With the continuous development of the fifth generation (5G) technology, the physical layer of the wireless communication network is facing new challenges. How to effectively prevent and protect these key technologies in the physical layer has a great impact on the entire network and even the entire society. Information security early warning model is a state evaluation model of important security control points in the physical layer of communication network. Security is an important indicator of communication system. Whether its security protection is effective is the basis of its survival and use. Aiming at the situation that the receiver is monitored in the transmission system, this paper has studied the safe transmission method assisted by artificial noise (AN). After the simulation experiment of the physical layer security transmission algorithm, this paper discussed the performance of different algorithms in three scenarios: transmission under non ideal channel information, one-way relay eavesdropping system, and multiple input multiple output (MIMO) untrusted relay eavesdropping system. When analyzing the relationship between the safe transmission rate of different MIMO untrusted relay antennas and the target power constraint $A_{T}, M_{y}=5, M_{d}3, M_{t}=4, A_{t}=\{5,35\}$ dB. On this basis, the optimal power distribution was realized. In the six schemes, when the power constraint $A_{T}$ increased, the security transmission rate of each scheme was improved.
With the continuous development of the fifth generation (5G) technology, the physical layer of the wireless communication network is facing new challenges. How to effectively prevent and protect these key technologies in the physical layer has a great impact on the entire network and even the entire society. Information security early warning model is a state evaluation model of important security control points in the physical layer of communication network. Security is an important indicator of communication system. Whether its security protection is effective is the basis of its survival and use. Aiming at the situation that the receiver is monitored in the transmission system, this paper has studied the safe transmission method assisted by artificial noise (AN). After the simulation experiment of the physical layer security transmission algorithm, this paper discussed the performance of different algorithms in three scenarios: transmission under non ideal channel information, one-way relay eavesdropping system, and multiple input multiple output (MIMO) untrusted relay eavesdropping system. When analyzing the relationship between the safe transmission rate of different MIMO untrusted relay antennas and the target power constraint AT,My=5,Md3,Mt=4,At={5,35} dB. On this basis, the optimal power distribution was realized. In the six schemes, when the power constraint AT increased, the security transmission rate of each scheme was improved.
The open nature of radio propagation enables ubiquitous wireless communication. This allows for seamless data transmission. However, unauthorized users may pose a threat to the security of the data being transmitted to authorized users. This gives rise to network vulnerabilities such as hacking, eavesdropping, and jamming of the transmitted information. Physical layer security (PLS) has been identified as one of the promising security approaches to safeguard the transmission from eavesdroppers in a wireless network. It is an alternative to the computationally demanding and complex cryptographic algorithms and techniques. PLS has continually received exponential research interest owing to the possibility of exploiting the characteristics of the wireless channel. One of the main characteristics includes the random nature of the transmission channel. The aforesaid nature makes it possible for confidential and authentic signal transmission between the sender and the receiver in the physical layer. We start by introducing the basic theories of PLS, including the wiretap channel, information-theoretic security, and a brief discussion of the cryptography security technique. Furthermore, an overview of multiple-input multiple-output (MIMO) communication is provided. The main focus of our review is based on the existing key-less PLS optimization techniques, their limitations, and challenges. The paper also looks into the promising key research areas in addressing these shortfalls. Lastly, a comprehensive overview of some of the recent PLS research in 5G and 6G technologies of wireless communication networks is provided.
The fifth generation (5G) network will serve as a key enabler in meeting the continuously increasing demands for future wireless applications, including an ultra-high data rate, an ultrawide radio coverage, an ultra-large number of devices, and an ultra-low latency. This article examines security, a pivotal issue in the 5G network where wireless transmissions are inherently vulnerable to security breaches. Specifically, we focus on physical layer security, which safeguards data confidentiality by exploiting the intrinsic randomness of the communications medium and reaping the benefits offered by the disruptive technologies to 5G. Among various technologies, the three most promising ones are discussed: heterogenous networks, massive multiple-input multiple-output, and millimeter wave. On the basis of the key principles of each technology, we identify the rich opportunities and the outstanding challenges that security designers must tackle. Such an identification is expected to decisively advance the understanding of future physical layer security.
The fifth generation (5G) network would be a key facilitator to keeping up to the future wireless application demands such as ultra-high data rate, ultra-wide radio coverage, ultra — low latency, large number of devices connected etc. Security is a crucial issue in the 5G network as wireless transmissions have the innate quality of vulnerability towards unfriendly breach or hacks. In this paper, security issue in the 5G network, specifically the physical layer security, has been analyzed. The physical layer safeguards confidentiality of data by capitalizing on the inherent random nature of the communication medium. There are various technologies prevalent in 5G, the three most prominent ones-heterogeneous networks, massive multiple-input multiple-output, and millimeter wave have been considered and discussed. The potential areas for improvement and issues in each of the technologies have been identified and analyzed. This analysis would help in better understanding of physical layer security in the future.
Security has become an increasingly significant and urgent issue in wireless networks. The growing computational capability of the eavesdropper (Eve) and more and more complicated secure key management in large scale and heterogeneous networks, pose more and more stringent requirement to the cryptographic protocols. As a new design paradigm, physical layer security has been recognised as a promising solution to enhance the security of wireless links relying on the channel properties and advanced signal processing, and can act as either an alternative or a complementary solution to the conventional cryptographic methods. Without complicated secure key generation and management, physical layer security is quite suitable for the large scale distributed networks. In this thesis, we aim to improve the secrecy performance in emerging wireless communication systems relying on different physical layer security techniques. Firstly, the security of an amplify-and-forward successive relaying network with multiple untrusted relay nodes is investigated, where the conventional detrimental inter-relay interference is exploited to jam the untrusted nodes without assistance of external helpers. Considering different complexity requirements, several relay selection schemes are proposed, and the closed-form expressions of the lower bound of the secrecy outage probability and the maximum secrecy diversity order are derived accordingly. It is shown that the maximum secrecy diversity order of N-1 can be achieved for an N relay nodes network. Secondly, the artificial noise (AN) aided secure transmission strategy for a multiple-input single-output multiple-Eve (MISOME) system with a secure user (Bob) and a normal user (NU) is investigated. The power allocations among Bob, NU and AN, as well as the wiretap code rates, are jointly optimized to maximize the effective secrecy throughput (EST), under the average throughput constraint of NU. An alternative optimization algorithm with guaranteed convergence is proposed to obtain the optimal parameters. It is shown that the EST increases with the transmitting power and the number of transmit antennas, and decreases with the throughput constraint of NU, and the EST can be improved through injecting AN and concurrent transmission of Bob and NU. Thirdly, physical layer security in a multi-antenna small-cell network is investigated, where the multi-antenna base stations (BSs), cellular users, and Eves are all randomly distributed according to independent Poisson point processes. Stochastic geometry is applied to analyze the connection and secrecy outage probabilities and the average achievable secrecy rate. The impact of different parameters, including power allocation, BS and Eve density, and the adaptive eavesdropping or jamming on the secrecy performance is analyzed. It is shown that the average secrecy rate is a quasi-concave function of the power allocation factor and monotonically decreases with the ratio of the Eve-BS density. Finally, we study the physical layer security in a large-scale heterogeneous network consisting of both sub-6 GHz massive multi-input multi-output (MIMO) macro cells and millimeter wave (mmWave) small cells. By considering pilot spoofing attacks from the Eves, the coverage and secrecy probabilities are derived using stochastic geometry and the conditions under which the millimeter wave tier outperforms the sub-6 GHz counterpart are discussed in terms of both coverage and secrecy.It is shown that the mmWave small cell can provide better coverage performance in the high transmission code-rate region, and the secrecy performance of the mmWave system outperforms the sub-6 GHz counterpart in the low redundant rate region, which reveals the advantage of using mmWave for secure communication.
With the rapid development of mobile Internet technology and the continuous improvement of people's understanding of data security, the research on the secure transmission of information in wireless communication systems has received extensive attention. Using physical layer security technology to protect the information transmission security is not only beneficial to prevent illegal eavesdroppers from obtaining the transmitted information, but also greatly reduces the computational complexity caused by traditional encryption methods. Based on Shannon's communication theory and Wyner's wiretapping channel, this paper briefly introduces the physical layer transmission security technologies such as beamforming, artificial noise and cooperative communication, mainly analyzes massive MIMO antennas and intelligent reflecting surface, and makes a prospect summary. At the end of the paper, the open issues are identified as our future research directions.
Security issue has been considered as one of the most pivotal aspects for the fifth-generation mobile network (5G) due to the increasing demands of security service as well as the growing occurrence of security threat. In this paper, instead of focusing on the security architecture in the upper layer, we investigate the secure transmission for a basic channel model in a heterogeneous network, that is, two-way relay channels. By exploiting the properties of the transmission medium in the physical layer, we propose a novel secure scheme for the aforementioned channel mode. With precoding design, the proposed scheme is able to achieve a high transmission efficiency as well as security. Two different approaches have been introduced: information theoretical approach and physical layer encryption approach. We show that our scheme is secure under three different adversarial models: ( 1 ) untrusted relay attack model, ( 2 ) trusted relay with eavesdropper attack model, and ( 3 ) untrusted relay with eavesdroppers attack model. We also derive the secrecy capacity of the two different approaches under the three attacks. Finally, we conduct three simulations of our proposed scheme. The simulation results agree with the theoretical analysis illustrating that our proposed scheme could achieve a better performance than the existing schemes.