WO2019006716A1 - Method and apparatus for detecting security of distributed secure communication system - Google Patents

Abstract

The present invention provides a method and apparatus for detecting the security of a distributed secure communication system. The method comprises : listening for first signals sent by multiple transmitting end devices to a receiving end device on a nth timeslot, the first signals comprising first artificial noise signals, the nth timeslot being a current timeslot, and n being a positive integer; determining a first signal to interference plus noise ratio (SINR) of an eavesdropping end device according to the first signals, and determining a first eavesdropping capacity of the eavesdropping end device on a nth timeslot according to the first SINR; determining a security capacity of the receiving end device according to the first eavesdropping capacity and an obtained receiving capacity of the receiving end device; and detecting the security of a distributed secure communication system according to a change trend of the security capacity, and adjusting a receiving beam weight of a beamforming device of the eavesdropping end device according to a third arrival angle from the transmitting end devices to the receiving end device. By means of embodiments of the preset invention, the security of the distributed secure communication system can be detected.

Description

Security detection method and device for distributed secure communication system Technical field

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

Background technique

Distributed Beamforming is a cooperative communication technology in which multiple transmitting devices transmit the same information to the target device and control the transmitting phase of the transmitting device to make the signals of multiple transmitting devices at the target end. The device is effectively merged.

The current communication environment is generally complicated. When there is a 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, thereby adjusting its own beamformer to make itself The eavesdropping capacity is increased, so that the security of the distributed secure communication system is degraded. How to detect the security of distributed secure communication systems is a technical issue to be solved urgently.

Summary of the invention

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

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

Listening to the first signal sent by the multiple transmitting end devices to the receiving end device in the nth time slot, where the first signal includes a first artificial noise signal, where the nth time slot is a current time slot, Said n is a positive integer;

Determining, according to the first signal, a first signal to interference and noise ratio SINR of the eavesdropping device;

Determining, according to the first SINR, a first eavesdropping capacity of the nth time slot of the eavesdropping device;

Determining a security capacity of the receiving end device according to the first eavesdropping capacity and the received receiving capacity of the receiving end device;

The security of the distributed secure communication system is detected according to the changing trend of the security capacity.

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

Determining, according to the first signal, a first angle of arrival of each of the transmitting end devices to the eavesdropping device to estimate a direction angle of 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 embodiments of the present invention, the method further includes:

Listening to the feedback signal sent by the receiving end device to the plurality of the transmitting end devices in the nth time slot,

Establishing a second beamformer for the feedback signal;

Determining, according to the feedback signal, a second SINR of the eavesdropping device.

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

Determining, according to the feedback signal, a second angle of arrival of the receiving device to the eavesdropping device;

Determining, according to the first angle of arrival and the second angle of arrival, a third angle of arrival of the transmitting device to the receiving device;

And adjusting a receive beam weight of the first beamformer of the eavesdropping 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 first aspect of the embodiments of the present invention, the first eavesdropping capacity is determined by the eavesdropping device transmitting the first artificial noise signal to the nth time slot of the transmitting end device. Estimation error of the null angle, the estimated error obeys a mean of 0, and the variance is

Normal distribution, where

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

As an optional implementation manner, in a first aspect of the embodiments of the present invention, the eavesdropping device is installed with multiple antennas, and the multiple antennas are configured to receive the first signal or the feedback signal.

The second aspect of the embodiment of the present invention discloses a security detecting device, which is operated by the eavesdropping device included in the distributed secure communication system, and includes:

a monitoring unit, configured to monitor a first signal sent by the multiple transmitting end devices to the receiving end device in an nth time slot, where the first signal includes a first artificial noise signal, where the nth time slot is The current time slot, the n is a positive integer;

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

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 device;

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

And a detecting unit, configured to detect the security of the distributed secure communication system according to the changing trend of the security capacity.

As an optional implementation manner, in a second aspect of the embodiments of the present invention, the determining unit is further configured to determine, according to the first signal, a first one of each of the transmitting end devices to the eavesdropping device An angle of arrival to estimate a direction angle of the transmitting end device to the receiving end device;

The security detecting device further includes:

And 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 listening unit is further configured to monitor, by the nth time slot, the feedback signal sent by the receiving end device to the multiple sending end devices. number;

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

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

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 feedback signal, a second angle of arrival of the receiving device to the eavesdropping device ;

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

The security detecting device further includes:

And an adjusting unit, configured to adjust a received beam weight of the first beamformer of the eavesdropping 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 is determined by the eavesdropping device transmitting the first artificial noise signal to the nth time slot of the transmitting end device. Estimation error of the null angle, the estimated error obeys a mean of 0, and the variance is

Normal distribution, where

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

As an optional implementation manner, in a second aspect of the embodiments of the present invention, the eavesdropping device is configured with multiple antennas, and the multiple antennas are configured to receive the first signal or the feedback signal.

Compared with the prior art, the embodiment of the invention has the following beneficial effects:

In the embodiment of the present invention, the eavesdropping device can monitor the first signal sent by the multiple transmitting end devices to the receiving end device in the nth time slot, where the first signal includes a first artificial noise signal, where the The nth time slot is the current time slot, and the n is a positive integer; further, the eavesdropping device can determine the first signal to interference and noise ratio SINR of the eavesdropping device according to the first signal; a SINR, determining a first eavesdropping capacity of the nth time slot of the eavesdropping device; further The eavesdropping device may determine the security capacity of the receiving end device according to the first eavesdropping capacity and the received receiving capacity of the receiving end device, and according to the changing trend of the security capacity, the distributed The security of the secure communication system is detected. It can be seen that, in the embodiment of the present invention, the security of the distributed secure communication system can be detected by the trend of the security capacity of the receiving end device determined by the eavesdropping device.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings to be used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without paying any creative work.

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

2 is a schematic flowchart of a security detection method of a distributed secure communication system according to an embodiment of the present invention;

3 is a schematic flowchart of a security detection method of another distributed secure communication system according to an embodiment of the present invention;

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

FIG. 5 is a schematic diagram of convergence of a security capacity of a distributed secure communication system according to an embodiment of the present invention; FIG.

6 is a schematic diagram of convergence of a security capacity of another distributed secure communication system according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a security detecting apparatus according to an embodiment of the present invention; FIG.

FIG. 8 is a schematic structural diagram of another security detecting apparatus according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and It is the entire embodiment. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

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

The embodiment of the invention discloses a security detection method and device for a distributed secure communication system, which can detect the security of the distributed secure communication system. The details are described below in conjunction with the drawings.

Referring to FIG. 1, FIG. 1 is a schematic diagram of a model of a distributed secure communication system according to 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 a eavesdropping device E. Each of the transmitting end devices S _i and the receiving end device D is equipped with a single antenna, and the eavesdropping device E is equipped with multiple antennas.

The transmitting device S _{i is} mainly used for transmitting and receiving signals, such as transmitting an artificial noise signal and receiving a feedback signal, and the transmitting device S _i may be a base station. A base station (e.g., an access point) can refer to a device in an access network that communicates with a wireless terminal over one or more sectors over an air interface. The base station can be used to convert the received air frame to the IP packet as a router between the wireless terminal and the rest of the access network, wherein the remainder of the access network can include an Internet Protocol (IP) network. The base station can 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, or may be a base station (NodeB) in WCDMA, or may be an evolved base station in LTE (NodeB or eNB or e-NodeB, evolutional Node B), the embodiment of the present invention is not limited.

The receiving device D is mainly used for transmitting and receiving signals, such as transmitting an artificial noise signal and receiving a useful signal, and the target device D may be a base station.

The eavesdropping device E is mainly used for monitoring the signal sent by the transmitting end device S _i to the receiving end device D, and monitoring the signal sent by the receiving end device D to the transmitting end device S _i , and adjusting 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。

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，

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 FIG. 1, the coordinates of the receiving device D are represented as (0, r _D ), and the coordinates of the eavesdropping device E are expressed as (r _E sin θ _E , r _E cos θ _E ), where θ _E represents the angle between the eavesdropping device E and the y-axis at the coordinates shown in FIG. N distributed transmitting devices that have been frequency-synchronized are randomly distributed in a circle with a radius of r _S , and the distribution rules of these transmitting devices are uniformly distributed, that is, each distributed transmitting device appears at any position in the circle. The probability is the same. The coordinates of the i-th transmitting end device S _i (i=1, 2, K, N) can be expressed as

Therefore, the free space path loss of the i-th transmitting end device to the receiving end device D is

Where λ represents the carrier wavelength,

Indicates the distance from the i-th transmitter device to the sink device D.

Indicates channel fading from the i-th transmitter device to the sink device D.

Indicates the free space path loss of the i-th transmitter device to the eavesdropping device E,

Indicates the distance from the i-th transmitter device to the eavesdrop device E.

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

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

It indicates the free space path loss, distance, and channel fading between the receiving device D and the ith transmitting device when transmitting the feedback signal, respectively.

Wherein, any of the distributed transmitting end devices S _i (i=1, 2, K, N) and the receiving end device D are equipped with an omnidirectional single antenna, and the eavesdropping device E is equipped with a multi-antenna array to obtain more Channel direction information, thereby improving the eavesdropping capacity of the eavesdropping device E itself, for example by estimating the Direction of Arrival between the distributed transmitting device and the receiving device D to design its own beamformer.

In the distributed secure 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 an nth time slot, the first artificial The noise signal is used to interfere with the estimation accuracy of the first channel direction information by the eavesdropping device; at the same time, the eavesdropping device also monitors the first signal sent by each transmitting end device to the receiving end device, and according to the receiving The received signal establishes a first beamformer; after receiving the first signal carried by each transmitting device and carrying the first artificial noise signal, the receiving device can send the second signal to the transmitting device according to the first signal. a feedback signal of the artificial noise signal, the second artificial noise signal is used to interfere with the estimation accuracy of the second channel direction information by the eavesdropping device, and the eavesdropping device also monitors the receiving device to send to each a feedback signal of the transmitting device, and establishing a second beamformer according to the feedback signal; after receiving the feedback signal returned by the receiving device for the plurality of the first signals, the transmitting device adjusts according to the feedback signal Transmitting, by the (n+1)th time slot, a transmission weight of the third artificial noise signal to the receiving end device, so that the third artificial noise signal Interference power in the receiving terminal apparatus minimized, thereby improving the security of a distributed security communication system.

Referring to FIG. 2, FIG. 2 is a schematic flowchart diagram of a security detection method of a distributed secure communication system according to an embodiment of the present invention. The security detection method of the distributed secure communication system is applied to the eavesdropping device included in the distributed secure communication system. As shown in FIG. 2, the security detection method of the distributed secure communication system may include the following steps:

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

The first signal includes a first artificial noise signal, where the nth time slot is a current time slot, and the n is a positive integer; the eavesdropping device is equipped with multiple antennas, and the multiple antennas are used by the antenna Receiving the first signal or the feedback signal.

In the embodiment of the present invention, the transmitting, by the transmitting device, the first signal carrying the first artificial noise signal to the receiving device in the nth time slot 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

的功率相同，且它们满足如下条件：Where x _C [n] represents the secret information transmitted in the nth time slot, and the secret information transmitted by each distributed transmitting end device in each time slot is the same.

Indicates the power of the i-th distributed transmitting device to send confidential information.

Representing the first artificial noise signal transmitted by the ith distributed transmitting device, which obeys a Gaussian distribution with a mean of 0 and a variance of 1.

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

Power. Wherein all distributed transmitting devices transmit the same secret power x _C [n] in each time slot, and transmit the first artificial noise

The power is the same, and they meet 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

Where P _T represents the upper limit of the sum of the power of the secret information x _C [n] and the first artificial noise ξ _{S, i} [n] transmitted by each distributed transmitting device.

Indicates the transmission weight of the first artificial transmitting device 发送_S,i [n] transmitted by the i-th distributed transmitting device. When the transmit phase of each distributed transmitting device is optimized, the transmit weight can be expressed as

Receiving, by the receiving end device, the first signal sent by the multiple transmitting end devices 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 White Gaussian Noise)，

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。among them

Indicates Additive White Gaussian Noise on the legal receiver D.

Representing the unknown phase between the i-th distributed transmitting node S _i and the legal receiving end D, which obeys a uniform distribution between [0, 2π),

Indicates the phase response of the first phase channel between the i-th transmitting node S _i and the legal receiving end D.

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

The receiving capacity R _D [n] between the transmitting device and the receiving 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 device is also monitored by the transmitting end device and sent to the receiving end device. Signal, when the eavesdropping device is equipped with M receiving antennas, the receiving vector of the eavesdropping 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

和

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ε_E1～CN(0,Φ_E1)，其中Φ_E1∈□^M×M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。among them

Representing the angle of arrival of the i-th transmitting device S _i to the eavesdropping device E,

Indicates the corresponding antenna steering vector (Steering Vector) on the eavesdropping device E. Similar to

with

description of,

Indicates the unknown phase between the ith transmitter device S _i and the listener E,

Indicates the phase response between the i-th transmitting device S _i and the eavesdropping device E.

Is the receiving noise vector on the eavesdropping device E, which obeys the distribution ε _E1 ～ CN(0, Φ _E1 ), where Φ _E1 ∈ □ ^{M × M} is a diagonal matrix, and each element on the main pair represents the eavesdropping device E The variance of the additive white Gaussian noise on each of the receiving antennas.

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

In the embodiment of the present invention, the eavesdropping device E determines that the first signal to interference and noise ratio SINR of the eavesdropping device can be expressed as:

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。Where w ₁ ∈ □ ^{M × 1} represents the weight vector of the beamformer on the eavesdropping device E, w ₁ corresponds to

among them,

In order to eavesdrop the angle of the artificial noise signal received on the end device, θ is a fixed value.

Right

Estimated error.

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

The eavesdropping device E determines, according to the first SINR, that the first eavesdropping capacity of the nth time slot of the eavesdropping device 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。The first eavesdropping capacity depends on the estimation error of the eavesdropping device transmitting the null angle of the first artificial noise signal to the nth time slot of the transmitting end device, and the estimated error obeys a mean value of 0. Variance is

Normal distribution, where

SINR _E1 is the first SINR, SINR _E2 is the second SINR of the nth slot of the eavesdropping device (refer to the related description in FIG. 3), k is a constant, and optionally, k can be formed according to specific beamforming. The algorithm determines.

Step 204: The eavesdropping 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 determining the receiving capacity R _D [n], the receiving device can send the receiving capacity to the eavesdropping device, so that the eavesdropping device can obtain the receiving capacity of the receiving device. And determining the security capacity of the receiving device, and the security capacity R _S [n] on the receiving device D can be expressed as:

R _S [n]=[R _D [n]-R _E [n]] ⁺

Where [x] ⁺ □max{0, x}, that is, the safe capacity R _S ≥ 0 achievable on the receiving device D is guaranteed.

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

In an embodiment of the present invention, the eavesdropping 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 a change trend of the security capacity. The change trend may include an increase or decrease. Further, the security of the distributed secure communication system may be detected according to the change trend. Generally, if the security capacity of the receiving end device is increased, the distributed security may be indicated. The security of the communication system is increased. Conversely, if the security capacity of the receiving device is decreased, it can be indicated that the security of the distributed secure communication system is reduced.

In the method described in FIG. 2, the eavesdropping device can monitor the first signal sent by the plurality of transmitting end devices to the receiving end device in the nth time slot, where the first signal includes a first artificial noise signal, where The nth time slot is a current time slot, and the n is a positive integer. Further, the eavesdropping device may determine, according to the first signal, a first signal to interference and noise ratio SINR of the eavesdropping device; Determining, by the first SINR, a first eavesdropping capacity of the nth time slot of the eavesdropping device; further, the eavesdropping device may be configured according to the first eavesdropping capacity and the obtained receiving end The receiving capacity of the device determines the security capacity of the receiving device, and detects the security of the distributed secure communication system according to the changing trend of the security capacity. It can be seen that, in the embodiment of the present invention, the security of the distributed secure communication system can be detected by the trend of the security capacity of the receiving end device determined by the eavesdropping device.

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

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

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

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

Step 304: The eavesdropping 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 device detects the security of the distributed secure communication system according to the changing trend of the security capacity.

Step 306: The eavesdropping device determines, according to the first signal, a first angle of arrival of each of the transmitting end devices to the eavesdropping device to estimate a direction angle of 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 the embodiment of the present invention, the eavesdropping device E can also be obtained according to multiple antennas.

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

Where w _{i is} determined by the estimate of the signal-to-noise ratio of the information transmitted by the listener E to each of the distributed transmitting nodes to the legitimate receiving end D.

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

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

Where w ₁ ∈ □ ^{M × 1} represents the weight vector of the beamformer on the first stage listener E.

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

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

表示合法接收端D上的加性高斯白噪声(Additive White Gaussian Noise)，

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。among them

Indicates Additive White Gaussian Noise on the legal receiver D.

Representing the unknown phase between the i-th distributed transmitting node S _i and the legal receiving end D, which obeys a uniform distribution between [0, 2π),

Indicates the phase response of the first phase channel between the i-th transmitting node S _i and the legal receiving end D.

The feedback signal sent by the receiving end device to the plurality of transmitting end devices in the nth time slot may be expressed as:

Wherein P _C2 indicates that the receiving device D feeds back the transmission power of the single bit control information x _B [n], and P _{ξ 2} indicates that the receiving device D transmits the power of the second artificial noise signal ξ _D [n], ξ _D [n] ～ CN (0,1). The receiving end device only needs to feed back single-bit control information, which can save network resources.

The feedback signal sent by the eavesdropping device to the nth time slot by the receiving end device to the plurality of the transmitting end devices may 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ε_E2～CN(0,Φ_E2)，其中Φ_E2∈□^M×M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 q _DE indicates that the listener E receives the legal receiver D feedback signal

Angle of arrival,

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, it obeys a uniform distribution between [0, 2π), ψ _DE represents the legal receiver D and the listener Channel phase response between E in the second phase.

Represents the received noise vector on the second stage listener E, which obeys the distribution ε _E2 ～ CN(0, Φ _E2 ), where Φ _E2 ∈ □ ^{M × M} is a diagonal matrix, and each element on the main pair represents the listener The variance of the additive white Gaussian noise on each of the receiving antennas.

As an optional implementation manner, the method may further include the following steps:

11) determining, according to the feedback signal, a second angle of arrival of the receiving device to the eavesdropping device;

12) determining, according to the first angle of arrival and the second angle of arrival, a third angle of arrival of the transmitting device to the receiving device;

13) adjusting a receive beam weight of the first beamformer of the eavesdropping device according to the third angle of arrival.

In this optional implementation, the eavesdropping device may determine a first angle of arrival of each of the transmitting end devices to the eavesdropping device according to the first signal, and the eavesdropping device may further determine, according to the feedback signal, The second angle of arrival of the receiving device to the eavesdropping device, further, the eavesdropping device may determine the transmitting device to the receiving device according to the first angle of arrival and the second angle of arrival a third angle of arrival, and adjusting a receive beam weight of the first beamformer of the eavesdropping device according to the third angle of arrival, such that the eavesdropping device can use the first beamformer of the eavesdropping device The receiving beam is aligned with the direction of the transmitting end device to the receiving end device, so that the eavesdropping capacity of the eavesdropping device can be increased, thereby making the distributed secure communication system The detection of security is more effective.

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

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

Where w ₂ ∈ □ ^{M × 1} represents the weight vector on the second stage listener E.

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

The eavesdropping device determines, according to the feedback signal, that the second SINR of the eavesdropping device can be expressed as:

Referring to FIG. 4, FIG. 5 and FIG. 6, FIG. 4 is a schematic diagram of convergence of an artificial noise signal under different estimation errors according to an embodiment of the present invention; FIG. 5 is a distribution disclosed in an embodiment of the present invention; A schematic diagram of the convergence of the security capacity of the secure communication system; FIG. 6 is a schematic diagram of the convergence of the security capacity of another distributed secure communication system disclosed in the embodiment of the present invention. As shown in FIG. 4 and FIG. 5, the received signal strength (RSS) of the artificial noise signal received by the eavesdropping device is different under different estimation errors, and the eavesdropping device is configured to the transmitting device. When the estimation error of the null angle of the first artificial noise signal is different in the nth time slot, the safety capacity of the distributed safety communication system is different, and the larger the estimation error is, the larger the RSS is, and the easier it is to interfere with the channel direction of the eavesdropping device. The accuracy of the estimation of the information, the greater the security capacity of the distributed secure communication system, that is, the higher the security of the distributed secure communication system. As shown in Figure 6, the number of antennas installed on the eavesdropping device is different, the security capacity of the distributed secure communication system is different, and the more installed antennas, the lower the security capacity of the distributed secure communication system, that is, the distributed secure communication system. The lower the security, the fewer the installed antennas, the higher the security capacity of the distributed secure communication system, ie the higher the security of the distributed secure communication system.

In the method described in FIG. 3, the eavesdropping device can determine each according to the first signal Transmitting the device to the first angle of arrival of the eavesdropping device, and establishing a first beamformer for the first signal, and further, the eavesdropping device may further receive the receiving end according to the monitored nth slot Determining, by the device, a feedback signal sent by the plurality of the transmitting end devices, determining a second SINR of the eavesdropping device; and establishing a second beamformer for the feedback signal.

Please refer to FIG. 7. FIG. 7 is a schematic structural diagram of a security detecting apparatus according to an embodiment of the present invention. The security detection device described in FIG. 7 may be used to perform some or all of the steps in the security detection method of the distributed secure communication system described in FIG. 2 or FIG. 3 . For details, refer to FIG. 2 or FIG. 3 . Related descriptions are not described here. As shown in FIG. 7, the security detecting apparatus may include:

The monitoring unit 701 is configured to monitor, by the nth time slot, a first signal sent by the multiple transmitting end devices to the receiving end device, where the first signal includes a first artificial noise signal, where the nth time slot For the current time slot, the n is a positive integer;

The determining unit 702 is configured to determine, according to the first signal, a first signal to interference and noise ratio SINR of the eavesdropping device;

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

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

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

The security detecting apparatus described in FIG. 7 can implement the security of the distributed secure communication system by detecting the change trend of the security capacity of the receiving end device determined by the eavesdropping device.

Please refer to FIG. 8. FIG. 8 is a schematic structural diagram of another security detecting apparatus according to an embodiment of the present invention. The security detecting apparatus described in FIG. 8 may be used to perform some or all of the steps in the security detecting method of the distributed secure communication system described in FIG. 2 or FIG. Referring to the related description in FIG. 2 or FIG. 3, details are not described herein again. Wherein, the security detecting device described in FIG. 8 is further optimized based on the security detecting device described in FIG. 7, compared with the security detecting device described in FIG.

The determining unit 702 is further configured to determine, according to the first signal, a first angle of arrival of each of the transmitting end devices to the eavesdropping device, to estimate the transmitting end device to the receiving end device Direction angle

The security detecting apparatus described in FIG. 8 further includes:

The establishing unit 704 is configured to establish a first beamformer for the first signal.

The monitoring unit 701 is further configured to monitor a feedback signal sent by the receiving end device to the 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, according to the feedback signal, a second SINR of the eavesdropping device.

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

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

The security detecting device further includes:

The adjusting unit 705 is configured to adjust a receive beam weight of the first beamformer of the eavesdropping 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。The first eavesdropping capacity depends on the estimation error of the eavesdropping device transmitting the null angle of the first artificial noise signal to the nth time slot of the transmitting end device, and the estimated error obeys a mean value of 0. Variance is

Normal distribution, where

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

The antenna is installed on the eavesdropping device, and the plurality of antennas are configured to receive the first signal or the feedback signal.

Wherein, the security detecting apparatus described in FIG. 8 can implement the change trend of the security capacity of the receiving end device determined by the eavesdropping end device, and the distributed secure communication system Security is tested.

In the above embodiments, the descriptions of the various embodiments are different, and the details that are not detailed in a certain embodiment can be referred to the related descriptions of other embodiments.

In the several embodiments provided herein, it should be understood that the disclosed apparatus may be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or may be Integrate into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be electrical or otherwise.

The units described as separate components may or may not be physically separated, and the 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 of the 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 separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable memory. Based on such understanding, the technical solution of the present invention may contribute to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a memory. A number of instructions are included to cause a computer device (which may be a personal computer, server or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing memory includes: a U disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic disk, or an optical disk, and the like, which can store program codes.

One of ordinary skill in the art can understand all or part of the various methods of the above embodiments. The program can be completed by a program to instruct the related hardware, the program can be stored in a computer readable memory, the memory can include: a flash disk, a read-only memory (English: Read-Only Memory, abbreviation: ROM), random memory Take (English: Random Access Memory, referred to as: RAM), disk or CD.

The method and device for detecting security of a distributed secure communication system disclosed in the embodiments of the present invention are described in detail. The principles and implementation manners of the present invention are described in the specific examples. The description of the above embodiments is only The method for understanding the present invention and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in specific embodiments and application scopes. The description should not be construed as limiting the invention.

Claims (10)

A security detection method for a distributed secure communication system is characterized in that it is applied to a eavesdropping device included in a distributed secure communication system, and the distributed secure beamforming system further includes a plurality of transmitting end devices and receiving end devices. The method includes: Listening to the first signal sent by the multiple transmitting end devices to the receiving end device in the nth time slot, where the first signal includes a first artificial noise signal, where the nth time slot is a current time slot, Said n is a positive integer; Determining, according to the first signal, a first signal to interference and noise ratio SINR of the eavesdropping device; Determining, according to the first SINR, a first eavesdropping capacity of the nth time slot of the eavesdropping device; Determining a security capacity of the receiving end device according to the first eavesdropping capacity and the received receiving capacity of the receiving end device; The security of the distributed secure communication system is detected according to the changing trend of the security capacity. The method of claim 1 further comprising: Determining, according to the first signal, a first angle of arrival of each of the transmitting end devices to the eavesdropping device to estimate a direction angle of the transmitting end device to the receiving end device; A first beamformer is established for the first signal. The method of claim 2, wherein the method further comprises: Monitoring a feedback signal sent by the receiving end device to the plurality of the transmitting end devices in the nth time slot; Establishing a second beamformer for the feedback signal; Determining, according to the feedback signal, a second SINR of the eavesdropping device. The method of claim 3, wherein the method further comprises: Determining, according to the feedback signal, a second angle of arrival of the receiving device to the eavesdropping device; Determining, according to the first angle of arrival and the second angle of arrival, a third angle of arrival of the transmitting device to the receiving device; And adjusting a receive beam weight of the first beamformer of the eavesdropping device according to the third angle of arrival. The method according to claim 3, wherein the first eavesdropping capacity is determined by an estimation of a nulling angle of the first artificial noise signal sent by the eavesdropping device to the nth time slot of the transmitting end device. Error, the estimated error obeys a mean of 0, and the variance is

Normal distribution, 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 5, wherein a plurality of antennas are mounted on the eavesdropping device, and the plurality of antennas are configured to receive the first signal or the feedback signal. A security detecting device, characterized in that the eavesdropping device included in the distributed secure communication system comprises: a monitoring unit, configured to monitor a first signal sent by the multiple transmitting end devices to the receiving end device in an nth time slot, where the first signal includes a first artificial noise signal, where the nth time slot is The current time slot, the n is a positive integer; a determining unit, configured to determine, according to the first signal, a first signal to interference and noise ratio SINR of the eavesdropping device; 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 device; The determining unit is further configured to determine a security capacity of the receiving end device according to the first eavesdropping capacity and the received receiving capacity of the receiving end device; And a detecting unit, configured to detect the security of the distributed secure communication system according to the changing trend of the security capacity. The security detecting apparatus according to claim 7, wherein the determining unit is further configured to determine, according to the first signal, a first angle of arrival of each of the transmitting end devices to the eavesdropping device, Estimating a direction angle of the transmitting end device to the receiving end device; The security detecting device further includes: And a establishing unit, configured to establish a first beamformer for the first signal. The security detecting apparatus according to claim 8, wherein the monitoring unit is further configured to monitor a feedback signal sent by the receiving end device to the plurality of 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, according to the feedback signal, a second SINR of the eavesdropping device. The security detecting apparatus according to claim 9, wherein the determining unit is further configured to determine, according to the feedback signal, a second angle of arrival of the receiving device to the eavesdropping device; The determining unit is further configured to determine, according to the first angle of arrival and the second angle of arrival, a third angle of arrival of the transmitting device to the receiving device; The security detecting device further includes: And an adjusting unit, configured to adjust a received beam weight of the first beamformer of the eavesdropping device according to the third angle of arrival.

Images