Biblio

A wireless communication system with rotating linearly polarized antennas is built and tested as a method for increasing physical layer security. Controlling the linear polarization angle from 0° to 180° yields bit error rates greater than 20% for 40° of rotation.

In order to solve the problem of data analysis and application caused by the inefficient integration of hardware and software compatibility of hardware in the Internet of things, this paper proposes and designs a C/S framework communication system based on task driven and multi-user authority. By redefining the relationship between users and hardware and adopting the matching framework for different modules, the system realizes the high concurrent and complex data efficient collaborative processing between software and hardware. Finally, by testing and verifying the functions of the system, the communication system effectively realizes the functions of data processing between software and hardware, and achieves the expected results.

This paper designs a re-transmission strategy to intensify the security of communication over the additive white Gaussian noise (AWGN) wire-tap channel. In this scheme, irregular low-density parity-check (LDPC) codes work with reliability-based hybrid automatic repeat-request (RB-HARQ). For irregular LDPC codes, the variable nodes have different degrees, which means miscellaneous protection for the nodes. In RB-HARQ protocol, the legitimate receiver calls for re-transmissions including the most unreliable bits at decoder's outputting. The bits' reliability can be evaluated by the average magnitude of a posteriori probability log-likelihood ratios (APP LLRs). Specifically, this scheme utilizes the bit-error rate (BER) to assess the secrecy performance. Besides, the paper gives close analyses of BER through theoretical arguments and simulations. Results of numerical example demonstrate that RB-HARQ protocol with irregular LDPC codes can hugely reinforce the security performance of the communication system.

With the deep research on coherent optical OFDM offset quadrature amplitude modulation OFDM/OQAM in these years, and the communication system exposed to potential threat from various capable attackers, which prompt people lay emphasis on encryption methods for transmission. Therefore, in this paper, we systematically discuss an encryption project with the main purpose of improving security in coherent optical OFDM/OQAM (CO-OFDM/OQAM) system, and the scheme applied the chaotic constellation scrambling (CCS) which founded on chaotic cross mapping to encrypt transmitted information. Besides, we also systematically discuss the basic principle of the encryption scheme for CO-OFDM/OQAM system. According to numerous studies and analysis on experiment data with caution, such as the performance of entropy, bit error rate (BER). It's conforms that the security of CO-OFDM/OQAM system have been enhanced.

With the advancement in technology, inclusion of Information and Communication Technology (ICT) in the conventional Electrical Power Grid has become evident. The combination of communication system with physical system makes it cyber-physical system (CPS). Though the advantages of this improvement in technology are numerous, there exist certain issues with the system. Security and privacy concerns of a CPS are a major field and research and the insight of which is content of this paper.

In recent years, the demand for high reliability in industrial wireless communication has been increasing. To meet the strict requirement, many researchers have studied various bit interleaving coding schemes for long packet transmission in industrial wireless networks. Current research shows that the use of bit interleaving structure can improve the performance of the communication system for long packet transmission, but to improve reliability of industrial wireless communications by combining the bit interleaving and channel coding for short packets still requires further analysis. With this aim, bit interleaving structure is applied to convolution code coding scheme for short packet transmission in this paper. We prove that the use of interleaver fail to improve the reliability of data transmission under the circumstance of short packet transmission.

Fully connected autonomous vehicles are more vulnerable than ever to hacking and data theft. The controller area network (CAN) protocol is used for communication between in-vehicle control networks (IVN). The absence of basic security features of this protocol, like message authentication, makes it quite vulnerable to a wide range of attacks including spoofing attacks. As traditional cybersecurity methods impose limitations in ensuring confidentiality and integrity of transmitted messages via CAN, a new technique has emerged among others to approve its reliability in fully authenticating the CAN messages. At the physical layer of the communication system, the method of fingerprinting the messages is implemented to link the received signal to the transmitting electronic control unit (ECU). This paper introduces a new method to implement the security of modern electric vehicles. The lumped element model is used to characterize the channel-specific step response. ECU and channel imperfections lead to a unique transfer function for each transmitter. Due to the unique transfer function, the step response for each transmitter is unique. In this paper, we use control system parameters as a feature-set, afterward, a neural network is used transmitting node identification for message authentication. A dataset collected from a CAN network with eight-channel lengths and eight ECUs to evaluate the performance of the suggested method. Detection results show that the proposed method achieves an accuracy of 97.4% of transmitter detection.

Optical CDMA (OCMDA) technology directly encrypts optical transmission links at the physical layer, which can improve the security of communication system against fibre-optic eavesdropping attacks. System parameters will affect the performances of OCDMA systems, based on the wiretap channel model of OCDMA systems, "secrecy capacity" is employed as an indicator to estimate the effects of system parameters (the type of code words, the length of code words) on the security of the systems. Simulation results demonstrate that system parameters play an important role and choosing the code words with better cross-correlation characteristics can improve the security of OCDMA systems.

Images acquired and processed in communication and multimedia systems are often noisy. Thus, pre-filtering is a typical stage to remove noise. At this stage, a special attention has to be paid to image visual quality. This paper analyzes denoising efficiency from the viewpoint of visual quality improvement using metrics that take into account human vision system (HVS). Specific features of the paper consist in, first, considering filters based on discrete cosine transform (DCT) and, second, analyzing the filter performance locally. Such an analysis is possible due to the structure and peculiarities of the metric PSNR-HVS-M. It is shown that a more advanced DCT-based filter BM3D outperforms a simpler (and faster) conventional DCT-based filter in locally active regions, i.e., neighborhoods of edges and small-sized objects. This conclusions allows accelerating BM3D filter and can be used in further improvement of the analyzed denoising techniques.

Turbo code has been one of the important subjects in coding theory since 1993. This code has low Bit Error Rate (BER) but decoding complexity and delay are big challenges. On the other hand, considering the complexity and delay of separate blocks for coding and encryption, if these processes are combined, the security and reliability of communication system are guaranteed. In this paper a secure decoding algorithm in parallel on General-Purpose Graphics Processing Units (GPGPU) is proposed. This is the first prototype of a fast and parallel Joint Channel-Security Coding (JCSC) system. Despite of encryption process, this algorithm maintains desired BER and increases decoding speed. We considered several techniques for parallelism: (1) distribute decoding load of a code word between multiple cores, (2) simultaneous decoding of several code words, (3) using protection techniques to prevent performance degradation. We also propose two kinds of optimizations to increase the decoding speed: (1) memory access improvement, (2) the use of new GPU properties such as concurrent kernel execution and advanced atomics to compensate buffering latency.