A network system combining security and energy load balancing

Abstract

The present invention discloses a network system combining security and energy load balancing, comprising: Access Points (APs): equipped with N t antennas, with L APs included. The APs are connected to the CPU through wired backhaul links. All APs serve K single-antenna User Equipments (UEs). All APs are equipped with independent Edge Servers (ESs) and form APs-ESs equipped with independent edge servers; Single-antenna attacker Eve: used to intercept legitimate information; The working mode of the APs-ESs and the attacker Eve is the full-duplex mode. The attacker Eve intercepts the uplink transmission through passive eavesdropping and intercepts the downlink transmission through active pilot contamination attacks. The APs-ESs send artificial noise signals to the attacker Eve during the uplink task offloading transmission process to resist passive eavesdropping.

Description

Technical Field

[0001] The present invention relates to the field of data security transmission, and in particular to a network system combining security and energy load balancing. Background Art

[0002] At present, the research on computational offloading in the non-cellular massive MIMO (multiple input multiple output) architecture mainly focuses on three aspects: energy consumption minimization, latency optimization, and computational resource allocation. These works are all dedicated to solving the problem of how to ensure the QoS (quality of service) of UE (user terminal) in load calculation, and the load balancing performance of edge servers in the network is not fully considered. The load imbalance of edge servers will significantly affect the service quality and reduce the service life of edge servers.

[0003] In the non-cellular massive MIMO scenario, data security threats are a key issue in the task offloading process. Considering the significant directional gain enhancement brought by massive MIMO, it is feasible to achieve high-precision beamforming in the non-cellular massive MIMO scenario. However, active eavesdroppers can send spoofed pilot sequences to reduce the downlink beamforming accuracy, which is called PCA (pilot pollution attack). As a supplement to traditional cryptography, PLS (physical layer security) aims to exploit the characteristics and defects of wireless channels, including noise, fading, interference, dispersion, and diversity. Therefore, to solve this problem, PLS technology has gradually become one of the key technologies to resist active Eve. In addition, to counter the passive eavesdropping of Eve, existing research mainly focuses on CJ (cooperative interference). This technology involves deploying a friendly jammer to selectively interfere with Eve (attacker), thereby preventing data leakage by transmitting interference signals targeting Eve. Although physical layer security transmission has been well studied, the simultaneous guarantee of joint transmission of uplink and downlink for computational offloading in non-cellular massive MIMO networks has not been fully studied. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a network system combining security and energy load balancing, which is an efficient and secure transmission solution that can simultaneously resist uplink passive eavesdropping and downlink pilot pollution attacks.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] A network system combining security and energy load balancing is provided, comprising:

[0007] Access point AP: equipped with N tantennas, the access point AP includes L access points, the access point AP is connected to the CPU through a wired backhaul link, all access points AP serve K single-antenna user terminals UE, all access points AP are equipped with independent edge servers ES, and form access point AP-ES equipped with independent edge servers;

[0008] Single-antenna attacker Eve: used to intercept legitimate information;

[0009] All access points AP-ES, user terminals UE and attacker Eve are randomly distributed in the coverage area, and L>>K. The set of access points AP-ES is A={1,2,…,l,…,L}, where l is the number of the access point AP-ES, and the set of user terminals UE is U={1,2,…,k,…,K}, where k is the number of the user terminal UE.

[0010] The access point AP-ES and the attacker Eve work in full-duplex mode. The attacker Eve intercepts uplink transmission through passive eavesdropping and intercepts downlink transmission through active pilot pollution attack. The access point AP-ES sends artificial noise signals to the attacker Eve during the uplink task offloading transmission to resist passive eavesdropping.

[0011] Furthermore, the method for the access point AP-ES, the attacker Eve, and the user terminal UE to perform data transmission within the coverage area is as follows:

[0012] S1: Each user terminal UE first sends the assigned pilot sequence to the access point AP-ES;

[0013] S2: The access point AP-ES determines whether the user terminal UE is under attack by detecting abnormal pilot signals;

[0014] S3: If the user terminal UE is not attacked by the attacker Eve, it is marked as a normal user terminal UE, otherwise, it is marked as an attacked user terminal UE;

[0015] For the attacked user terminal UE, the access point AP-ES determines whether the arrival angle AOA interval between the user terminal UE and the attacker Eve meets the security transmission condition; if so, the access point AP-ES maintains the connection with the user terminal UE, otherwise, the access point AP-ES disconnects the connection with the user terminal UE;

[0016] S4: The user terminal UE loads system information from the access point AP-ES, and then calculates the achievable confidential transmission rate of uplink transmission and downlink transmission. The user terminal UE makes a task offloading decision based on the access point AP-ES and its current matching status;

[0017] S5: Each access point AP-ES reports its current load to the CPU according to the amount of calculation offloaded from the optimal task offloading decision made by the user terminal UE;

[0018] S6: The CPU calculates the energy-based load imbalance and feeds it back to each access point AP-ES; based on the current load imbalance, each access point AP-ES decides whether to provide services to the user terminal UE, forming the optimal access point AP-ES service selection strategy H * ;

[0019] S7: The user terminal UE estimates the channel state information of the uplink transmission and transmits the offload data in the task offloading decision through the uplink confidentiality transmission rate sent to the corresponding access point AP-ES; at the same time, the access point AP-ES uses the optimal interference strategy J * Send jamming signals to the attacker Eve;

[0020] S8: Afterwards, the access point AP-ES transmits the post-processed data to the user terminal UE through the beamforming technology.

[0021] Furthermore, the gain of a single antenna of the access point AP-ES during data transmission is:

[0022]

[0023] Among them, θ li is the arrival angle from the lth access point AP-ES to the attacker Eve or the user terminal UE, is the beam width of the beam formed at the access point AP-ES, g s is the sidelobe gain, 0 <g s <1,g m is the main lobe gain, i∈{k,e}, e is the number of the attacker Eve, i is the number of the attacker Eve or the user terminal UE, α(θ li ) is the steering vector from the lth access point AP-ES to the user terminal UE or the attacker Eve;

[0024]

[0025] Where, d is the antenna distance between access points AP-ES, and λ is the signal wavelength.

[0026] Furthermore, the channel model between the lth access point AP-ES and the kth user terminal UE is:

[0027]

[0028] Among them, h lkis the channel between the access point AP-ES and the user terminal UE, is the linear space of the channel in the complex field, β lk is the large-scale fading coefficient of the channel between the access point AP-ES and the user terminal UE, is the small-scale fading coefficient of the channel between the access point AP-ES and the user terminal UE, α(θ lk ) is the steering vector from the lth access point AP-ES to the kth user terminal UE, θ lk is the arrival angle from the lth access point AP-ES to the kth user terminal UE;

[0029] The channel model between the lth access point AP-ES and the attacker Eve is:

[0030]

[0031] Among them, h le is the channel between the lth access point AP-ES and the eth attacker Eve, β le is the large-scale fading coefficient of the channel between the lth access point AP-ES and the eth access point Eve, is the small-scale fading coefficient of the channel between the lth access point AP-ES and the eth access point Eve, α(θ le ) is the steering vector from the lth access point AP-ES to the eth attacker Eve, θ le is the arrival angle from the lth access point AP-ES to the eth user terminal UE;

[0032] The channel model between the jth user terminal UE and the eth attacker Eve is:

[0033]

[0034] Among them, h je is the channel between the user terminal UE and the attacker Eve, β je is the large-scale fading coefficient of the channel between the j-th user terminal UE and the e-th attacker Eve, is the small-scale fading coefficient of the channel between the j-th user terminal UE and the e-th attacker Eve.

[0035] Furthermore, the link training process for uplink transmission is:

[0036] The user terminal UE sends the assigned pilot sequence to the access point AP-ES through the uplink channel. The access point AP-ES obtains the estimated downlink channel state information through channel reciprocity in the time division duplex mode for data precoding and data transmission;

[0037] The pilot sequence information received by the access point AP-ES is:

[0038]

[0039] Among them, Y Al is the pilot sequence information received by the lth access point AP-ES, U p ={1,2,…,P},U p is the user terminal UE subset that is attacked by the attacker Eve during the link training process of uplink transmission, j is the number of the user terminal UE in the user terminal UE subset, n l is the additive Gaussian white noise at the position of the lth access point AP-ES, and n l ~CN(0,I), I is the unit matrix, -CN(0,I) represents additive Gaussian white noise n l The complex random variable formed obeys a zero-mean cyclic symmetric complex Gaussian distribution, τ is the length of the normalized mutually orthogonal pilot sequence, P p is the average power of the user terminal UE transmitting the pilot sequence to the access point AP-ES, P e Intercept pilot sequence for Eve The average power sent to the access point AP-ES, is a normalized mutually orthogonal pilot sequence sent by the k-th user terminal UE to the access point AP-ES, is the pilot sequence of the jth user terminal UE intercepted by the attacker Eve, The legal pilot sequence information received by the access point AP-ES. It is the active pilot pollution attack information of the attacker Eve;

[0040] After receiving the pilot sequence information of the user terminal UE, the access point AP-ES detects the abnormal pilot sequence information that may be attacked by the attacker Eve, and sends the abnormal pilot sequence information Y Al Project to The estimated channel state information is obtained by using the least square method;

[0041]

[0042] in, is the estimated channel state information, Pilot sequence The conjugate transpose of .

[0043] Furthermore, the task offloading process of uplink transmission is as follows:

[0044] After the link training process of uplink transmission is completed, an access point subset is established in which the kth user terminal UE is connected to multiple access points AP-ES L′≤L, a subset of user terminals UE associated with the access point AP-ES K′≤K, for task offloading;

[0045] When the user terminal UE offloads the task to the corresponding access point AP-ES, the access point AP-ES simultaneously emits an artificial noise signal to resist the passive eavesdropping of the attacker Eve; the matching matrix H = L × K is used to represent the association between any user terminal and any access point, and the elements in the matching matrix H are expressed as;

[0046]

[0047] Among them, η lk For user terminal U k With access point A l Associated elements, user terminal U k With access point A l When associated, η lk =1, otherwise, η lk =0;

[0048] Subset Access point A in c From the subset User terminal U k Received signal for:

[0049]

[0050] Among them, x k For user terminal U k The transmitted signal, Ε{x k 2}=1,n c Access point A c The additive Gaussian white noise of P t k For user terminal U k The transmission power, v is the artificial noise vector, z is the additive Gaussian white noise signal, and is the power of artificial noise emitted by the lth access point AP-ES, v H is the conjugate transpose of vector v, μ c is the residual self-interference coefficient, indicating the self-interference performance, H is the self-interference channel matrix, η ck For user terminal U k With access point A c The associated element, h ckFor user terminal U k With access point A c The channel between

[0051] Access point A for uplink transmission c Signal-to-noise ratio for:

[0052]

[0053] Among them, σ c Access point A c The standard deviation of the additive Gaussian white noise at H is the conjugate transpose of the self-interference channel matrix;

[0054] The attacker Eve receives the data from the user terminal U k The signal for:

[0055]

[0056] Among them, h ke For user terminal U k The channel between the attacker Eve, m le Access point A l The associated element with the attacker Eve, n e is the additive Gaussian white noise of the attacker Eve, k∈[1,P],σ e is the standard deviation of the additive Gaussian white noise at the attacker Eve;

[0057] The interference strategy of access point AP-ES is defined as a matching matrix J = L × 1, which represents the association between access point AP-ES and attacker Eve. The element m of the matching matrix J is le for:

[0058]

[0059] If access point A l Send an artificial noise signal to the attacker Eve, then m le =1, otherwise, m le =0;

[0060] The signal-to-noise ratio of the attacker Eve in the uplink transmission for:

[0061]

[0062] Calculate the uplink confidentiality transmission rate that can be achieved in uplink transmission

[0063]

[0064] The transmission rate of the upstream transmission that is not attacked by the attacker Eve

[0065]

[0066] Furthermore, the data transmission process of downlink transmission is:

[0067] Calculate the kth user terminal U k After offloading the task, access point A c The post-processed data is transmitted to the kth user terminal U using beamforming technology. k , the kth user terminal U k The received signal y k It is expressed as:

[0068]

[0069] Among them, ω ck For post-processing data from access point A c To user terminal U k The precoding vector is Access point A c With user terminal U k The channel state information between ck Access point A c To user terminal U k The arrival angle of g(.) is the arrival angle θ ck The gain function, η ck Access point A c With user terminal U k The association, Access point A c and user terminal U k The conjugate transpose of the channel state information between ck From access point A c To user terminal U k Post-processing data, n k For user terminal U k The additive Gaussian white noise of c is access point A c The number of Ε{|x ck | 2 =P c , Ε{.} is the expected function, P c Access point A c The transmission power;

[0070] The kth user terminal U in downlink transmission k The signal-to-noise ratio γk for:

[0071]

[0072] Among them, σ k is the kth user terminal U k The standard deviation of the additive white Gaussian noise at ;

[0073] The signal received by the attacker Eve during downlink transmission for:

[0074]

[0075] Among them, θ ce Access point A c To the arrival angle of the attacker Eve, Access point A c and the conjugate transpose of the channel between attacker Eve, ω ce For post-processing data from access point A c To the attacker Eve’s pre-coded vector, x ce From access point A c To the attacker Eve's post-processing data, Access point A c Channel state information to attacker Eve;

[0076] The signal-to-noise ratio of the attacker Eve in the downlink transmission for:

[0077]

[0078] Calculate the achievable downlink confidentiality transmission rate in downlink transmission

[0079]

[0080] The transmission rate of the downlink transmission that is not attacked by the attacker Eve

[0081]

[0082] Furthermore, the task offloading model in the task offloading decision is:

[0083] Suppose that the kth user terminal U k The total task calculated at is T k , and the task T k Divided into two parts, including one part for the ontology calculation task λ k T k , and the other part offloads the tasks on the edge server ES (1-λk )T k ; k is the uninstall rate of the user terminal, λ k ∈[0,1].

[0084] The beneficial effects of the present invention are:

[0085] The present invention proposes a new computation offloading scheme for non-cellular massive MIMO scenarios to effectively counter the capable attacker Eve to ensure uplink offloading task transmission and downlink post-transmission data transmission. Specifically: (1) During the uplink offloading task transmission process, the full-duplex access point AP-ES intentionally sends an artificial noise signal to the attacker Eve. (2) During the downlink data post-transmission process, based on the arrival angle information difference between the user terminal UE and the attacker Eve, in order to counter Eve's PCA; a new secure computation task offloading model is proposed to ensure uplink and downlink transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 System diagram for a joint security and energy load balancing network system. DETAILED DESCRIPTION

[0087] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0088] like Figure 1 As shown, a network system combining security and energy load balancing includes:

[0089] Access point AP: equipped with N t antennas, the access point AP includes L access points, the access point AP is connected to the CPU through a wired backhaul link, all access points AP serve K single-antenna user terminals UE, all access points AP are equipped with independent edge servers ES, and form access point AP-ES equipped with independent edge servers;

[0090] Single-antenna attacker Eve: used to intercept legitimate information;

[0091] All access points AP-ES, user terminals UE and attacker Eve are randomly distributed in the coverage area, and L>>K. The set of access points AP-ES is A={1,2,…,l,…,L}, where l is the number of the access point AP-ES, and the set of user terminals UE is U={1,2,…,k,…,K}, where k is the number of the user terminal UE.

[0092] The access point AP-ES and the attacker Eve work in full-duplex mode. The attacker Eve intercepts uplink transmission through passive eavesdropping and intercepts downlink transmission through active pilot pollution attack. The access point AP-ES sends artificial noise signals to the attacker Eve during the uplink task offloading transmission to resist passive eavesdropping.

[0093] The method by which the access point AP-ES, the attacker Eve, and the user terminal UE perform data transmission within the coverage area is as follows:

[0094] S1: Each user terminal UE first sends the assigned pilot sequence to the access point AP-ES;

[0095] S2: The access point AP-ES determines whether the user terminal UE is under attack by detecting abnormal pilot signals;

[0096] S3: If the user terminal UE is not attacked by the attacker Eve, it is marked as a normal user terminal UE, otherwise, it is marked as an attacked user terminal UE;

[0097] For the attacked user terminal UE, the access point AP-ES determines whether the arrival angle AOA interval between the user terminal UE and the attacker Eve meets the security transmission condition; if so, the access point AP-ES maintains the connection with the user terminal UE, otherwise, the access point AP-ES disconnects the connection with the user terminal UE;

[0098] S4: The user terminal UE loads system information from the access point AP-ES, and then calculates the achievable confidential transmission rate of uplink transmission and downlink transmission. The user terminal UE makes a task offloading decision based on the access point AP-ES and its current matching status;

[0099] S5: Each access point AP-ES reports its current load to the CPU according to the amount of calculation offloaded from the optimal task offloading decision made by the user terminal UE;

[0100] S6: The CPU calculates the energy-based load imbalance and feeds it back to each access point AP-ES; based on the current load imbalance, each access point AP-ES decides whether to provide services to the user terminal UE, forming the optimal access point AP-ES service selection strategy H - ;

[0101] S7: The user terminal UE estimates the channel state information of the uplink transmission and transmits the offload data in the task offloading decision through the uplink confidentiality transmission rate sent to the corresponding access point AP-ES; at the same time, the access point AP-ES uses the optimal interference strategy J * Send jamming signals to the attacker Eve;

[0102] S8: Afterwards, the access point AP-ES transmits the post-processed data to the user terminal UE through beamforming technology. The post-processed data is the data that the edge server ES calculates the task uploaded by the user terminal UE and returns to the user terminal UE after the calculation is completed.

[0103] The whole transmission offloading process can be divided into three processes, namely uplink channel estimation, uplink task offloading and downlink post-processing data transmission.

[0104] For subsequent analysis and calculation, the present invention considers a sector-based antenna pattern model for characterizing the gain of a directional antenna. The gain of a single antenna of the access point AP-ES during data transmission is:

[0105]

[0106] Among them, θ li is the arrival angle from the lth access point AP-ES to the attacker Eve or the user terminal UE, is the beam width of the beam formed at the access point AP-ES, g s is the sidelobe gain, 0 <g s <1,g m is the main lobe gain, i∈{k,e}, e is the number of the attacker Eve, i is the number of the attacker Eve or the user terminal UE, α(θ li ) is the steering vector from the lth access point AP-ES to the user terminal UE or the attacker Eve;

[0107]

[0108] Where, d is the antenna distance between access points AP-ES, and λ is the signal wavelength.

[0109] Since the communication mode between the access point AP-ES and the user terminal UE adopted by the present invention is TDD (time division duplex) mode, the transmission includes a training phase for uplink channel estimation and a downlink data transmission phase. The present invention assumes that the channel condition is static or changes slowly over the coherence interval T. Therefore, the access point AP-ES can obtain fine large-scale fading coefficients.

[0110] The channel model between the lth access point AP-ES and the kth user terminal UE is:

[0111]

[0112] Among them, h lk is the channel between the access point AP-ES and the user terminal UE, is the linear space of the channel in the complex field, β lk is the large-scale fading coefficient of the channel between the access point AP-ES and the user terminal UE, is the small-scale fading coefficient of the channel between the access point AP-ES and the user terminal UE, α(θ lk ) is the steering vector from the lth access point AP-ES to the kth user terminal UE, θ lk is the arrival angle from the lth access point AP-ES to the kth user terminal UE;

[0113] The channel model between the lth access point AP-ES and the attacker Eve is:

[0114]

[0115] Among them, h le is the channel between the lth access point AP-ES and the eth attacker Eve, β le is the large-scale fading coefficient of the channel between the lth access point AP-ES and the eth access point Eve, is the small-scale fading coefficient of the channel between the lth access point AP-ES and the eth access point Eve, α(θ le ) is the steering vector from the lth access point AP-ES to the eth attacker Eve, θ le is the arrival angle from the lth access point AP-ES to the eth user terminal UE;

[0116] The channel model between the jth user terminal UE and the eth attacker Eve is:

[0117]

[0118] Among them, h je is the channel between the user terminal UE and the attacker Eve, β je is the large-scale fading coefficient of the channel between the j-th user terminal UE and the e-th attacker Eve, is the small-scale fading coefficient of the channel between the j-th user terminal UE and the e-th attacker Eve.

[0119] The link training process for uplink transmission is:

[0120] The user terminal UE sends the assigned pilot sequence to the access point AP-ES through the uplink channel. The access point AP-ES obtains the estimated downlink channel state information through channel reciprocity in the time division duplex mode for data precoding and data transmission;

[0121] The pilot sequence information received by the access point AP-ES is:

[0122]

[0123] Among them, Y Al is the pilot sequence information received by the lth access point AP-ES, U p ={1,2,…,P},U p is the user terminal UE subset that is attacked by the attacker Eve during the link training process of uplink transmission, j is the number of the user terminal UE in the user terminal UE subset, n l is the additive Gaussian white noise at the position of the lth access point AP-ES, and n l ~CN(0,I), I is the unit matrix, ~CN(0,I) represents the additive Gaussian white noise n l The complex random variable formed obeys a zero-mean cyclic symmetric complex Gaussian distribution, τ is the length of the normalized mutually orthogonal pilot sequence, P p is the average power of the user terminal UE transmitting the pilot sequence to the access point AP-ES, P e Intercept pilot sequence for Eve The average power sent to the access point AP-ES, is a normalized mutually orthogonal pilot sequence sent by the k-th user terminal UE to the access point AP-ES, is the pilot sequence of the jth user terminal UE intercepted by the attacker Eve, The legal pilot sequence information received by the access point AP-ES. It is the active pilot pollution attack information of the attacker Eve.

[0124] After receiving the pilot sequence information of the user terminal UE, the access point AP-ES detects the abnormal pilot sequence information that may be attacked by the attacker Eve, and sends the abnormal pilot sequence information Y Al Project to The estimated channel state information is obtained by using the least square method;

[0125]

[0126] in, is the estimated channel state information, Pilot sequence The conjugate transpose of .

[0127] Since previous studies have shown that pilot pollution attacks (PCA) can be detected on access point AP-ES and the attacked user terminal UE can be identified, we believe that access point AP-ES can separate the kth client UE from the attacker Eve through the difference in angle of arrival (AOA) information. Therefore, access point AP-ES can obtain pure channel estimation information based on the beam domain channel estimation method without affecting the active eavesdropper.

[0128] The task offloading process for uplink transmission is as follows:

[0129] After the link training process of uplink transmission is completed, an access point subset is established in which the kth user terminal UE is connected to multiple access points AP-ES L′≤L, a subset of user terminals UE associated with the access point AP-ES K′≤K, for task offloading;

[0130] When the user terminal UE offloads the task to the corresponding access point AP-ES, the access point AP-ES simultaneously emits an artificial noise signal to resist the passive eavesdropping of the attacker Eve; the matching matrix H = L × K is used to represent the association between any user terminal and any access point, and the elements in the matching matrix H are expressed as;

[0131]

[0132] Among them, η lk For user terminal U k With access point A l Associated elements, user terminal U k With access point A l When associated, η lk =1, otherwise, η lk =0;

[0133] Subset Access point A in c From the subset User terminal U in k Received signal for:

[0134]

[0135] Among them, x k For user terminal U k The transmitted signal, Ε{x k 2}=1,n c Access point A c The additive Gaussian white noise of For user terminal U kThe transmission power, v is the artificial noise vector, z is the additive Gaussian white noise signal, and is the power of artificial noise emitted by the lth access point AP-ES, v H is the conjugate transpose of vector v, μ c is the residual self-interference coefficient, indicating the self-interference performance, H is the self-interference channel matrix, η ck For user terminal U k With access point A c The associated element, h ck For user terminal U k With access point A c The channel between

[0136] Access point A for uplink transmission c Signal-to-noise ratio for:

[0137]

[0138] Among them, σ c Access point A c The standard deviation of the additive Gaussian white noise at H is the conjugate transpose of the self-interference channel matrix;

[0139] The attacker Eve receives the data from the user terminal U k The signal for:

[0140]

[0141] Among them, h ke For user terminal U k The channel between the attacker Eve, m le Access point A l The associated element with the attacker Eve, n e is the additive Gaussian white noise of the attacker Eve, k∈[1,P],σ e is the standard deviation of the additive Gaussian white noise at the attacker Eve;

[0142] The interference strategy of access point AP-ES is defined as a matching matrix J = L × 1, which represents the association between access point AP-ES and attacker Eve. The element m of the matching matrix J is le for:

[0143]

[0144] If access point A l Send an artificial noise signal to the attacker Eve, then m le =1, otherwise, mle =0;

[0145] The signal-to-noise ratio of the attacker Eve in the uplink transmission for:

[0146]

[0147] Calculate the uplink confidentiality transmission rate that can be achieved in uplink transmission

[0148]

[0149] The transmission rate of the upstream transmission that is not attacked by the attacker Eve

[0150]

[0151] The data transmission process of downlink transmission is as follows:

[0152] Calculate the kth user terminal U k After offloading the task, access point A c The post-processed data is transmitted to the kth user terminal U using beamforming technology. k , the kth user terminal U k The received signal y k It is expressed as:

[0153]

[0154] Among them, ω ck For post-processing data from access point A c To user terminal U k The precoding vector is Access point A c With user terminal U k The channel state information between ck Access point A c To user terminal U k The arrival angle of g(.) is the arrival angle θ ck The gain function, η ck Access point A c With user terminal U k The association, Access point A c and user terminal U k The conjugate transpose of the channel state information between ck From access point A c To user terminal U k Post-processing data, n k For user terminal U k The additive Gaussian white noise of c is access point A c The number of Ε{|x ck | 2 =P c , Ε{.} is the expected function, P c Access point A c The transmission power;

[0155] The kth user terminal U in downlink transmission k The signal-to-noise ratio γ k for:

[0156]

[0157] Among them, σ k is the kth user terminal U k The standard deviation of the additive white Gaussian noise at ;

[0158] The signal received by the attacker Eve during downlink transmission for:

[0159]

[0160] Among them, θ ce Access point A c To the arrival angle of the attacker Eve, Access point A c and the conjugate transpose of the channel between attacker Eve, ω ce For post-processing data from access point A c To the attacker Eve’s pre-coded vector, x ce From access point A c To the attacker Eve's post-processing data, Access point A c Channel state information to attacker Eve;

[0161] The signal-to-noise ratio of the attacker Eve in the downlink transmission for:

[0162]

[0163] Calculate the achievable downlink confidentiality transmission rate in downlink transmission

[0164]

[0165] The transmission rate of the downlink transmission that is not attacked by the attacker Eve

[0166]

[0167] The task offloading model in task offloading decision is:

[0168] Suppose that the kth user terminal U k The total task calculated at is T k , and the task T k Divided into two parts, including one part for the ontology calculation task λ k T k , and the other part offloads the tasks on the edge server ES (1-λ k )T k ; k is the uninstall rate of the user terminal, λ k ∈[0,1].

[0169] The present invention proposes a new computation offloading scheme for non-cellular massive MIMO scenarios to effectively counter the capable attacker Eve to ensure uplink offloading task transmission and downlink post-transmission data transmission. Specifically: (1) During the uplink offloading task transmission process, the full-duplex access point AP-ES intentionally sends an artificial noise signal to the attacker Eve. (2) During the downlink data post-transmission process, based on the arrival angle information difference between the user terminal UE and the attacker Eve, in order to counter Eve's PCA; a new secure computation task offloading model is proposed to ensure uplink and downlink transmission.

Claims

1. A network system combining security and energy load balancing, characterized in that: include: Access point AP: equipped with N t antennas, the access point AP includes L access points, the access point AP is connected to the CPU through a wired backhaul link, all access points AP serve K single-antenna user terminals UE, all access points AP are equipped with independent edge servers ES, and form access point AP-ES equipped with independent edge servers; Single-antenna attacker Eve: used to intercept legitimate information; All access points AP-ES, user terminals UE and attacker Eve are randomly distributed in the coverage area, and L>>K. The set of access points AP-ES is A={1,2,…,l,…,L}, where l is the number of the access point AP-ES, and the set of user terminals UE is U={1,2,…,k,…,K}, where k is the number of the user terminal UE. The access point AP-ES and the attacker Eve work in full-duplex mode. The attacker Eve intercepts the uplink transmission through passive eavesdropping and intercepts the downlink transmission through active pilot pollution attack. The access point AP-ES sends artificial noise signals to the attacker Eve during the uplink task offloading transmission process to resist passive eavesdropping. The method for the access point AP-ES, the attacker Eve, and the user terminal UE to perform data transmission in the coverage area is: S1: Each user terminal UE first sends the assigned pilot sequence to the access point AP-ES; S2: The access point AP-ES determines whether the user terminal UE is under attack by detecting abnormal pilot signals; S3: If the user terminal UE is not attacked by the attacker Eve, it is marked as a normal user terminal UE, otherwise, it is marked as an attacked user terminal UE; For the attacked user terminal UE, the access point AP-ES determines whether the arrival angle AOA interval between the user terminal UE and the attacker Eve meets the security transmission condition; if so, the access point AP-ES maintains the connection with the user terminal UE, otherwise, the access point AP-ES disconnects the connection with the user terminal UE; S4: The user terminal UE loads system information from the access point AP-ES, and then calculates the achievable confidential transmission rate of uplink transmission and downlink transmission. The user terminal UE makes a task offloading decision based on the access point AP-ES and its current matching status; S5: Each access point AP-ES reports its current load to the CPU according to the amount of calculation offloaded from the optimal task offloading decision made by the user terminal UE; S6: The CPU calculates the energy-based load imbalance and feeds it back to each access point AP-ES; based on the current load imbalance, each access point AP-ES decides whether to provide services to the user terminal UE, forming the optimal access point AP-ES service selection strategy H * ; S7: The user terminal UE estimates the channel state information of the uplink transmission and transmits the offload data in the task offloading decision through the uplink confidentiality transmission rate sent to the corresponding access point AP-ES; at the same time, the access point AP-ES uses the optimal interference strategy J * Send jamming signals to the attacker Eve; S8: Afterwards, the access point AP-ES transmits the post-processed data to the user terminal UE through beamforming technology; The gain of the single antenna of the access point AP-ES during data transmission is: Among them, θ li is the arrival angle from the lth access point AP-ES to the attacker Eve or the user terminal UE, is the beam width of the beam formed at the access point AP-ES, g s is the sidelobe gain, 0 <g s <1,g m is the main lobe gain, i∈{k,e}, e is the number of the attacker Eve, i is the number of the attacker Eve or the user terminal UE, α(θ li ) is the steering vector from the lth access point AP-ES to the user terminal UE or the attacker Eve; Where d is the antenna distance between access points AP-ES, and λ is the signal wavelength; The channel model between the lth access point AP-ES and the kth user terminal UE is: Among them, h lk is the channel between the access point AP-ES and the user terminal UE, is the linear space of the channel in the complex field, β lk is the large-scale fading coefficient of the channel between the access point AP-ES and the user terminal UE, is the small-scale fading coefficient of the channel between the access point AP-ES and the user terminal UE, α(θ lk ) is the steering vector from the lth access point AP-ES to the kth user terminal UE, θ lk is the arrival angle from the lth access point AP-ES to the kth user terminal UE; The channel model between the first access point AP-ES and the attacker Eve is: Among them, h le is the channel between the lth access point AP-ES and the eth attacker Eve, β le is the large-scale fading coefficient of the channel between the lth access point AP-ES and the eth attacker Eve, is the small-scale fading coefficient of the channel between the lth access point AP-ES and the eth attacker Eve, α(θ le ) is the steering vector from the lth access point AP-ES to the eth attacker Eve, θ le is the arrival angle from the lth access point AP-ES to the eth user terminal UE; The channel model between the jth user terminal UE and the eth attacker Eve is: Among them, h je is the channel between the user terminal UE and the attacker Eve, β je is the large-scale fading coefficient of the channel between the j-th user terminal UE and the e-th attacker Eve, is the small-scale fading coefficient of the channel between the j-th user terminal UE and the e-th attacker Eve; The link training process of the uplink transmission is as follows: The user terminal UE sends the assigned pilot sequence to the access point AP-ES through the uplink channel. The access point AP-ES obtains the estimated downlink channel state information through channel reciprocity in the time division duplex mode for data precoding and data transmission; The pilot sequence information received by the access point AP-ES is: Among them, Y Al is the pilot sequence information received by the lth access point AP-ES, U p ={1,2,…,P},U p is the user terminal UE subset that is attacked by the attacker Eve during the link training process of uplink transmission, j is the number of the user terminal UE in the user terminal UE subset, n l is the additive Gaussian white noise at the position of the lth access point AP-ES, and n l ~CN(0,I), I is the unit matrix, ~CN(0,I) represents the additive Gaussian white noise n l The complex random variable formed obeys a zero-mean cyclic symmetric complex Gaussian distribution, τ is the length of the normalized mutually orthogonal pilot sequence, P p is the average power of the user terminal UE transmitting the pilot sequence to the access point AP-ES, P e Intercept pilot sequence for Eve The average power sent to the access point AP-ES, is a normalized mutually orthogonal pilot sequence sent by the k-th user terminal UE to the access point AP-ES, is the pilot sequence of the jth user terminal UE intercepted by the attacker Eve, The legal pilot sequence information received by the access point AP-ES. It is the active pilot pollution attack information of the attacker Eve; After receiving the pilot sequence information of the user terminal UE, the access point AP-ES detects abnormal pilot sequence information that may be attacked by the attacker Eve, and sends the abnormal pilot sequence information Y Al Project to The estimated channel state information is obtained by using the least square method; in, is the estimated channel state information, is the pilot sequence The conjugate transpose of ; The task offloading process of the uplink transmission is as follows: After the link training process of uplink transmission is completed, an access point subset is established in which the kth user terminal UE is connected to multiple access points AP-ES L′≤L, a subset of user terminals UE associated with the access point AP-ES K′≤K, for task offloading; When the user terminal UE offloads the task to the corresponding access point AP-ES, the access point AP-ES simultaneously emits an artificial noise signal to resist the passive eavesdropping of the attacker Eve; the matching matrix H = L × K is used to represent the association between any user terminal and any access point, and the elements in the matching matrix H are expressed as; Among them, η lk For user terminal U k With access point A l Associated elements, user terminal U k With access point A l When associated, η lk =1, otherwise, η lk =0; Subset Access point A in c From the subset User terminal U in k Received signal for: Among them, x k For user terminal U k The transmitted signal, Ε{x k 2 }=1,n c Access point A c The additive Gaussian white noise of P t k For user terminal U k The transmission power, v is the artificial noise vector, z is the additive Gaussian white noise signal, and is the power of artificial noise emitted by the lth access point AP-ES, v H is the conjugate transpose of vector v, μ c is the residual self-interference coefficient, indicating the self-interference performance, H is the self-interference channel matrix, η ck For user terminal U k With access point A c The associated element, h ck For user terminal U k With access point A c The channel between Access point A for uplink transmission c Signal-to-noise ratio for: Among them, σ c Access point A c The standard deviation of the additive Gaussian white noise at H is the conjugate transpose of the self-interference channel matrix; The attacker Eve in the uplink transmission receives the k The signal for: Among them, h ke For user terminal U k The channel between the attacker Eve, m le Access point A l The associated element with the attacker Eve, n e is the additive Gaussian white noise of the attacker Eve, k∈[1,P],σ e is the standard deviation of the additive Gaussian white noise at the attacker Eve; The interference strategy of access point AP-ES is defined as a matching matrix J = L × 1, which represents the association between access point AP-ES and attacker Eve. The element m of the matching matrix J is le for: If access point A l Send an artificial noise signal to the attacker Eve, then m le =1, otherwise, m le =0; The signal-to-noise ratio of the attacker Eve in the uplink transmission for: Calculate the uplink confidentiality transmission rate that can be achieved in uplink transmission The transmission rate of the upstream transmission that is not attacked by the attacker Eve 2. The network system for joint security and energy load balancing according to claim 1, characterized in that: The data transmission process of the downlink transmission is as follows: Calculate the kth user terminal U k After offloading the task, access point A c The post-processed data is transmitted to the kth user terminal U using beamforming technology. k , the kth user terminal U k The received signal y k It is expressed as: Among them, ω ck For post-processing data from access point A c To user terminal U k The precoding vector is Access point A c With user terminal U k The channel state information between ck Access point A c To user terminal U k The arrival angle of g(.) is the arrival angle θ ck The gain function, η ck Access point A c With user terminal U k The association, Access point A c and user terminal U k The conjugate transpose of the channel state information between ck From access point A c To user terminal U k Post-processing data, n k For user terminal U k The additive Gaussian white noise of c is access point A c The number of Ε{|x ck | 2 =P c , Ε{.} is the expected function, P c Access point A c The transmission power; The kth user terminal U in downlink transmission k The signal-to-noise ratio γ k for: Among them, σ k is the kth user terminal U k The standard deviation of the additive white Gaussian noise at ; The signal received by the attacker Eve during downlink transmission for: Among them, θ ce Access point A c To the arrival angle of the attacker Eve, Access point A c and the conjugate transpose of the channel between attacker Eve, ω ce For post-processing data from access point A c To the attacker Eve’s pre-coded vector, x ce From access point A c To the attacker Eve's post-processing data, Access point A c Channel state information to attacker Eve; The signal-to-noise ratio of the attacker Eve in the downlink transmission for: Calculate the achievable downlink confidentiality transmission rate in downlink transmission The transmission rate of the downlink transmission that is not attacked by the attacker Eve 3. The network system for joint security and energy load balancing according to claim 1, characterized in that: The task offloading model in the task offloading decision is: Suppose that the kth user terminal U k The total task calculated at is T k , and the task T k Divided into two parts, including one part for the ontology calculation task λ k T k , and the other part offloads the tasks on the edge server ES (1-λ k )T k ; k is the uninstall rate of the user terminal, λ k ∈[0,1].

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