071550200000082
wherein,
Figure BDA0003071550200000083
to be provided with
Figure BDA0003071550200000084
Due to the existence of channel uncertainty, channel estimation errors exist in the reflection link generated by the reconfigurable intelligent surface RIS, and thenIs provided with
Figure BDA0003071550200000085
Wherein
Figure BDA0003071550200000086
Denotes an uncertain channel, beta ∈ [0,1 ]]Is the channel uncertainty.
In the covert communication model, a Probability Density Function (PDF) of noise is a function of a probability density of noise (PDF), which may be caused by changes in temperature and environmental noise, corresponding to an actual application environment
Figure BDA0003071550200000087
For illegal detector Willie, if binary detection is used, its acceptance power is
Figure BDA0003071550200000088
Wherein H 0 Indicating that the transmitter Alice has not sent information to the legitimate receiver Bob, H 1 Indicating that the transmitter Alice sends information to the legitimate receiver Bob; for illegal detector Willie for certain channels in the cascade of reflection links from transmitter Alice to illegal detector Willie
Figure BDA0003071550200000089
The detection performance of the illegal detector Willie adopts a false detection rate
Figure BDA00030715502000000810
To measure, P FA Is false alarm (false alarm) probability, P MD Probability of missing detection:
Figure BDA00030715502000000811
Figure BDA00030715502000000812
D 0 meaning that no information transmission is detected by the illegal detector Willie, D 1 Indicating Willie detected presence information transmission and λ represents false detection rate threshold, the false detection rate of illegal detector Willie can be written as follows:
Figure BDA00030715502000000813
generally speaking, the illegal detector Willie needs to set an optimal value for the false detection rate threshold so as to minimize the false detection rate, i.e. the illegal detector Willie needs to set the optimal value
Figure BDA0003071550200000091
The detection performance of the illegal detector Willie is strongest under the optimal value, so that the condition that the transmitter Alice sends information to the legal receiver Bob is not easy to miss detection, and the condition that the transmitter Alice does not send information to the legal receiver Bob is not easy to falsely alarm; in contrast, under the optimal value, the threat faced by covert communication is the largest, and the performance requirement on the communication system is also the highest; therefore, for the embodiment, on one hand, the covert communication adopts a bounded uncertain model with uncertain channels and noise uncertainty at the position of the illegal detector, and is closer to the practical application scene, and meanwhile, the transmission of covert information is well protected due to environment noise and the uncertainty of an eavesdropper on the channels, which is beneficial to enhancing the concealment; on the other hand, an optimal value is set for the false detection rate threshold of the illegal detector Willie in the covert communication model, and joint optimization is performed on the basis, so that the method is closer to the practical application scene, and the finally obtained joint optimization effect is better.
In particular, to
Figure BDA0003071550200000092
Is a broad senseThe non-central chi-square variable of (2) having a non-central parameter of
Figure BDA0003071550200000093
With a degree of freedom of 2, the expression of the probability density function of X is
Figure BDA0003071550200000094
Wherein, I 0 (. DEG) is a zero-order first modified Bessel function, which can be obtained from the formula
Figure BDA0003071550200000095
When in use
Figure BDA0003071550200000096
Then, the second integral in the above formula is 0, and the false detection rate is then determined
Figure BDA0003071550200000097
When in use
Figure BDA0003071550200000098
When the temperature of the water is higher than the set temperature,
Figure BDA0003071550200000099
is an increasing function with respect to λ; therefore, to minimize the false detection rate, the value range of the optimal detection threshold should be within
Figure BDA00030715502000000910
In this range, the false detection rate is
Figure BDA0003071550200000101
Wherein
Figure BDA0003071550200000102
From the above formulaIn the knowledge that,
Figure BDA0003071550200000103
for λ being a monotonically decreasing function, and therefore, in a preferred embodiment, to minimize the false detection rate, the illegal detector optimally takes the value of the false detection rate threshold λ for communications between the transmitter and the legitimate receiver as
Figure BDA0003071550200000104
Wherein p represents the noise uncertainty at the location of the illegal detector,
Figure BDA0003071550200000105
representing an upper noise bound in the noise uncertainty.
Meanwhile, the corresponding minimum false detection rate is
Figure BDA0003071550200000106
The joint optimization method of the embodiment is to realize the receiving rate of the legal receiver Bob by jointly optimizing the transmitting power of the transmitter Alice and the reflection phase of the reconfigurable intelligent surface RIS
Figure BDA0003071550200000107
Due to monotonicity of the logarithmic function in the expression of the reception rate of the legitimate receiver Bob, the optimization goal of the joint optimization can be simplified equivalently to pursuing the reception power of the legitimate receiver Bob
Figure BDA0003071550200000108
Maximization of (2); in other words, in the present embodiment, maximizing the reception power is maximizing the reception rate.
Therefore, as a preferred embodiment, the joint optimization problem is expressed by the following formula:
Figure BDA0003071550200000109
s.t.P a ≤P max ；
Figure BDA00030715502000001010
Figure BDA00030715502000001011
wherein,
Figure BDA00030715502000001012
representing the reflected phase, P, of a reconfigurable smart surface a Is represented by h AB Indicating channel state information between the transmitter and the legitimate receiver, h IB Representing channel state information between reconfigurable smart surfaces and legitimate receivers, h AI Representing channel state information between the transmitter and the reconfigurable smart surface, P max Denotes the transmit power limit, h, of the transmitter AW The method comprises the steps of representing channel state information between a transmitter and an illegal detector, representing a false detection rate threshold of the illegal detector for communication between the transmitter and a legal receiver, and representing the total number of reflection elements of a reconfigurable intelligent surface.
In particular, in the second constraint term of the joint optimization problem, two variables to be optimized, namely the transmission power P of the transmitter a Reflection phase with reconfigurable smart surface
Figure BDA0003071550200000111
Coupling exists between the two, and the third constraint is not a convex set, so the optimization problem is a non-convex problem, and the optimal solution is difficult to directly solve;
therefore, further referring to fig. 3, in the step S4, the following steps are included:
s41, according to the value of the transmitting power, decomposing the joint optimization problem into a first sub-problem and a second sub-problem, wherein only the reflection phase is reserved as a variable to be optimized;
s42, respectively solving the first sub-problem and the second sub-problem to obtain a first optimal concealment rate and a second optimal concealment rate;
s43, calculating the optimal combination of the transmitting power and the reflection phase according to the first optimal concealment rate and the second optimal concealment rate.
Specifically, as can be seen from the expression of the joint optimization problem, the transmission power of one of the variables to be optimized is set to be
Figure BDA0003071550200000112
Therefore, according to the value of the transmitting power, the joint optimization problem can be split into only one variable reflection phase to be optimized
Figure BDA0003071550200000113
The two subproblems are solved respectively to obtain respective optimal solutions of the two subproblems, and then the solution with better performance is taken as the global optimal solution.
Further, in step S41, the transmit power is limited
Figure BDA0003071550200000114
In case of (1), take P a ＝P max The joint optimization problem will be expressed as
Figure BDA0003071550200000115
Figure BDA0003071550200000116
Figure BDA0003071550200000117
By variable replacement
Figure BDA0003071550200000118
Deriving from the joint optimization problem the following first sub-problem:
Figure BDA00030715502000001213
Figure BDA0003071550200000122
Figure BDA0003071550200000123
wherein:
Figure BDA0003071550200000124
Figure BDA0003071550200000125
Figure BDA0003071550200000126
specifically, the first sub-problem is still a problem that is difficult to solve, and therefore, in step S42, the process of solving the first sub-problem is as follows:
with v is H R B v＝tr(R B vv H ),v H R W v＝tr(R W vv H )，V＝vv H And performing semi-positive definite relaxation on a constraint term in the first subproblem, so that the first subproblem is adjusted to be in the following form, and then a first optimal concealment rate is obtained by convex optimization solution and Gaussian random method solution:
Figure BDA00030715502000001214
Figure BDA0003071550200000128
Figure BDA0003071550200000129
Figure BDA00030715502000001210
specifically, after non-convex constraint is converted into convex constraint through semi-definite relaxation (SDR) to obtain an upper bound of an optimal value of an optimization problem, the first subproblem is converted into a standard convex semi-definite programming problem (SDP), where the optimal value is an upper bound of the original first subproblem, and therefore an approximate solution of the first subproblem is obtained through a gaussian random method.
Further, in step S41, the transmit power is limited
Figure BDA00030715502000001211
In case of (1), take
Figure BDA00030715502000001212
The joint optimization problem will be expressed as
Figure BDA0003071550200000131
Figure BDA0003071550200000132
Figure BDA0003071550200000133
In a similar manner to the first sub-question, the substitution of variables is made
Figure BDA0003071550200000134
Deriving from the joint optimization problem the following second sub-problem:
Figure BDA0003071550200000135
Figure BDA0003071550200000136
Figure BDA0003071550200000137
wherein:
Figure BDA0003071550200000138
Figure BDA0003071550200000139
Figure BDA00030715502000001310
further, similar to the process of solving the first sub-problem, in the step S42, the process of solving the first sub-problem is as follows:
with v H R B v＝tr(R B vv H ),v H R W v＝tr(R W vv H )，V＝vv H After semi-positive relaxation of the constraint term in the second sub-problem, the second sub-problem is adjusted to the form
Figure BDA00030715502000001311
Figure BDA00030715502000001312
Figure BDA00030715502000001313
Figure BDA00030715502000001314
Since the above expression is in a fractional form after adjustment, charnes-Cooper transformation can be adopted to perform
Figure BDA0003071550200000141
And X = mu V, further adjusting the second sub-problem to be in the following form, and then obtaining a second optimal concealment rate by convex optimization solution and Gaussian random method solution:
Figure BDA00030715502000001411
s.t.tr(R W X)+μ|h AW | 2 ＝λ；
Figure BDA0003071550200000143
Figure BDA0003071550200000144
P max ≥μ。
further, in step S43, the optimal combination of the transmission power and the reflection phase
Figure BDA0003071550200000145
Obtained according to the following formula:
Figure BDA0003071550200000146
wherein
Figure BDA0003071550200000147
For the purpose of the first preferred rate of concealment,
Figure BDA0003071550200000148
is the second preferred concealment rate.
As a preferred embodiment, the covert communication model employs a bounded uncertainty model of channel uncertainty and the presence of noise uncertainty at the position of the illegal detector;
the optimal value of the false detection rate threshold lambda of the illegal detector for the communication between the transmitter and the legal receiver is
Figure BDA0003071550200000149
Where p represents the noise uncertainty at the location of the illegal detector,
Figure BDA00030715502000001410
representing an upper noise bound in the noise uncertainty.
Next, a comparison between a simulation experiment and two existing optimization strategies, namely a fixed RIS phase and a fixed transmit power, will be described, and please refer to fig. 4 and 5 for a comparison result of the simulation experiment, where a vertical coordinate is a concealment rate, a horizontal coordinate of fig. 4 is the number of RIS reflection elements, and a horizontal coordinate of fig. 5 is a noise uncertainty; therefore, compared with two existing optimization strategies of a fixed RIS phase and a fixed transmitting power, the concealment rate joint optimization method for the reconfigurable intelligent surface auxiliary communication provided by the embodiment has better improvement on the concealment rate; at the same time, we can also find out from it: as the number of RIS reflection elements increases, the hiding rate of legitimate users will also increase. As the noise uncertainty increases, the concealment rate for legitimate users increases; but with the prior art, the noise uncertainty increases more slowly for the user's concealment rate; for joint optimization, the noise uncertainty has a large influence on the concealment rate of a legal user, the noise uncertainty is increased, and the concealment rate is relatively obviously improved.
Example 2
A joint optimization system for the hidden rate of reconfigurable intelligent surface auxiliary communication refers to FIG. 6, and includes a hidden communication model building module 1, a joint optimization problem building module 2, a channel state information obtaining module 3 and an optimal combination obtaining module 4; the joint optimization problem construction module 2 is connected with the covert communication model construction module 1 and the optimal combination acquisition module 4, and the optimal combination acquisition module 4 is connected with the channel state information acquisition module 3; wherein:
the covert communication model building module 1 is used for building a covert communication model consisting of a transmitter, a legal receiver, an illegal detector and a reconfigurable intelligent surface;
the joint optimization problem construction module 2 is used for constructing a joint optimization problem which takes the transmitting power of the transmitter and the reflection phase of the reconfigurable intelligent surface as variables to be optimized in order to maximize the concealment rate according to the covert communication model;
the channel state information acquisition module 3 is used for acquiring the channel state information among the transmitter, the legal receiver, the illegal detector and the reconfigurable intelligent surface;
and the optimal combination obtaining module 4 is configured to solve the joint optimization problem according to the channel state information to obtain an optimal combination of the transmission power and the reflection phase.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims (7)

1. A joint optimization method for hidden rate of reconfigurable intelligent surface auxiliary communication is characterized by comprising the following steps:
s1, constructing a covert communication model consisting of a transmitter, a legal receiver, an illegal detector and a reconfigurable intelligent surface;
s2, constructing a joint optimization problem which aims to maximize the concealment rate and takes the transmitting power of the transmitter and the reflection phase of the reconfigurable intelligent surface as variables to be optimized according to the covert communication model;
s3, acquiring channel state information among the transmitter, the legal receiver, the illegal detector and the reconfigurable intelligent surface;
s4, solving the joint optimization problem according to the channel state information to obtain the optimal combination of the transmitting power and the reflection phase;
the joint optimization problem is expressed by the following formula:
Figure FDA0003868150660000011
s.t.P a ≤P max ；
Figure FDA0003868150660000012
Figure FDA0003868150660000013
wherein,
Figure FDA0003868150660000014
representing reconfigurabilityReflection phase, P, of smart surface a Denotes the transmission power, h, of the transmitter AB Indicating channel state information between the transmitter and the legitimate receiver, h IB Representing channel state information between reconfigurable smart surface and legitimate receiver, h AI Representing channel state information between a transmitter and a reconfigurable smart surface, P max Denotes the transmit power limit, h, of the transmitter AW Representing channel state information between a transmitter and an illegal detector, lambda represents a false detection rate threshold of the illegal detector for communication between the transmitter and a legal receiver, and N represents the total number of reflecting elements of the reconfigurable intelligent surface;
in the step S4, the following steps are included:
s41, according to the value of the transmitting power, decomposing the joint optimization problem into a first sub-problem and a second sub-problem, wherein only the reflection phase is reserved as a variable to be optimized;
s42, respectively solving the first sub-problem and the second sub-problem to obtain a first optimized concealment rate and a second optimized concealment rate;
s43, calculating the optimal combination of the transmitting power and the reflection phase according to the first preferred concealment rate and the second preferred concealment rate;
in step S41, for transmit power limitation
Figure FDA0003868150660000021
In case of (1), take P a ＝P max By replacement of variables such that
Figure FDA0003868150660000022
Deriving from the joint optimization problem the following first sub-problem:
Figure FDA0003868150660000023
Figure FDA0003868150660000024
Figure FDA0003868150660000025
wherein:
Figure FDA0003868150660000026
Figure FDA0003868150660000027
Figure FDA0003868150660000028
2. the method for jointly optimizing hiding rate for reconfigurable intelligent surface assisted communication according to claim 1, wherein in the step S42, the process of solving the first sub-problem is as follows:
with v H R B v＝tr(R B vv H ),v H R W v＝tr(R W vv H )，V＝vv H And performing semi-positive definite relaxation on a constraint term in the first subproblem, so that the first subproblem is adjusted to be in the following form, and then a first optimal concealment rate is obtained by convex optimization solution and Gaussian random method solution:
Figure FDA0003868150660000029
Figure FDA00038681506600000210
Figure FDA00038681506600000211
Figure FDA00038681506600000212
3. the method for joint optimization of hidden rate for reconfigurable intelligent surface-assisted communication according to claim 1, wherein in step S41, the transmit power is limited
Figure FDA00038681506600000213
In case of (1), take
Figure FDA0003868150660000031
By replacement of variables such that
Figure FDA0003868150660000032
Deriving from the joint optimization problem the following second sub-problem:
Figure FDA0003868150660000033
Figure FDA0003868150660000034
Figure FDA0003868150660000035
wherein:
Figure FDA0003868150660000036
Figure FDA0003868150660000037
Figure FDA0003868150660000038
4. the method for jointly optimizing hidden rate of reconfigurable intelligent surface-assisted communication according to claim 3, wherein in step S42, the process of solving the second sub-problem is as follows:
with v is H R B v＝tr(R B vv H ),v H R W v＝tr(R W vv H )，V＝vv H After semi-positive definite relaxation of the constraint term in the second subproblem, to
Figure FDA0003868150660000039
And X = mu V, so that the second sub-problem is adjusted to the following form, and then a second optimal concealment rate is obtained by convex optimization solution and Gaussian random method solution:
Figure FDA00038681506600000310
s.t.tr(R W X)+μ|h AW | 2 ＝λ；
Figure FDA00038681506600000311
Figure FDA00038681506600000312
P max ≥μ。
5. the joint optimization method for covert rate of reconfigurable intelligent surface assisted communication (RSC) of any one of claims 1 to 4, wherein in step S43, the optimal combination of transmission power and reflection phase
Figure FDA0003868150660000041
Obtained according to the following formula:
Figure FDA0003868150660000042
wherein
Figure FDA0003868150660000043
For the purpose of the first preferred rate of concealment,
Figure FDA0003868150660000044
is the second preferred concealment rate.
6. The joint optimization method for concealment rate of reconfigurable intelligent surface auxiliary communication according to any one of claims 1 to 4, characterized in that:
the covert communication model adopts a bounded uncertainty model with uncertain channels and noise uncertainty at the position of the illegal detector;
the optimal value of the false detection rate threshold lambda of the illegal detector for the communication between the transmitter and the legal receiver is
Figure FDA0003868150660000045
Where p represents the noise uncertainty at the location of the illegal detector,
Figure FDA0003868150660000046
representing an upper noise bound in the noise uncertainty.
7. A hidden rate joint optimization system for reconfigurable intelligent surface auxiliary communication is characterized by comprising a hidden communication model building module (1), a joint optimization problem building module (2), a channel state information acquisition module (3) and an optimal combination acquisition module (4); the joint optimization problem construction module (2) is connected with the covert communication model construction module (1) and the optimal combination acquisition module (4), and the optimal combination acquisition module (4) is connected with the channel state information acquisition module (3); wherein:
the covert communication model building module (1) is used for building a covert communication model consisting of a transmitter, a legal receiver, an illegal detector and a reconfigurable intelligent surface;
the joint optimization problem construction module (2) is used for constructing a joint optimization problem which takes the transmitting power of the transmitter and the reflection phase of the reconfigurable intelligent surface as variables to be optimized for the purpose of maximizing the concealment rate according to the covert communication model;
the channel state information acquisition module (3) is used for acquiring the channel state information among the transmitter, the legal receiver, the illegal detector and the reconfigurable intelligent surface;
the optimal combination obtaining module (4) is used for solving the joint optimization problem according to the channel state information to obtain the optimal combination of the transmitting power and the reflection phase;
the joint optimization problem is expressed by the following formula:
Figure FDA0003868150660000047
s.t.P a ≤P max ；
Figure FDA0003868150660000051
Figure FDA0003868150660000052
wherein,
Figure FDA0003868150660000053
representing the reflected phase, P, of a reconfigurable smart surface a Denotes the transmission power, h, of the transmitter AB Indicating channel state information between the transmitter and the legitimate receiver, h IB Representing channel state information between reconfigurable smart surface and legitimate receiver, h AI Representing channel state information between a transmitter and a reconfigurable smart surface, P max Denotes the transmit power limit, h, of the transmitter AW Representing channel state information between a transmitter and an illegal detector, lambda represents a false detection rate threshold of the illegal detector for communication between the transmitter and a legal receiver, and N represents the total number of reflecting elements of the reconfigurable intelligent surface;
in the optimal combination obtaining module (4), the following processing steps are included:
s41, decomposing the joint optimization problem into a first sub-problem and a second sub-problem which only reserve a reflection phase as a variable to be optimized according to the value of the transmitting power;
s42, respectively solving the first sub-problem and the second sub-problem to obtain a first optimized concealment rate and a second optimized concealment rate;
s43, calculating the optimal combination of the transmitting power and the reflection phase according to the first optimal concealment rate and the second optimal concealment rate;
in step S41, for transmit power limitation
Figure FDA0003868150660000054
In case of (1), take P a ＝P max By replacement of variables such that
Figure FDA0003868150660000055
Deriving from the joint optimization problem the following first sub-problem:
Figure FDA0003868150660000056
Figure FDA0003868150660000057
Figure FDA0003868150660000058
wherein:
Figure FDA0003868150660000059
Figure FDA00038681506600000510
Figure FDA0003868150660000061
CN202110540961.1A 2021-05-18 2021-05-18 Combined optimization method and system for hidden rate of reconfigurable intelligent surface auxiliary communication Active CN113286292B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110540961.1A CN113286292B (en) 2021-05-18 2021-05-18 Combined optimization method and system for hidden rate of reconfigurable intelligent surface auxiliary communication

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110540961.1A CN113286292B (en) 2021-05-18 2021-05-18 Combined optimization method and system for hidden rate of reconfigurable intelligent surface auxiliary communication

Publications (2)

Publication Number Publication Date
CN113286292A CN113286292A (en) 2021-08-20
CN113286292B true CN113286292B (en) 2022-11-22

Family

ID=77279719

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110540961.1A Active CN113286292B (en) 2021-05-18 2021-05-18 Combined optimization method and system for hidden rate of reconfigurable intelligent surface auxiliary communication

Country Status (1)

Country Link
CN (1) CN113286292B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11848709B2 (en) * 2020-08-14 2023-12-19 Huawei Technologies Co., Ltd. Media-based reconfigurable intelligent surface-assisted modulation
CN118054977B (en) * 2024-04-16 2024-06-28 昆明学院 Hybrid mode-based joint concealment and secure communication system and method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111181615A (en) * 2019-11-29 2020-05-19 广东工业大学 Multi-cell wireless communication method based on intelligent reflector
CN112073107A (en) * 2020-09-17 2020-12-11 南通大学 Multi-group and multicast combined beam forming algorithm design based on intelligent reflecting surface
CN112260740A (en) * 2020-10-19 2021-01-22 电子科技大学 Reconfigurable intelligent surface-assisted symbiotic communication system beam forming design method
CN112804695A (en) * 2020-12-28 2021-05-14 北京邮电大学 Reconfigurable intelligent surface-assisted wireless communication method and device

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9780859B2 (en) * 2014-02-28 2017-10-03 Spatial Digital Systems, Inc. Multi-user MIMO via active scattering platforms
CN111355520B (en) * 2020-03-10 2022-03-08 电子科技大学 Design method of intelligent reflection surface assisted terahertz safety communication system
CN111447618B (en) * 2020-03-13 2022-07-22 重庆邮电大学 Intelligent reflector energy efficiency maximum resource allocation method based on secure communication
CN111901802B (en) * 2020-07-31 2023-02-14 东南大学 MISO system downlink secrecy rate optimization method by means of intelligent reflection surface
CN112383332B (en) * 2020-11-03 2021-08-24 电子科技大学 Honeycomb base station communication system based on intelligent reflection surface

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111181615A (en) * 2019-11-29 2020-05-19 广东工业大学 Multi-cell wireless communication method based on intelligent reflector
CN112073107A (en) * 2020-09-17 2020-12-11 南通大学 Multi-group and multicast combined beam forming algorithm design based on intelligent reflecting surface
CN112260740A (en) * 2020-10-19 2021-01-22 电子科技大学 Reconfigurable intelligent surface-assisted symbiotic communication system beam forming design method
CN112804695A (en) * 2020-12-28 2021-05-14 北京邮电大学 Reconfigurable intelligent surface-assisted wireless communication method and device

Also Published As

Publication number Publication date
CN113286292A (en) 2021-08-20

Similar Documents

Publication Publication Date Title
CN113286292B (en) Combined optimization method and system for hidden rate of reconfigurable intelligent surface auxiliary communication
CN102362435B (en) Device and method for cooperative spectrum sensing in cognitive radio systems
CN112911586B (en) Method and system for realizing covert communication based on intelligent reflector
US9161214B2 (en) Wireless communication method and system for transmission authentication at the physical layer
US20100246825A1 (en) Wireless communication method and system for transmission authentication at the physical layer
CN111328079B (en) Multi-antenna hidden communication method for movable eavesdropper
Leu et al. Message time of arrival codes: A fundamental primitive for secure distance measurement
Liu et al. Covert ambient backscatter communications with multi-antenna tag
CN112954672B (en) Unmanned aerial vehicle relay covert communication method for flight monitoring person
CN110730452A (en) Performance analysis method of combined relay and interference selection scheme in wireless communication system
CN112383380A (en) Covert vehicle communication method based on non-orthogonal multiple access technology
CN114520972A (en) Interference-assisted covert wireless communication method in multi-channel system
CN114205048A (en) Wireless single-input single-output vector synthesis safe transmission method based on RIS
Bu et al. Fast cloned-tag identification protocols for large-scale RFID systems
CN109348503A (en) A kind of monitor method of wireless communication link, device, equipment and system
EP3574666A1 (en) Secure near field communications
US20210099863A1 (en) Dynamic data sequence puncturing
CN116073866B (en) RIS auxiliary MIMO is a hidden communication method of (a)
CN109996231A (en) A kind of secret communication method in multiaerial system
CN114142909B (en) Passive radar assisted physical layer safety satellite communication method
Huo et al. A framework to securing RFID transmissions by varying transmitted reader's power
CN114531674A (en) Combined secrecy and covert communication method and system based on rate segmentation
Yang et al. Physical Layer Authentication in Backscatter Communication: A Review
JP4848949B2 (en) Authentication apparatus, authentication method, and program
Xu et al. Covert and reliable semantic communication against cross-layer privacy inference over wireless edge networks

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant