KR20190003087A - Method for improving secrecy performance of full-duplex relay system with randomly located eavesdroppers - Google Patents

Abstract

The present invention relates to a method to improve security performance of a full-duplex relay system including a plurality of randomly located eavesdroppers, capable of increasing efficiency of a frequency. According to the present invention, when the randomly located eavesdroppers exist in the full-duplex relay system, a transmitter (source, S) and a receiver (destination, D) perform communication through a full-duplex relay (R) using a decode-and-forward scheme.

Description

METHOD FOR IMPROVING SECURITY PERFORMANCE OF FULL-DUPLEX RELAY SYSTEM WITH RANDOMLY LOCATED EAVESDROPPERS FIELD OF THE INVENTION [0001]

The present invention relates to a method for enhancing security performance using a full duplex relay method when a randomly located multiple eavesdropping eavesdrop on a signal sent by a transmitter, and is related to physical layer security of communication.

A full - duplex relay system is a relay system in which a repeater receives a signal transmitted from a transmitter and transmits a signal to a receiver, and can improve the transmission rate by using resources more efficiently than a half - duplex relay system. Randomly located multiple eavesdroppers are not positioned, but rather randomly located eavesdroppers according to the Poisson Point Process.

[1] proposed a half-duplex relay system in which a transmitter and a receiver communicate via a half-duplex repeater using a post-decode transmission technique when there are multiple randomly located eavesdroppers. In this system, the repeater operates in a half-duplex manner, so the transmitter sends information to the receiver in two hops, which makes it inefficient to use the resources, and the eavesdropper is easy to eavesdrop because it receives signals from one of the receiver and the repeater.

[1] C. Liu, N. Yang, R. Malaney, and J. Yuan, "Artificial-noise-aided transmission in multi-antenna relay wiretap channels with spatially random eavesdroppers," IEEE Trans. Wireless Commun., Vol. 15, no. 11, pp. 7444-7456, Nov. 2016.

The above-described background technology is technical information that the inventor holds for the derivation of the present invention or acquired in the process of deriving the present invention, and can not necessarily be a known technology disclosed to the general public prior to the filing of the present invention.

The present invention proposes a full-duplex relay system in which a transmitter and a receiver communicate via a full-duplex repeater using a post-decode transmission technique when there are multiple randomly located eavesdroppers.

One embodiment of the present invention provides a method for enhancing the security performance of a full-duplex relay system in which multiple eavesdroppers are located at random.

According to the present invention, the full-duplex relay system has an advantage that the frequency efficiency is higher than that of the half-duplex relay system, and simultaneous signal transmission between the transmitter and the repeater hinders eavesdropping of the eavesdropper.

1 is a diagram illustrating a full duplex relay system in the presence of a plurality of eavesdroppers according to an embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. The effects and features of the present invention and methods of achieving them will be apparent with reference to the embodiments described in detail below with reference to the drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

However, the present invention is not limited to the embodiments described below, but all or some of the embodiments may be selectively combined and implemented in various forms. In the following embodiments, the terms first, second, and the like are used for the purpose of distinguishing one element from another element, not the limitative meaning. Also, the singular expressions include plural expressions unless the context clearly dictates otherwise. Also, the terms include, including, etc. mean that there is a feature, or element, recited in the specification and does not preclude the possibility that one or more other features or components may be added.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or corresponding parts throughout the several views, and redundant description thereof will be omitted.

1 is a diagram illustrating a full duplex relay system in the presence of a plurality of eavesdroppers according to an embodiment of the present invention.

의 밀도를 가지는 homogeneous Poisson Point Process

를 따라 공간적으로 위치해 있다고 가정한다. 전이중 중계기는 두개의 안테나를 가지고 있어 각각 송신과 수신하는데 사용하며, 다른 기기들은 단일 안테나를 가지고 있다고 가정한다.In the present invention, a transmitter (source S) and a receiver (destination D) communicate with each other via a full-duplex relay (R) using a transmission technique after decryption when a randomly located multiple eavesdroppers We propose a full duplex relay system. It is assumed that the transmitter, the repeater, and the receiver are in a fixed position and there is no direct path between the transceivers. Many eavesdroppers

Homogeneous Poisson Point Process

As shown in FIG. A full-duplex repeater has two antennas, one for transmitting and receiving, and the other for receiving a single antenna.

Communication is done in block units. In each block, the transmitter transmits the signal to the repeater while the repeater transmits the signal to the receiver. At this time, the repeater receives not only the signal transmitted from the transmitter but also a self-interference signal transmitted by itself. The repeater decodes the received signal, re-encodes it, and transmits it to the receiver in the next block.

Many eavesdroppers assume that they hear the signals transmitted by the transmitter and the repeater. The transmitter and the repeater use different code books to assume that the eavesdropper must separately decode the signal received from the first hop (S-R) and the second hop (R-D). Also, many eavesdroppers assume that they do not cooperate with each other and decode information only with the signal they receive.

라고 표기하며 각 채널은 평균이 0이고 분산이

인 가산 백색 가우시안 잡음을 가진다고 가정한다. 기기 i와 j 사이의 거리를

라고 표기하며 기기 i의 전송 전력을

라고 표기한다. 자기 간섭 제거(self-interference cancellation) 후에 남은 자기 간섭의 비율을

라고 표기한다.It is assumed that the channel is constant for one block and changes in block units. The channel coefficients between devices i and j in the kth block

Each channel has an average of 0 and variance

Is assumed to have additive white Gaussian noise. The distance between devices i and j is

And the transmission power of the device i

. The ratio of the remaining magnetic interference after self-interference cancellation

.

In the kth block, the signal-to-interference-plus-noise ratios (SINRs) of the repeater and one eavesdropper are as follows.

[Equation 1]

&Quot; (2) "

The signal-to-noise ratio of the receiver and the eavesdropper e in the k + 1th block is as follows.

&Quot; (3) "

&Quot; (4) "

The end-to-end signal-to-noise-and-noise-and-noise ratio between the transceivers when relayed to the transmission system after decoding is as follows.

&Quot; (5) "

When the transmitter and the repeater use different code locks, the signal-to-noise interference ratio of the eavesdropper e is as follows.

&Quot; (6) "

When multiple eavesdroppers are non-colluding, the system's secrecy rate is determined by the most detrimental eavesdropper. Here, the most harmful eavesdropper means the eavesdropper with the largest signal-to-interference noise ratio, and the worst eavesdropper's signal-to-noise interference ratio is

&Quot; (7) "

The security transfer rate of the system is as follows.

&Quot; (8) "

는 0과

중에 큰 값을 반환하는 함수이다. 이 때, 시스템의 보안불능확률(secrecy outage probability)과 평균보안전송률(average secrecy rate)는 다음과 같다.here

0 and

Is a function that returns a large value. In this case, the secrecy outage probability and the average secrecy rate of the system are as follows.

&Quot; (9) "

&Quot; (10) "

The present invention is applicable to a system for transmitting important information through a repeater in an environment where a plurality of eavesdroppers are likely to be eavesdropped and there is no direct path between the transceivers. It can be used especially when communicating security-critical information in military situations or communicating in areas where users can hear information.

The specific acts described in the present invention are, by way of example, not intended to limit the scope of the invention in any way. For brevity of description, descriptions of conventional electronic configurations, control systems, software, and other functional aspects of such systems may be omitted. Also, the connections or connecting members of the lines between the components shown in the figures are illustrative of functional connections and / or physical or circuit connections, which may be replaced or additionally provided by a variety of functional connections, physical Connection, or circuit connections. Also, unless explicitly mentioned, such as " essential ", " importantly ", etc., it may not be a necessary component for application of the present invention.

Accordingly, the spirit of the present invention should not be construed as being limited to the above-described embodiments, and all ranges that are equivalent to or equivalent to the claims of the present invention as well as the claims .

Claims (1)

A method for improving the security performance of a full-duplex relay system in which multiple randomly located eavesdroppers are present.

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