CN107438249B - Safety detection method and device for distributed safety communication system - Google Patents

Abstract

The present invention provides a security detection method for a distributed security communication system. The method includes: monitoring a first signal sent by a plurality of transmitting end devices to a receiving end device in the nth time slot, where the first signal includes a first artificial noise signal , where the nth time slot is the current time slot, and n is a positive integer; according to the first signal, determine the first signal-to-interference-to-noise ratio SINR of the eavesdropping end device; 1. Eavesdropping capacity; According to the first eavesdropping capacity and the obtained receiving capacity of the receiving end device, determine the security capacity of the receiving end device; Adjust the receiving beam weight of the beamformer of the eavesdropping end device according to the third angle of arrival from the transmitting end device to the receiving end device. The embodiments of the present invention can detect the security of the distributed security communication system.

Description

Safety detection method and device for distributed safety communication system

technical field

The present invention relates to the field of communication technologies, and in particular, to a security detection method and device of a distributed security communication system.

Background technique

Distributed beamforming is a collaborative communication technology. Multiple transmitter devices send the same information to the target device, and by controlling the transmission phase of the transmitter device, the signals of multiple transmitter devices are sent to the target device. Devices are effectively merged.

The current communication environment is generally complicated. When there is an eavesdropping device in the environment, the eavesdropping device can estimate the channel direction information according to the signal sent by the transmitting device to the receiving device, and adjust its beamformer accordingly to make its own Therefore, the security of the distributed secure communication system will decrease. How to detect the security of the distributed secure communication system is a technical issue that needs to be solved urgently.

SUMMARY OF THE INVENTION

The embodiment of the present invention discloses a security detection method and device of a distributed security communication system, which can detect the security of the distributed security communication system.

A first aspect of the embodiments of the present invention discloses a security detection method for a distributed security communication system, which is applied to an eavesdropping terminal device included in a distributed security communication system. The distributed security beamforming system further includes a plurality of transmitting terminal devices and The receiving end device, the method includes:

Monitoring multiple first signals sent by the transmitting end device to the receiving end device in the nth time slot, the first signals include a first artificial noise signal, wherein the nth time slot is the current time slot, so Said n is a positive integer;

According to the first signal, determine the first signal-to-interference and noise ratio SINR of the eavesdropping terminal device;

According to the first SINR, determine the first eavesdropping capacity of the nth time slot of the eavesdropping terminal device;

According to the first eavesdropping capacity and the acquired receiving capacity of the receiving end device, determine the security capacity of the receiving end device;

According to the changing trend of the security capacity, the security of the distributed security communication system is detected.

As an optional implementation manner, in the first aspect of the embodiment of the present invention, the method further includes:

According to the first signal, determine the first angle of arrival of each of the transmitting end equipment to the eavesdropping end device, to estimate the direction angle from the transmitting end device to the receiving end device;

A first beamformer is established for the first signal.

As an optional implementation manner, in the first aspect of the embodiment of the present invention, the method further includes:

monitoring the feedback signals sent by the receiving end device to a plurality of the transmitting end devices in the nth time slot, and establishing a second beamformer for the feedback signals;

According to the feedback signal, the second SINR of the eavesdropping terminal device is determined.

As an optional implementation manner, in the first aspect of the embodiment of the present invention, the method further includes:

According to the feedback signal, determine the second angle of arrival from the receiving end device to the eavesdropping end device;

Determine the third angle of arrival from the transmitting end device to the receiving end device according to the first angle of arrival and the second angle of arrival;

According to the third angle of arrival, the receiving beam weight of the first beamformer of the eavesdropping end device is adjusted.

的正态分布，其中，

SINR_E1为所述第一SINR，SINR_E2为所述第二SINR，k为常数。As an optional implementation manner, in the first aspect of the embodiment of the present invention, the first eavesdropping capacity depends on the eavesdropping end device sending the first artificial noise signal to the nth time slot of the transmitting end device The estimated error of the zero-sag angle, the estimated error obeys the mean value of 0, and the variance is

the normal distribution of , where,

SINR _E1 is the first SINR, SINR _E2 is the second SINR, and k is a constant.

As an optional implementation manner, in the first aspect of the embodiment of the present invention, multiple antennas are installed on the eavesdropping terminal device, and the multiple antennas are used to receive the first signal or the feedback signal.

A second aspect of the embodiments of the present invention discloses a security detection device, which operates on an eavesdropping terminal device included in a distributed security communication system, and includes:

a monitoring unit, configured to monitor a plurality of first signals sent by the transmitting end device to the receiving end device in the nth time slot, where the first signals include a first artificial noise signal, wherein the nth time slot is the current time slot, the n is a positive integer;

a determining unit, configured to determine the first signal-to-interference-to-noise ratio SINR of the eavesdropping terminal device according to the first signal;

The determining unit is further configured to determine the first eavesdropping capacity of the nth time slot of the eavesdropping terminal device according to the first SINR;

The determining unit is further configured to determine the security capacity of the receiving end device according to the first eavesdropping capacity and the obtained receiving capacity of the receiving end device;

A detection unit, configured to detect the security of the distributed security communication system according to the change trend of the security capacity.

As an optional implementation manner, in the second aspect of the embodiment of the present invention, the determining unit is further configured to determine, according to the first signal, the first connection between each transmitting end device and the eavesdropping end device. Arrival angle, to estimate the direction angle from the transmitting end device to the receiving end device;

The safety detection device also includes:

A establishing unit, configured to establish a first beamformer for the first signal.

As an optional implementation manner, in the second aspect of the embodiment of the present invention, the monitoring unit is further configured to monitor feedback signals sent by the receiving end device to a plurality of the transmitting end devices in the nth time slot;

The establishing unit is further configured to establish a second beamformer for the feedback signal;

The determining unit is further configured to determine the second SINR of the eavesdropping terminal device according to the feedback signal.

As an optional implementation manner, in the second aspect of the embodiment of the present invention, the determining unit is further configured to determine a second angle of arrival from the receiving end device to the eavesdropping end device according to the feedback signal ;

The determining unit is further configured to determine a third angle of arrival from the transmitting end device to the receiving end device according to the first angle of arrival and the second angle of arrival;

The safety detection device also includes:

An adjustment unit, configured to adjust the receiving beam weight of the first beamformer of the eavesdropping terminal device according to the third angle of arrival.

的正态分布，其中，

SINR_E1为所述第一SINR，SINR_E2为所述第二SINR，k为常数。As an optional implementation manner, in the second aspect of the embodiment of the present invention, the first eavesdropping capacity depends on the eavesdropping end device sending the first artificial noise signal to the nth time slot of the transmitting end device The estimated error of the zero-sag angle, the estimated error obeys the mean value of 0, and the variance is

the normal distribution of , where,

SINR _E1 is the first SINR, SINR _E2 is the second SINR, and k is a constant.

As an optional implementation manner, in the second aspect of the embodiment of the present invention, multiple antennas are installed on the eavesdropping terminal device, and the multiple antennas are used to receive the first signal or the feedback signal.

Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

In this embodiment of the present invention, the eavesdropping end device may monitor multiple first signals sent by the transmitting end device to the receiving end device in the nth time slot, where the first signals include a first artificial noise signal, wherein the The nth time slot is the current time slot, and the n is a positive integer; further, the eavesdropping end device may determine the first signal-to-interference and noise ratio SINR of the eavesdropping end device according to the first signal; an SINR, to determine the first eavesdropping capacity of the nth time slot of the eavesdropping end device; further, the eavesdropping end device may determine the receiving end device according to the first eavesdropping capacity and the acquired receiving capacity of the receiving end device The security capacity of the terminal device is detected, and the security of the distributed secure communication system is detected according to the changing trend of the security capacity. It can be seen that, by implementing the embodiments of the present invention, the security of the distributed secure communication system can be detected by listening to the change trend of the security capacity of the receiving end device determined by the eavesdropping end device.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic diagram of a model of a distributed secure communication system disclosed in an embodiment of the present invention;

2 is a schematic flowchart of a security detection method for a distributed security communication system disclosed in an embodiment of the present invention;

3 is a schematic flowchart of another security detection method of a distributed security communication system disclosed in an embodiment of the present invention;

4 is a schematic diagram of convergence of an artificial noise signal under different estimation errors disclosed in an embodiment of the present invention;

5 is a schematic diagram of the convergence of the security capacity of a distributed security communication system disclosed in an embodiment of the present invention;

6 is a schematic diagram of the convergence of the security capacity of another distributed security communication system disclosed in an embodiment of the present invention;

7 is a schematic structural diagram of a security detection device disclosed in an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of another security detection apparatus disclosed in an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "first" and "second" in the description and claims of the present invention and the above drawings are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes For other steps or units inherent to these processes, methods, products or devices.

The embodiment of the present invention discloses a security detection method and device of a distributed security communication system, which can detect the security of the distributed security communication system. A detailed description will be given below with reference to the accompanying drawings.

Please refer to FIG. 1. FIG. 1 is a schematic diagram of a model of a distributed secure communication system disclosed in an embodiment of the present invention. As shown in FIG. 1 , the distributed secure communication system includes a plurality of transmitting end devices S _i (i=1, 2, 3....N, and N is a positive integer), a receiving end device D and an eavesdropping end device E . Wherein, each transmitting end device S _i and receiving end device D are equipped with a single antenna, and the eavesdropping end device E is equipped with multiple antennas.

The transmitter device _Si is mainly used to send and receive signals, such as sending artificial noise signals and receiving feedback signals, and the transmitter device _Si may be a base station. A base station (eg, an access point) may refer to a device in an access network that communicates with wireless terminals over the air interface through one or more sectors. The base station may be used to convert received air frames to and from IP packets, acting as a router between the wireless terminal and the rest of the access network, which may include an Internet Protocol (IP) network. The base station may also coordinate attribute management of the air interface. For example, the base station may be a base station (BTS, Base Transceiver Station) in GSM or CDMA, a base station (NodeB) in WCDMA, or an evolved base station (NodeB or eNB or e-NodeB, evolutional Node) in LTE B), the embodiments of the present invention are not limited.

The receiving end device D is mainly used to send and receive signals, such as sending artificial noise signals and receiving useful signals, and the target end device D may be a base station.

Among them, the eavesdropping device E is mainly used to monitor the signal sent by the transmitting end device _Si to the receiving end device D, and the signal sent by the receiving end device D to the transmitting end device Si, and adjust its own _beamforming according to the received signal. The eavesdropping device E may include, but is not limited to, a base station, a user equipment, a communication vehicle, and the like.

因此，第i个发射端设备到接收端设备D的自由空间路径损耗为

式中λ表示载波波长，

表示第i个发射端设备到接收端设备D的距离。h_SiD表示第i个发射端设备到接收端设备D的信道衰落。

表示第i个发射端设备到窃听端设备E的自由空间路径损耗，式中

表示第i个发射端设备到窃听端设备E的距离，h_SiE表示第i个发射端设备到窃听端设备E的信道衰落。L_DE＝λ/4πd_DE表示接收端设备D与窃听端设备E之间的自由空间路径损耗，

则表示接收端设备D与窃听端设备E之间的距离。h_DE则表示接收端设备D与窃听端设备E之间的信道衰落。类似于以上的定义方法，

分别表示接收端设备D在发送反馈信号时与第i个发射端设备间的自由空间路径损耗、距离以及信道衰落。In the distributed secure communication system shown in Figure 1, the coordinates of the receiving end device D are expressed as (0,r _D ), and the coordinates of the eavesdropping end device E are expressed as (r _E sinθ _E , r _E cosθ _E ), where θ _E represents the angle between the eavesdropping end device E and the y-axis under the coordinates shown in FIG. 1 . N distributed transmitter devices that have undergone frequency synchronization are randomly distributed in a circle with a radius of r _S , and the distribution law of these transmitter devices conforms to a uniform distribution, that is, each distributed transmitter device appears at any position in the circle the same probability. Among them, the coordinates of the i-th transmitter device S _i (i=1,2,...,N) can be expressed as

Therefore, the free space path loss from the i-th transmitter device to the receiver device D is

where λ represents the carrier wavelength,

Indicates the distance from the i-th transmitter device to the receiver device D. h _SiD represents the channel fading from the i-th transmitter device to the receiver device D.

represents the free space path loss from the i-th transmitter device to the eavesdropping device E, where

represents the distance from the i-th transmitter device to the eavesdropping device E, and h _SiE represents the channel fading from the i-th transmitter device to the eavesdropping device E. L _DE =λ/4πd _DE represents the free space path loss between the receiving end device D and the eavesdropping end device E,

Then it represents the distance between the receiving end device D and the eavesdropping end device E. h _DE represents the channel fading between the receiving end device D and the eavesdropping end device E. Similar to the above definition method,

respectively represent the free space path loss, distance and channel fading between the receiving end device D and the i-th transmitting end device when sending the feedback signal.

Among them, any distributed transmitting end device S _i (i=1,2,...,N) and receiving end device D are equipped with omnidirectional single antenna, and the eavesdropping end device E is equipped with a multi-antenna array to obtain more More channel direction information is obtained, thereby improving the eavesdropping capacity of the eavesdropping end device E. For example, by estimating the direction of arrival (Direction of Arrival) between the distributed transmitting end device and the receiving end device D to design its own beamformer.

In the distributed safety communication system shown in FIG. 1 , each transmitting end device may send a first signal carrying a first artificial noise signal to the receiving end device in the nth time slot, the first artificial noise signal It is used to interfere with the estimation accuracy of the first channel direction information by the eavesdropping end device; at the same time, the eavesdropping end device will also monitor the first signal sent by each transmitting end device to the receiving end device, and according to the received The signal establishes a first beamformer; after the receiving end device receives the first signal carrying the first artificial noise signal sent by each transmitting end device, it can send the second artificial noise signal to the transmitting end device according to the first signal. The feedback signal of the signal, the second artificial noise signal is used to interfere with the estimation accuracy of the second channel direction information by the eavesdropping end device, and at the same time, the eavesdropping end device will also listen to the receiving end device. After receiving the feedback signals returned by the receiving end device for a plurality of the first signals, the transmitting end device adjusts the first ( n+1) time slot sends the transmit weight of the third artificial noise signal to the receiving end device, so that the interference power of the third artificial noise signal at the receiving end device is minimized, so that distributed security communication can be improved system security.

Please refer to FIG. 2. FIG. 2 is a schematic flowchart of a security detection method for a distributed secure communication system disclosed by an embodiment of the present invention. Wherein, the security detection method of the distributed security communication system is applied to the eavesdropping terminal equipment included in the distributed security communication system. As shown in FIG. 2 , the security detection method of the distributed security communication system may include the following steps:

Step 201: The eavesdropping end device monitors multiple first signals sent by the transmitting end device to the receiving end device in the nth time slot.

The first signal includes a first artificial noise signal, wherein the nth time slot is the current time slot, and the n is a positive integer; multiple antennas are installed on the eavesdropping terminal device, and the multiple antennas are used for for receiving the first signal or the feedback signal.

In the embodiment of the present invention, the transmitting end device sends the first signal carrying the first artificial noise signal to the receiving end device in the nth time slot, which may be expressed as:

表示第i个分布式发射端设备发送保密信息的功率，

表示第i个分布式发射端设备发送的第一人造噪声信号，它服从均值为0，方差为1的高斯分布，

表示第i个发射端设备发送第一人造噪声

的功率。其中，所有分布式发射端设备在每一个时隙内发送保密信息x_C[n]的功率相同，发送第一人造噪声ξ_S,i[n]的功率相同，且它们满足如下条件：Among them, x _C [n] represents the confidential information sent in the nth time slot, and the confidential information sent by each distributed transmitter device in each time slot is the same,

represents the power of the i-th distributed transmitter device to send confidential information,

Represents the first artificial noise signal sent by the i-th distributed transmitter device, which obeys a Gaussian distribution with a mean of 0 and a variance of 1.

Indicates that the i-th transmitter device sends the first artificial noise

of power. Among them, all distributed transmitter devices transmit the secret information x _C [n] with the same power in each time slot, and send the first artificial noise ξ _S,i [n] with the same power, and they satisfy the following conditions:

表示第i个分布式发射端设备发送第一人造噪声ξ_S,i[n]的发射权值。当对每一个分布式发射端设备的发射相位进行优化时，该发射权值可表示为

Among them, P _T represents the upper limit of the sum of the power of each distributed transmitter device to send the secret information x _C [n] and the first artificial noise ξ _S,i [n].

Indicates the transmission weight of the i-th distributed transmitter device sending the first artificial noise ξ _S,i [n]. When optimizing the transmit phase of each distributed transmitting end device, the transmit weight can be expressed as

The receiving end device receives a plurality of first signals sent by the transmitting end device in the nth time slot, which can be expressed as

表示合法接收端D上的加性高斯白噪声(Additive WhiteGaussian Noise)，γ_SiD表示第i个分布式发射节点S_i与合法接收端D之间的未知相位，它服从[0,2π)间的均匀分布，ψ_SiD表示第i个发射节点S_i与合法接收端D之间第一阶段信道的相位响应。in

Represents the Additive White Gaussian Noise on the legal receiver D, and γ _SiD represents the unknown phase between the _i -th distributed transmitting node Si and the legal receiver D, which obeys the relationship between [0, 2π) Uniform distribution, ψ _SiD represents the phase response of the first-stage channel between the _ith transmitting node Si and the legitimate receiving end D.

The signal-to-interference-to-noise ratio of the receiving end device in the nth time slot can be expressed as:

The reception capacity R _D [n] between the transmitter device and the receiver device in the nth time slot can be expressed as:

R _D [n]=log ₂ (1+SINR _D [n])

In the embodiment of the present invention, the eavesdropping end device is also monitoring the signal sent by the transmitting end device to the receiving end device. When the eavesdropping end device is equipped with M receiving antennas, the receiving vector of the eavesdropping end device can be expressed as:

表示第i个发射端设备S_i到窃听端设备E的到达角，

表示窃听端设备E上对应的天线导向矢量(Steering Vector)。类似于γ_SiD和ψ_SiD的描述，

表示第i个发射端设备S_i与监听者E之间的未知相位，

表示第i个发射端设备S_i与窃听端设备E之间的相位响应。

是窃听端设备E上的接收噪声矢量，它服从分布

其中

是对角矩阵，主对线上的每一个元素代表窃听端设备E每一根接收天线上加性高斯白噪声的方差。in

represents the angle of arrival from the i-th transmitter device S _i to the eavesdropping device E,

Indicates the corresponding antenna steering vector (Steering Vector) on the eavesdropping end device E. Similar to the description of γ _SiD and ψ _SiD ,

represents the unknown phase between the i-th transmitter device S _i and the listener E,

Represents the phase response between the _i -th transmitting end device Si and the eavesdropping end device E.

is the received noise vector on the eavesdropping end device E, which obeys the distribution

in

is a diagonal matrix, and each element on the main pair line represents the variance of the additive white Gaussian noise on each receiving antenna of the eavesdropping end device E.

Step 202: The eavesdropping end device determines a first signal-to-interference and noise ratio SINR of the eavesdropping end device according to the first signal.

In this embodiment of the present invention, the eavesdropping end device E determines the first signal to interference and noise ratio SINR of the eavesdropping end device according to the first signal, which may be expressed as:

表示窃听端设备E上波束成型器的权值向量，w₁对应于

其中，

为窃听端设备上接收到的人工噪声信号的零陷角度，θ为固定值，

为对

的估计误差。in

represents the weight vector of the beamformer on the eavesdropping end device E, w ₁ corresponds to

in,

is the null angle of the artificial noise signal received on the eavesdropping end device, θ is a fixed value,

for right

estimation error.

Step 203: The eavesdropping end device determines the first eavesdropping capacity of the nth time slot of the eavesdropping end device according to the first SINR.

The eavesdropping end device E determines the first eavesdropping capacity of the nth time slot of the eavesdropping end device according to the first SINR and can be expressed as:

R _E1 = log ₂ (1+SINR _E1 )

的正态分布，其中，

SINR_E1为所述第一SINR，SINR_E2为所述窃听端设备第n时隙的第二SINR(具体参见图3中的相关描述)，k为常数，可选的，k可以根据具体波束成型算法确定。Wherein, the first eavesdropping capacity depends on the estimation error of the nulling angle of the first artificial noise signal sent by the eavesdropping end device to the nth time slot of the transmitting end device, and the estimated error obeys the mean value of 0, The variance is

the normal distribution of , where,

SINR _E1 is the first SINR, SINR _E2 is the second SINR of the nth time slot of the eavesdropping end device (for details, see the related description in FIG. 3 ), k is a constant, optionally, k can be based on specific beamforming Algorithm OK.

Step 204: The eavesdropping end device determines the security capacity of the receiving end device according to the first eavesdropping capacity and the acquired receiving capacity of the receiving end device.

In the embodiment of the present invention, after the receiving end device determines the receiving capacity RD [ _n ], the receiving end device can send the receiving end device to the eavesdropping end device, so that the eavesdropping end device can obtain the receiving end device's receiving capacity , and then determine the security capacity of the receiving end device, the security capacity R _S [n] on the receiving end device D can be expressed as:

R _S [n]=[R _D [n]-R _E [n]] ⁺

即保证接收端设备D上可实现的安全容量R_S≥0。in,

That is, the achievable security capacity R _S ≥ 0 on the receiving end device D is guaranteed.

Step 205: The eavesdropping terminal device detects the security of the distributed security communication system according to the changing trend of the security capacity.

In the embodiment of the present invention, the eavesdropping end device may compare the security capacity of the nth time slot of the receiving end device with the security capacity of the (n-1)th time slot of the receiving end device to determine the changing trend of the security capacity , the change trend may include increase or decrease. Further, the security of the distributed security communication system may be detected according to the change trend. Generally, if the security capacity of the receiving end device is increased, it can indicate that the distributed security The security of the communication system increases, on the contrary, if the security capacity of the receiver device decreases, it can indicate that the security of the distributed security communication system decreases.

In the method described in FIG. 2 , the eavesdropping end device may monitor a plurality of first signals sent by the transmitting end devices to the receiving end device in the nth time slot, and the first signals include a first artificial noise signal, wherein , the nth time slot is the current time slot, and the n is a positive integer; further, the eavesdropping end device can determine the first signal to interference and noise ratio SINR of the eavesdropping end device according to the first signal; The first SINR determines the first eavesdropping capacity of the nth time slot of the eavesdropping end device; further, the eavesdropping end device can determine the first eavesdropping capacity according to the first eavesdropping capacity and the acquired receiving capacity of the receiving end device. The security capacity of the receiving end device, and the security of the distributed secure communication system is detected according to the changing trend of the security capacity. It can be seen that, by implementing the embodiments of the present invention, the security of the distributed secure communication system can be detected by listening to the change trend of the security capacity of the receiving end device determined by the eavesdropping end device.

Please refer to FIG. 3. FIG. 3 is a schematic flowchart of another security detection method of a distributed security communication system disclosed in an embodiment of the present invention; wherein, the security detection method of the distributed security communication system is applied to distributed security communication The eavesdropping terminal device included in the system, as shown in Figure 3, the security detection method of the distributed security communication system may include the following steps:

Step 301: The eavesdropping end device monitors multiple first signals sent by the transmitting end device to the receiving end device in the nth time slot.

Step 302: The eavesdropping end device determines a first signal-to-interference and noise ratio SINR of the eavesdropping end device according to the first signal.

Step 303: The eavesdropping end device determines the first eavesdropping capacity of the nth time slot of the eavesdropping end device according to the first SINR.

Step 304: The eavesdropping end device determines the security capacity of the receiving end device according to the first eavesdropping capacity and the acquired receiving capacity of the receiving end device.

Step 305: The eavesdropping terminal device detects the security of the distributed security communication system according to the changing trend of the security capacity.

Step 306: The eavesdropping end device determines a first angle of arrival from each of the transmitting end devices to the eavesdropping end device according to the first signal, so as to estimate the direction angle from the transmitting end device to the receiving end device.

即第i个发射端设备S_i到窃听端设备E的到达角，然后可以根据这些到达角估计图1中的分布式发射端设备所在圆的圆心到接收端设备D的方向，即：In this embodiment of the present invention, the eavesdropping terminal device E can also be obtained according to multiple antennas.

That is, the angle of arrival of the i-th transmitter device S _i to the eavesdropping end device E, and then the direction from the center of the circle where the distributed transmitter device is located to the receiver device D in FIG. 1 can be estimated according to these angles of arrival, namely:

where _wi is determined by the listener E's estimation of the signal-to-noise ratio of the information sent by each distributed transmitting node to the legitimate receiving end D.

Step 307: The eavesdropping end device establishes a first beamformer for the first signal.

Wherein, when the eavesdropping end device E is equipped with multiple antennas, a beamformer can be established for the received first signal y _E1 according to the direction of the null angle, and the output can be expressed as:

表示第一阶段监听者E上波束成型器的权值向量。in

Represents the weight vector of the beamformer on the first stage listener E.

Step 308: The eavesdropping end device monitors the feedback signals sent by the receiving end device to the multiple transmitting end devices in the nth time slot.

The receiving end device receives a plurality of first signals sent by the transmitting end device in the nth time slot, which can be expressed as

表示合法接收端D上的加性高斯白噪声(Additive WhiteGaussian Noise)，γ_SiD表示第i个分布式发射节点S_i与合法接收端D之间的未知相位，它服从[0,2π)间的均匀分布，

表示第i个发射节点S_i与合法接收端D之间第一阶段信道的相位响应。in

Represents the Additive White Gaussian Noise on the legal receiver D, and γ _SiD represents the unknown phase between the _i -th distributed transmitting node Si and the legal receiver D, which obeys the relationship between [0, 2π) Evenly distributed,

represents the phase response of the first-stage channel between the _i -th transmitting node Si and the legitimate receiver D.

The feedback signal sent by the receiver device to multiple transmitter devices in the nth time slot can be expressed as:

其中，接收端设备只需要反馈单比特控制信息，能够节省网络资源。where P _C2 represents the transmit power of the single-bit control information x _B [n] fed back by the receiver device D, P _ξ2 represents the power of the receiver device D to transmit the second artificial noise signal ξ _D [n],

The receiving end device only needs to feed back single-bit control information, which can save network resources.

The eavesdropping end device listening to the feedback signals sent by the receiving end device to the multiple transmitting end devices in the nth time slot can be expressed as:

时的到达角，

是监听者E上对应的天线导向矢量，γ_DE表示监听者E与合法接收端D之间未知的相位，它服从[0,2π)间的均匀分布，ψ_DE表示合法接收端D与监听者E之间在第二阶段的信道相位响应。

表示第二阶段监听者E上的接收噪声矢量，它服从分布

其中

是对角矩阵，主对线上的每一个元素代表监听者E每一根接收天线上加性高斯白噪声的方差。where θ _DE indicates that the listener E receives the feedback signal from the legitimate receiver D

angle of arrival at ,

is the corresponding antenna steering vector on the listener E, γ _DE represents the unknown phase between the listener E and the legal receiver D, which obeys the uniform distribution between [0, 2π), ψ _DE represents the legal receiver D and the listener D The channel phase response in the second stage between E.

represents the received noise vector on the second-stage listener E, which obeys the distribution

in

is a diagonal matrix, and each element on the main pair line represents the variance of the additive white Gaussian noise on each receiving antenna of listener E.

As an optional embodiment, the method may also include the following steps:

11) according to the feedback signal, determine the second angle of arrival from the receiving end device to the eavesdropping end device;

12) According to the first angle of arrival and the second angle of arrival, determine the third angle of arrival from the transmitting end device to the receiving end device;

13) Adjust the receiving beam weight of the first beamformer of the eavesdropping terminal device according to the third angle of arrival.

In this optional implementation manner, the eavesdropping end device may determine the first angle of arrival from each of the transmitting end devices to the eavesdropping end device according to the first signal, and the eavesdropping end device may also determine the first angle of arrival according to the feedback signal. The second angle of arrival from the receiving end device to the eavesdropping end device, further, the eavesdropping end device may determine the distance from the transmitting end device to the receiving end device according to the first angle of arrival and the second angle of arrival and adjust the receiving beam weight of the first beamformer of the eavesdropping device according to the third angle of arrival, so that the eavesdropping device can convert the first beamformer of the eavesdropping device The receiving beam is aligned in the direction from the transmitting end device to the receiving end device, which can increase the eavesdropping capacity of the eavesdropping end device, thereby making the security detection of the distributed secure communication system more effective.

Step 309: The eavesdropping end device establishes a second beamformer for the feedback signal.

Wherein, the eavesdropping end device E can establish a second beamformer for the received feedback signal y _E2 , and the output can be expressed as:

代表第二阶段监听者E上的权值向量。in

Represents the weight vector on the second-stage listener E.

Step 310: The eavesdropping end device determines the second SINR of the eavesdropping end device according to the feedback signal.

Wherein, the eavesdropping end device determines the second SINR of the eavesdropping end device according to the feedback signal, which can be expressed as:

Please refer to FIG. 4 , FIG. 5 and FIG. 6 together, wherein FIG. 4 is a schematic diagram of the convergence of an artificial noise signal under different estimation errors disclosed in an embodiment of the present invention; FIG. 5 is a distribution disclosed in an embodiment of the present invention. Figure 6 is a schematic diagram of the convergence of the security capacity of another distributed security communication system disclosed in an embodiment of the present invention. As shown in FIG. 4 and FIG. 5 , the convergence of the received signal strength (Received Signal Strength, RSS) of the artificial noise signal received by the eavesdropping end device is different under different estimation errors. When the estimated error of the null angle of the first artificial noise signal sent in the nth time slot is different, the security capacity of the distributed secure communication system is different. The estimation accuracy of information, the greater the safety capacity of the distributed safety communication system, that is, the higher the safety of the distributed safety communication system. As shown in Figure 6, the number of antennas installed on the eavesdropping terminal equipment is different, and the security capacity of the distributed security communication system is different. The more antennas installed, the lower the security capacity of the distributed security communication system, that is, the distributed security communication system. On the contrary, the fewer antennas are installed, the higher the safety capacity of the distributed safety communication system, that is, the higher the safety of the distributed safety communication system.

In the method described in FIG. 3 , the eavesdropping end device may determine the first angle of arrival from each of the transmitting end devices to the eavesdropping end device according to the first signal, and establish a first angle of arrival for the first signal. Beamformer, in addition, the eavesdropping end device can also determine the second SINR of the eavesdropping end device according to the feedback signals sent by the receiving end device to a plurality of the transmitting end devices in the nth time slot; and The feedback signal establishes a second beamformer.

Please refer to FIG. 7. FIG. 7 is a schematic structural diagram of a security detection apparatus disclosed in an embodiment of the present invention. Wherein, the security detection device described in FIG. 7 may be used to execute some or all of the steps in the security detection method of the distributed security communication system described in FIG. 2 or FIG. 3 . For details, please refer to FIG. 2 or FIG. Relevant descriptions are not repeated here. As shown in Figure 7, the security detection device may include:

A monitoring unit 701, configured to monitor a plurality of first signals sent by the transmitting end devices to the receiving end devices in the nth time slot, where the first signals include a first artificial noise signal, wherein the nth time slot is the current time slot, and the n is a positive integer;

A determining unit 702, configured to determine the first signal-to-interference-to-noise ratio SINR of the eavesdropping terminal device according to the first signal;

The determining unit 702 is further configured to determine the first eavesdropping capacity of the nth time slot of the eavesdropping terminal device according to the first SINR;

The determining unit 702 is further configured to determine the security capacity of the receiving end device according to the first eavesdropping capacity and the obtained receiving capacity of the receiving end device;

The detection unit 703 is configured to detect the security of the distributed security communication system according to the change trend of the security capacity.

Wherein, by implementing the security detection apparatus described in FIG. 7 , the security of the distributed security communication system can be detected by the change trend of the security capacity of the receiving end device determined by the eavesdropping end device.

Please refer to FIG. 8 . FIG. 8 is a schematic structural diagram of another security detection apparatus disclosed in an embodiment of the present invention. Wherein, the security detection device described in FIG. 8 can be used to execute some or all of the steps in the security detection method of the distributed security communication system described in FIG. 2 or FIG. 3 . For details, please refer to FIG. 2 or FIG. 3 Relevant descriptions are not repeated here. Wherein, the safety detection device described in FIG. 8 is further optimized on the basis of the safety detection device described in FIG. 7 . Compared with the safety detection device described in FIG. 7 ,

The determining unit 702 is further configured to determine, according to the first signal, the first angle of arrival of each of the transmitting end devices to the eavesdropping end device, so as to estimate the distance between the transmitting end device and the receiving end device. direction angle;

The security detection device described in FIG. 8 also includes:

A establishing unit 704, configured to establish a first beamformer for the first signal.

The monitoring unit 701 is further configured to monitor feedback signals sent by the receiving end device to a plurality of the transmitting end devices in the nth time slot;

The establishing unit 704 is further configured to establish a second beamformer for the feedback signal;

The determining unit 702 is further configured to determine the second SINR of the eavesdropping terminal device according to the feedback signal.

Optionally, the determining unit 702 is further configured to determine the second angle of arrival from the receiving end device to the eavesdropping end device according to the feedback signal;

The determining unit 702 is further configured to determine a third angle of arrival from the transmitting end device to the receiving end device according to the first angle of arrival and the second angle of arrival;

The safety detection device also includes:

The adjustment unit 705 is configured to adjust the receiving beam weight of the first beamformer of the eavesdropping end device according to the third angle of arrival.

的正态分布，其中，

SINR_E1为所述第一SINR，SINR_E2为所述第二SINR，k为常数。Wherein, the first eavesdropping capacity depends on the estimation error of the nulling angle of the first artificial noise signal sent by the eavesdropping end device to the nth time slot of the transmitting end device, and the estimated error obeys the mean value of 0, The variance is

the normal distribution of , where,

SINR _E1 is the first SINR, SINR _E2 is the second SINR, and k is a constant.

Wherein, multiple antennas are installed on the eavesdropping terminal device, and the multiple antennas are used to receive the first signal or the feedback signal.

Wherein, by implementing the security detection apparatus described in FIG. 8 , the security of the distributed security communication system can be detected by the change trend of the security capacity of the receiving end device determined by the eavesdropping end device.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative, for example, the division of the units is only a logical function division, and there may be other division methods in actual implementation, for example, multiple units or components may be combined or Integration into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated unit, if implemented as a software functional unit and sold or used as a stand-alone product, may be stored in a computer-readable memory. Based on such understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a memory, Several instructions are included to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned memory includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable memory, and the memory can include: a flash disk , Read-only memory (English: Read-Only Memory, referred to as: ROM), random access device (English: Random Access Memory, referred to as: RAM), magnetic disk or optical disk, etc.

The security detection method and device for a distributed security communication system disclosed in the embodiments of the present invention have been described in detail above. The principles and implementations of the present invention are described in this paper by using specific examples. The descriptions of the above embodiments are only It is used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific embodiments and application scope. The contents of the description should not be construed as limiting the present invention.

Claims (6)

1. the safety detection method of a distributed safety communication system, is characterized in that, is applied to the eavesdropping terminal equipment that distributed safety communication system comprises, and described distributed safety communication system also comprises a plurality of transmitting terminal equipment and receiving terminal equipment , the method includes: Monitoring multiple first signals sent by the transmitting end device to the receiving end device in the nth time slot, the first signals include a first artificial noise signal, wherein the nth time slot is the current time slot, so Said n is a positive integer; According to the first signal, the first signal-to-interference and noise ratio SINR of the eavesdropping terminal device is determined, and the first signal satisfies:

The first signal-to-interference-to-noise ratio SINR satisfies:

According to the first SINR, determine the first eavesdropping capacity of the nth time slot of the eavesdropping terminal device, and the first eavesdropping capacity satisfies: R _E1 =log ₂ (1+SINR _E1 ); According to the first eavesdropping capacity and the acquired receiving capacity of the receiving end device, the security capacity of the receiving end device is determined, and the signal-to-interference and noise ratio of the receiving end device in the nth time slot satisfies:

The receiving capacity of the receiving end device satisfies: R _D [n]=log ₂ (1+SINR _D [n]), and the security capacity of the receiving end device satisfies: R _S [n]=[R _D [n] -R _E [n]] ⁺ ; Detecting the security of the distributed security communication system according to the changing trend of the security capacity; According to the first signal, determine the first angle of arrival of each of the transmitting end equipment to the eavesdropping end device, to estimate the direction angle from the transmitting end device to the receiving end device; establishing a first beamformer for the first signal; monitoring the feedback signals sent by the receiving end device to a plurality of the transmitting end devices in the nth time slot; establishing a second beamformer for the feedback signal; According to the feedback signal, the second SINR of the eavesdropping terminal device is determined, and the second SINR satisfies:

in,

represents the power of the i-th distributed transmitter device to send confidential information, x _C [n] represents the confidential information sent in the n-th time slot,

Indicates that the i-th transmitter device sends the first artificial noise

power,

Represents the first artificial noise signal sent by the i-th distributed transmitter device, which obeys a Gaussian distribution with a mean of 0 and a variance of 1.

Represents the transmission weight of the i-th distributed transmitter device sending the first artificial noise ξ _S,i [n], P _C1 represents the power of the transmitter device to send the first signal, P _ε1 represents the transmitter device sends the first artificial noise power,

represents the free space path loss from the i-th transmitter device to the receiver device,

represents the channel fading from the i-th transmitter device to the receiver device,

represents the angle of arrival from the i-th transmitter device to the eavesdropping device,

Represents the corresponding antenna steering vector on the eavesdropping end device, M represents the number of receiving antennas equipped on the eavesdropping end device,

represents the weight vector of the beamformer on the eavesdropping end device,

is a diagonal matrix, each element on the main pair line represents the variance of the additive white Gaussian noise on each receiving antenna of the eavesdropping device, PC represents the power of the first signal sent by the transmitting device, and _{P ε} represents the transmitting device. The power of the transmitted first artificial noise, w _{S, i} and

Represents the emission weight of the first artificial noise sent by the i-th distributed transmitter device, the additive white Gaussian noise on the receiver device obeys the mean value of 0, and the variance is

the Gaussian distribution of ,

Expressed as variance, P _C2 represents the power of the second SINR sent by the transmitter device, L _DE represents the free space path loss between the receiver device D and the eavesdropping device E, and h _DE represents the receiver device D and the eavesdropping device E. The channel fading between , θ _DE represents the angle of arrival when the eavesdropping end device E receives the feedback signal from the legitimate receiving end device D,

is the corresponding antenna steering vector on the eavesdropping end device E, M represents the number of receiving antennas equipped by the eavesdropping end device,

represents the weight vector on the second-stage eavesdropping device,

is a diagonal matrix, each element on the main pair line represents the variance of the additive white Gaussian noise on each receiving antenna of the eavesdropping end device E, P _ξ2 represents the second artificial noise signal ξ _D [n] emitted by the receiving end device D power,

2. The method according to claim 1, wherein the method further comprises: According to the feedback signal, determine the second angle of arrival from the receiving end device to the eavesdropping end device; Determine the third angle of arrival from the transmitting end device to the receiving end device according to the first angle of arrival and the second angle of arrival; According to the third angle of arrival, the receiving beam weight of the first beamformer of the eavesdropping end device is adjusted. 3. The method according to claim 1, wherein the first eavesdropping capacity depends on the nulling angle at which the eavesdropping terminal device sends the first artificial noise signal to the nth time slot of the transmitting terminal device The estimation error of , the estimation error obeys the mean of 0, and the variance is

the normal distribution of , where,

SINR _E1 is the first SINR, SINR _E2 is the second SINR, and k is a constant. The method according to any one of claims 1 to 3, wherein a plurality of antennas are installed on the eavesdropping terminal device, and the plurality of antennas are used to receive the first signal or the feedback signal . 5. A security detection device, characterized in that, running on the wiretapping terminal equipment included in the distributed security communication system, comprising: a monitoring unit, configured to monitor the first signal sent by multiple transmitter devices to the receiver device in the nth time slot, where the first signal includes a first artificial noise signal, wherein the nth time slot is the current time slot, The n is a positive integer; The monitoring unit is further configured to monitor feedback signals sent by the receiving end device to a plurality of the transmitting end devices in the nth time slot; A determination unit, configured to determine the first signal-to-interference-to-noise ratio SINR of the eavesdropping terminal device according to the first signal, where the first signal satisfies:

The first signal-to-interference-to-noise ratio SINR satisfies:

The determining unit is further configured to determine, according to the first SINR, a first eavesdropping capacity of the nth time slot of the eavesdropping terminal device, where the first eavesdropping capacity satisfies: R _E1 =log ₂ (1+SINR _E1 ) ; The determining unit is further configured to determine the security capacity of the receiving end device according to the first eavesdropping capacity and the acquired receiving capacity of the receiving end device, and the signal interference of the receiving end device in the nth time slot. The noise ratio meets:

The receiving capacity of the receiving end device satisfies: R _D [n]=log ₂ (1+SINR _D [n]), and the security capacity of the receiving end device satisfies: R _S [n]=[R _D [n] -R _E [n]] ⁺ ; The determining unit is further configured to determine, according to the first signal, a first angle of arrival from each of the transmitting end devices to the eavesdropping end device, so as to estimate a direction angle from the transmitting end device to the receiving end device ; The determining unit is further configured to determine the second SINR of the eavesdropping terminal device according to the feedback signal, where the second SINR satisfies:

a establishing unit for establishing a first beamformer for the first signal; The establishing unit is further configured to establish a second beamformer for the feedback signal; a detection unit, configured to detect the security of the distributed security communication system according to the changing trend of the security capacity, in,

represents the power of the i-th distributed transmitter device to send confidential information, x _C [n] represents the confidential information sent in the n-th time slot,

Indicates that the i-th transmitter device sends the first artificial noise

power,

Represents the first artificial noise signal sent by the i-th distributed transmitter device, which obeys a Gaussian distribution with a mean of 0 and a variance of 1.

Represents the transmission weight of the i-th distributed transmitter device sending the first artificial noise ξ _S,i [n], P _C1 represents the power of the transmitter device to send the first signal, P _ε1 represents the transmitter device sends the first artificial noise power,

represents the free space path loss from the i-th transmitter device to the receiver device,

represents the channel fading from the i-th transmitter device to the receiver device,

represents the angle of arrival from the i-th transmitter device to the eavesdropping device,

Represents the corresponding antenna steering vector on the eavesdropping end device, M represents the number of receiving antennas equipped by the eavesdropping end device,

represents the weight vector of the beamformer on the eavesdropping end device,

is a diagonal matrix, each element on the main pair line represents the variance of the additive white Gaussian noise on each receiving antenna of the eavesdropping device, PC represents the power of the first signal sent by the transmitting device, and _{P ε} represents the transmitting device. The power of the transmitted first artificial noise, w _{S, i} and

Represents the emission weight of the first artificial noise sent by the i-th distributed transmitter device, the additive white Gaussian noise on the receiver device obeys the mean value of 0, and the variance is

the Gaussian distribution of ,

Expressed as variance, P _C2 represents the power of the second SINR sent by the transmitter device, L _DE represents the free space path loss between the receiver device D and the eavesdropping device E, and h _DE represents the receiver device D and the eavesdropping device E. The channel fading between , θ _DE represents the arrival angle when the eavesdropping end device E receives the feedback signal from the legitimate receiving end device D,

is the corresponding antenna steering vector on the eavesdropping end device E, M represents the number of receiving antennas equipped by the eavesdropping end device,

represents the weight vector on the second-stage eavesdropping device,

is a diagonal matrix, each element on the main pair line represents the variance of the additive white Gaussian noise on each receiving antenna of the eavesdropping end device E, P _ξ2 represents the second artificial noise signal ξ _D [n] emitted by the receiving end device D power,

6. The security detection device according to claim 5, wherein the determining unit is further configured to determine the second angle of arrival from the receiving end device to the eavesdropping end device according to the feedback signal; The determining unit is further configured to determine a third angle of arrival from the transmitting end device to the receiving end device according to the first angle of arrival and the second angle of arrival; The safety detection device also includes: An adjustment unit, configured to adjust the receiving beam weight of the first beamformer of the eavesdropping terminal device according to the third angle of arrival.

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