CN110300409A - Limited piece long covert communications implementation method based on channel estimation - Google Patents

Limited piece long covert communications implementation method based on channel estimation Download PDF

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Publication number
CN110300409A
CN110300409A CN201910419695.XA CN201910419695A CN110300409A CN 110300409 A CN110300409 A CN 110300409A CN 201910419695 A CN201910419695 A CN 201910419695A CN 110300409 A CN110300409 A CN 110300409A
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channel
estimation
probability
false
covert communications
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CN110300409B (en
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束锋
徐婷珍
唐钰城
胡锦松
颜世豪
桂林卿
徐玲
刘笑语
陆造宇
钱玉文
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Nanjing University of Science and Technology
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Nanjing University of Science and Technology
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/024—Channel estimation channel estimation algorithms
    • H04L25/0256—Channel estimation using minimum mean square error criteria
    • 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]
    • 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

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

Abstract

The long covert communications implementation method of limited piece that the present invention provides a kind of based on channel estimation.Channel, which is known, all to be assumed that for the research of covert communications in fading channel in the past, or Poewr control method is inverted to avoid the estimation of channel by channel.However in practice, due to the desirability that channel reciprocity is assumed, channel estimation is inevitably carried out in fading channel.In traditional channel estimation, optimal pilot number is equal to transmission antenna number, but in covert communications, which may no longer be set up.In order to improve the reliability of covert communications, we estimate channel using Minimum Mean Squared Error estimation method, design optimal number of pilots and transmission power, data number and transmission power under hidden constraint condition to maximize effective speed.At the same time, due to previous studies be typically all concentrate on the long analysis of unlimited block, but usually to send limited piece of long symbol in practice, therefore the present invention study it is limited piece long under covert communications.

Description

Limited piece long covert communications implementation method based on channel estimation
Technical field
The present invention relates to wireless communication technology fields, in particular to the long covert communications of limited piece based on channel estimation are realized Method.
Background technique
With the rapid development of mobile communication, the privacy of information transmission is protected to become more and more important.However it is traditional In the method for ensuring information security property, often information content itself is protected, for example is encrypted.But it is easy to allow surreptitiously in this way Hearer knows is transmitting secret information at this time, can be easier the interest of excitation listener-in's decryption.
The purpose of covert communications is exactly the process of hiding information transmission, and guarder is allowed not know the hair for having information transport behavior It is raw, that is, ensure that guarder detects information with very low detection probability and transmitting.In the past for covert communications in fading channel In research all assume that channel is known, or using the reciprocity of channel, invert Poewr control method with channel and keep away Exempt from the estimation to channel.However in practice, the hypothesis of channel reciprocity is excessively ideal, this is not it is avoided that estimate channel Meter.At the same time, most of that unlimited block is long all to be assumed that for the research of covert communications, but generally require to send in practice to have Limit the long symbol of block.Therefore, for these problems, limited piece long covert communications of the present invention research based on channel estimation, hidden The power allocation factor constrained down between optimizing pilot number and pilot tone and data is covered to maximize effective speed, is had very deep Remote meaning and important theoretical research value and application prospect.
Summary of the invention
The technical problem to be solved by the present invention is to be directed to the limited piece of long convert communication system containing channel estimation errors, Provide that a kind of how to optimize based on channel estimation sends the side of pilot number and power allocation factor to maximize effective speed Method effectively improves the reliability and concealment of system.
The present invention uses following technical scheme to solve above-mentioned technical problem: a kind of limited piece based on channel estimation long hidden Cover Realization Method of Communication, comprising:
It and include evaluated error since channel gain is obtained by estimation, then we need according to estimating To channel acquire the expression formula of effective speed；
Considering that the first situation is is rayleigh fading channel between transmitting terminal and recipient, and between transmitting terminal and guarder For Gaussian channel, i.e., the worst situation is considered from transmitting terminal.Consider second more typically property the case where, i.e. transmitting terminal and reception It is all fading channel between end, transmitting terminal and guarder.The false-alarm and false dismissal probability of guarder in the case of calculating separately two kinds；
Obtain optimal power allocation factor η and pilot number np, it generally will be by two-dimensional search, but we are according to excellent A kind of linear search method with two-dimensional search matched of the feature extraction of change problem；
As one embodiment, the consideration acquires effective speed expression formula according to channel estimation, comprising:
Step 11) assumes initially that using MMSE estimator, then the channel between transmitting terminal Alice and receiving end Bob can be with It is expressed as
WhereinTo estimate channel,For evaluated error, E [| hab|2]=λab, npAnd ρpIt respectively indicates pilot number and is averaged Pilot symbol power,For the noise power at the end Bob,WithPower be denoted as respectivelyWith
Step 12), in decoding stage, receiving data can be expressed as BobIts Middle xdIndicate data symbol, ρdIndicate average data symbol power, nbFor the additive Gaussian noise of Bob.By evaluated error and noise It is considered as interference n simultaneouslyb', then the effective signal-to-noise ratio of Bob be
The power accounting that data are distributed to from general power is denoted as η, the portion remaining 1- η for simplifying the analysis by step 13) Distribute to pilot tone, i.e. ρdnd=η ρ n, ρpnp=(1- η) ρ n, 0 < η < 1, wherein ρ indicates average symbol power, and n indicates total symbol Number, i.e. np+nd=n, ndFor data symbols number.Then the effective signal-to-noise ratio of Bob can be with abbreviationEffective speed is
As one embodiment, the false-alarm for calculating separately guarder in both cases and false dismissal probability, comprising:
Step 21) works as ρ in the channel Gaussian distributed of Alice-Williep=ρdWhen=ρ, false-alarm probability ForFalse dismissal probability isWherein τ is the detection threshold of guarder Willie.Enable mistake Probability ξ=alpha+beta minimizes, and the optimal detection thresholding for then obtaining guarder isIt is corresponding Optimal error probability is ξ*, ξ*>=1- ∈ is as hidden constraint condition.
Step 22) works as ρ in Gaussian channelp≠ρdWhen, according to the strong law of large number and when pilot number is smaller, Willie Average received symbol power can be approximated to be Then false dismissal probability isFalse-alarm probability is constant, obtains optimal detection thresholding and isObtain optimal error probability ξ*。
Step 23) works as ρ in the channel Rayleigh distributed of Alice-Williep=ρdWhen=ρ, be easy to get the feelings Optimal error probability ξ under condition*With ρ in Gaussian channelp=ρdExpression formula in the case of=ρ is identical.
Step 24) works as ρ in Rayleigh channelp≠ρdWhen, according to Markov inequality, acquire the approximate expression of missing inspection Formula isThen obtaining optimal detection thresholding is
As one embodiment, a kind of linear search method that pinpoint accuracy is proposed according to optimization problem, comprising:
Step 31), initiation parameter n, ρ,∈,λab。
Step 32) solves ξ for each η*=1- ∈ obtains n optimal under fixed ηp, it is denoted as
Step 33), take away fromTwo nearest integers, are denoted asWithξ is substituted into respectively*Expression formula obtainWithIfIt enablesOtherwise it enables?Effective speed expression formula is substituted into obtain
Step 34), it is more allMaximum value is searched for, global optimum is obtainedAnd C*。
The invention adopts the above technical scheme compared with prior art, has following technical effect that
The long covert communications implementation method of limited piece based on channel estimation proposed considers the channel estimation comprising error Inside, pilot number and power allocation factor are optimized according to the channel that estimation obtains, it is more direct than in general fading channel Assuming that the research that channel is known covert communications is more of practical significance, performance is also improved.And the present invention is mentioned Linear search algorithm greatly reduce the complexity of algorithm.
The additional aspect of the present invention and advantage will be set forth in part in the description, these will become from the following description Obviously, or practice through the invention is recognized.
Detailed description of the invention
Fig. 1 shows the limited piece long covert communications implementation method flow chart based on channel estimation.
Fig. 2 shows linear search algorithms and two-dimentional algorithm simulating result.
Fig. 3 shows the optimal effective speed that the method for the present invention obtains and existing channel reversion power control (CIPC) side The simulation result of method.
Specific embodiment
In the following with reference to the drawings and specific embodiments, the present invention is furture elucidated, it should be understood that these embodiments are merely to illustrate It the present invention rather than limits the scope of the invention, after the present invention has been read, those skilled in the art are to of the invention each The modification of kind equivalent form falls within the application range as defined in the appended claims.
A kind of limited piece long covert communications implementation method based on channel estimation of the invention includes: first to obtain guarder's Optimal error probability enables it be greater than some and then maximizes effective speed as shelter condition close to 1 number and led with optimizing Frequency and power allocation factor.
As one embodiment, which comprises there are in the case where channel estimation errors, first acquire having for receiving end Imitate rate.Acquire the false-alarm and false dismissal probability of guarder in gaussian sum Rayleigh channel respectively again.In the item for meeting hidden constraint Under part, for the optimal transmission pilot number of objective function optimization and power allocation factor.
Step 1: assuming that Alice sends n symbol simultaneously in one time slot, including npA pilot tone (average symbol Transmission power is ρp) and nd(it is ρ that average symbol sends power to a datad).Assuming that using MMSE estimation method, then Alice-Bob Between channel can be expressed as estimation the sum of channel and evaluated errorThus the effective signal-to-noise ratio of Bob is released ForWherein, E [| hab|2]=λab,For the noise power at the end Bob
Step 2: since there are four Optimal Parameters, pilot number npWith power ρp, pilot number ndWith power ρd, for simplification Analysis introduces power allocation factor η, i.e. ρdnd=η ρ n, ρpnp=(1- η) ρ n, 0 < η < 1, wherein ρ indicates average symbol power. Then the effective signal-to-noise ratio of Bob can simplify forEffective speed is
Step 3: the channel between Alice-Bob is fading channel, the channel between Alice-Willie is Gauss letter In the case where road, acquires and work as ρp=ρdThe false-alarm and false dismissal probability of Willie when=ρ, and acquire optimal detection thresholding and beObtain corresponding optimal error probability ξ*, whereinFor the noise power of Willie.It is similar ρ is worked as on groundp≠ρdWhen, the optimal detection thresholding for acquiring Willie isWherein Γ () expression Gamma function, W (k, X) k-th of branch for indicating Lambert W function, that is, give about x=tetSolution t.
Step 4: acquiring and working as in the case that the channel between Alice-Bob and Alice-Willie is all fading channel ρp=ρdWhen=ρ, the case where optimal detection thresholding of Willie is distributed with Gaussian channel mid power, is identical.Work as ρp≠ρdWhen, root According to Markov inequality, the approximate expression for acquiring missing inspection is Then obtaining optimal detection thresholding isIt obtains simultaneously corresponding ξ*。
Step 5: for the above various situations, in hidden constraint ξ*Under >=1- ∈, pilot number and power distribution is separately optimized Factor η.Algorithm mainly comprises the following steps, and for each η, solves ξ*=1- ∈ obtains n optimal under fixed ηp, it is denoted asTake away from Two nearest integers, are denoted asWithξ is substituted into respectively*Expression formula obtainWithIfIt enables Otherwise it enables?Effective speed expression formula is substituted into obtainCompare allMaximum value is searched for, obtains the overall situation most ExcellentAnd C*。
The linear search algorithm shown from Fig. 2 and two-dimentional algorithm simulating result, it can be seen that the algorithm has very high Accuracy, and greatly reduce the complexity of algorithm.Fig. 3 depicts the optimal effective speed that the method for the present invention obtains and existing Channel reversion power control (CIPC) method comparison, to find out in the case where limited piece is long, with the increase of the long n of block, mentioned side Method performance is substantially better than CIPC.
Covert communications implementation method proposed by the present invention limited piece long based on channel estimation, performance are better than existing channel Poewr control method is inverted, and the linear search algorithm proposed significantly reduces complexity, realizes the good of performance and complexity Good tradeoff, improves the reliability of covert communications.

Claims (2)

1. a kind of limited piece long covert communications implementation method based on channel estimation characterized by comprising
Since channel gain is obtained by estimation, and includes evaluated error, then need the channel obtained according to estimation Acquire the expression formula of effective speed；
Considering that the first situation is is rayleigh fading channel between transmitting terminal and recipient, and is high between transmitting terminal and guarder This channel considers the worst situation from transmitting terminal.Consider second more typically property the case where, i.e. transmitting terminal and receiving end, hair It is all fading channel between sending end and guarder.The false-alarm and false dismissal probability of guarder in the case of calculating separately two kinds；
Obtain optimal power allocation factor η and pilot number np, it generally will be by two-dimensional search, but we ask according to optimization A kind of linear search method with two-dimensional search matched of the feature extraction of topic；
The consideration acquires effective speed expression formula according to channel estimation, comprising:
Step 11) assumes initially that then the channel between transmitting terminal Alice and receiving end Bob can indicate using MMSE estimator For
WhereinTo estimate channel,For evaluated error, E [| hab|2]=λab, npAnd ρpRespectively indicate pilot number and average pilot Symbol power,For the noise power at the end Bob,WithPower be denoted as respectivelyWith
Step 12), in decoding stage, receiving data can be expressed as BobWherein xd Indicate data symbol, ρdIndicate average data symbol power, nbFor the additive Gaussian noise of Bob.Simultaneously by evaluated error and noise It is considered as interference nb', then the effective signal-to-noise ratio of Bob be
Step 13) introduces power allocation factor η, i.e. ρ for simplifying the analysisdnd=η ρ n, ρpnp=(1- η) ρ n, 0 < η < 1, wherein ρ indicates average symbol power, and n indicates total symbolic number, i.e. np+nd=n, ndFor data symbols number.Then the effective signal-to-noise ratio of Bob Can be with abbreviationEffective speed is
2. the method according to claim 1, wherein the false-alarm for calculating separately guarder in both cases And false dismissal probability, comprising:
Step 21) works as ρ in the channel Gaussian distributed of Alice-Williep=ρdWhen=ρ, false-alarm probability α is acquired With false dismissal probability β.Error probability ξ=alpha+beta is enabled to minimize, the optimal detection thresholding for then obtaining guarder isCorresponding optimal error probability is ξ*, ξ*>=1- ∈ as hidden constraint condition, wherein ∈ is an arbitrarily small positive number.
Step 22) works as ρ in Gaussian channelp≠ρdWhen, according to the strong law of large number and when pilot number is smaller, Willie's is flat Receiving symbol power can be approximated to beThen False dismissal probability isFalse-alarm probability is constant, obtains optimal detection thresholding and isObtain optimal error probability ξ*.Wherein W (k, X) k-th of branch for indicating Lambert W function, that is, give about x=tetSolution t, Γ () indicate Gamma function.
Step 23) works as ρ in the channel Rayleigh distributed of Alice-Williep=ρdWhen=ρ, it is easy to get in this case Optimal error probability ξ*With ρ in Gaussian channelp=ρdExpression formula in the case of=ρ is identical.
Step 24) works as ρ in Rayleigh channelp≠ρdWhen, according to Markov inequality, the approximate expression for acquiring missing inspection isWherein θ is a sufficiently small positive number,Indicate expectation.In It is to obtain optimal detection thresholding to be
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112954672A (en) * 2021-02-09 2021-06-11 大连理工大学 Unmanned aerial vehicle relay covert communication method for flight monitoring person
CN113746803A (en) * 2021-08-02 2021-12-03 西安电子科技大学 Covert communication method, system, computer equipment and processing terminal

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101523796A (en) * 2006-10-12 2009-09-02 交互数字技术公司 A method and system for enhancing cryptographic capabilities of a wireless device using broadcasted random noise
CN109474367A (en) * 2018-12-10 2019-03-15 南京理工大学 Low time delay covert communications implementation method based on full duplex receiver
CN109714737A (en) * 2019-02-21 2019-05-03 江苏大学 A kind of D2D convert communication system and its communication means with full duplex base station cellular network

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101523796A (en) * 2006-10-12 2009-09-02 交互数字技术公司 A method and system for enhancing cryptographic capabilities of a wireless device using broadcasted random noise
CN109474367A (en) * 2018-12-10 2019-03-15 南京理工大学 Low time delay covert communications implementation method based on full duplex receiver
CN109714737A (en) * 2019-02-21 2019-05-03 江苏大学 A kind of D2D convert communication system and its communication means with full duplex base station cellular network

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
TINGZHEN XU 等: "Covert Communication with A Full-Duplex Receiver Based on Channel Distribution Information", 《IEEE》 *
TINGZHEN XU 等: "Pilot-Based Channel Estimation Design in Covert Wireless Communication", 《HTTP://ARXIV.ORG/ABS/1908.00226》 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112954672A (en) * 2021-02-09 2021-06-11 大连理工大学 Unmanned aerial vehicle relay covert communication method for flight monitoring person
CN112954672B (en) * 2021-02-09 2022-09-23 大连理工大学 Unmanned aerial vehicle relay covert communication method for flight monitoring person
CN113746803A (en) * 2021-08-02 2021-12-03 西安电子科技大学 Covert communication method, system, computer equipment and processing terminal

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