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作者： Amaro Barreal Fernandez Aalto University

学位级别：博士

Lattices are deceptively simple mathematical structures that have become indispensable for code design for physical layer communications. While lattice-related problems are interesting in their own right, the usefulness of these discrete structures in wireless communications provides additional motivation for their study and enables a multidisciplinary line of research. This thesis is devoted to the study of lattice code design for physical layer communications. Modern wireless communication networks are required to accommodate significantly varied types of mobile devices, differing in available computational power or number of equipped antennas. Additionally, the density of the networks increases rapidly, and many communication protocols diverge from the classical direct point-to-point transmission in favor of allowing for intermediate relays to process and forward data. An important consequence of this shift towards more sophisticated transmission protocols is that traditional well-performing codes become futile for modern communications, thus the study and development of novel codes is called for. Yet, however involved a transmission protocol may be, the characteristics of the physical medium, i. e., the wireless channel, stay unaffected. It is thus natural that an underlying lattice structure for code design remains crucial. This thesis consists of several articles considering lattice code design for four different communication settings relevant in modern wireless communications. We begin by studying two communication scenarios for which space-time lattice codes, objects studied since 1998, arise naturally due to the characteristics of the transmission protocol. The first considered setup is an asymmetric point-to-point channel, for which we construct full-rank matrix lattices which serve as the underlying structure for code construction. In particular, we are interested in an invariant of certain orders in the considered algebra, called discriminant. We then m

关键词： Lattices physical layer network coding Space--Time Codes Nested Lattice Codes Wireless Communications

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Design of Two Way Relay network Using Space-Time Block Coded network coding and Linear Detection

Design of Two Way Relay Network Using Space-Time Block Coded...

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IEEE 79th Vehicular Technology Conference (VTC-Spring)

作者： Duc Hiep Vu Van Bien Pham Xuan Nam Tran Chi Hieu Ta Le Quy Don Tech Univ Cau Giay Ha Noi Vietnam

ISBN: (纸本)9781479944828

This paper presents a design of two-way two-hop relay network using physical layer network coding (PNC) in which multiple antennas are used at all nodes. For transmission over the multiple-input multiple-output channels, the Alamouti's space-time block code (STBC) is used for transmission while linear detection is used for signal estimation at all nodes. In order to facilitate linear detection, we develop an equivalent multiuser STBC model for the proposed network and design the sum-and-difference matrix which is suitable for signal estimation. Simulation results show that the proposed network achieves diversity order 2 with polynomial complexity.

关键词： MIMO communication antenna arrays computational complexity matrix algebra network coding relay networks (telecommunication) signal processing space-time block codes Alamouti space-time block code MIMO channels PNC diversity order 2 equivalent multiuser STBC model linear detection multiple antennas multiple-input multiple-output channels physical layer network coding polynomial complexity signal estimation sum-and-difference matrix two-way two-hop relay network design Antennas Estimation MIMO network coding Relay networks (telecommunications) Vectors linear detection network coding Signal estimation space time block coding multiple antenna PNC MIMO communication matrix algebra Antenna arrays multiple input multiple output systems ANTENNA signal processing complexity classes Relay networks

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network-coded diversity protocol for collision recovery in slotted ALOHA networks

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INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND networkING 2014年第3期32卷 225-241页

作者： Cocco, G. Alagha, N. Ibars, C. Cioni, S. CTTC Castelldefels 08860 Spain European Space Agcy Estec NL-2200 AG Noordwijk Netherlands

We propose a collision recovery scheme for symbol-synchronous slotted ALOHA based on physical layer network coding over extended Galois fields. Information is extracted from colliding bursts allowing to achieve higher maximum throughput with respect to previously proposed collision recovery schemes. An energy efficiency analysis is also performed, and it is shown that by adjusting the transmission probability, high energy efficiency can be achieved. A performance evaluation is carried out using the proposed algorithms, revealing remarkable performance in terms of normalized throughput. Copyright (C) 2013 John Wiley & Sons, Ltd.

关键词： multiple access MAC physical layer network coding PNC slotted ALOHA collision resolution

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Wiretap resisting and privacy preserving data exchange with physical layer security and blockchain based authentication in Internet of Vehicles

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MICROPROCESSORS AND MICROSYSTEMS 2024年 104卷

作者： Liu, Qiao Han, Qi Luo, Guangze Cao, Jin Li, Hui Wang, Yong Xidian Univ Sch Cyber Engn Xian Shaanxi Peoples R China Xidian Univ State Key Lab ISN Xian Shaanxi Peoples R China Xian Inst Appl Opt Xian Peoples R China

With the development of automobile industry technology, vehicles have greatly affected everyday life, work and other aspects. With the continuous innovation of sensor technology, computer technology, wireless communication technology, and GPS technology, the concept of Inter of Vehicles (IoV) has been widely regarded as the core technology to solve a series of problems. However, as a complexity network with multiple elements including people, vehicle, base-station and so on, IoV is confronted with security threatened. In this paper, secure data exchange has been considered for two authenticated On Board Units (OBUs) with help of Road Side Unit (RSU). Blockchain based authentication and physical layer security have been applied into IoV for wiretap resisting and privacy preserving data exchange. For wiretap resisting, two synchronized transmitted signals from OBUs act as artificial noise at eavesdropper. In addition, for privacy preserving, summed codeword is formed at RSU which cannot be recovered individually. Finally, simulation results have been conducted to demonstrate that the proposed protocol can achieve transmission efficiency as well as informatics security.

关键词： Vehicle to Vehicle Blockchain based authentication physical layer network coding Wiretap resisting Privacy preserving

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Improving the security of NOMA cognitive networks

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physical COMMUNICATION 2024年 67卷

作者： Li, Enyu Zheng, Meijuan Liang, Zanyang Wang, Ye Wang, Haoming Qingdao Univ Technol Sch Informat & Control Engn Qingdao 266520 Peoples R China

Aiming at the scenario where the eavesdropper try to eavesdrop on the confidential messages of secondary trusted users, two physical-layer network coding (PNC) strategies, namely dual power superposition (PS-PS) encoding strategy and bit-level exclusive-or power superposition (XOR-PS) encoding strategy, are proposed to improve the security performance of cognitive non-orthogonal multiple access (NOMA) networks with the help of the data transmitted by the primary user. Considering the overlay spectrum sharing mechanism and the imperfect successive interference cancellation (SIC) technology, we first derive the closed-form accurate expressions of the outage probability and intercept probability of the secondary network with these two schemes over Rayleigh fading, and also give the asymptotic outage probability in the high signal-to-noise ratio (SNR) regime. Then, the correctness of the theoretical results is verified by simulation. For comparison, we also use the scheme without the assistance of the primary user as the benchmark scheme, which is represented by NPS. Finally, the simulation results show that the security of the proposed PS-PS and XOR-PS schemes is much better than that of the NPS scheme in the case of without reducing the outage performance.

关键词： Non-orthogonal multiple access Successive interference cancellation physical layer network coding Bit-level XOR Outage probability Intercept probability

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Backscatter Assisted NOMA-PLNC Based Wireless networks

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SENSORS 2021年第22期21卷 7589页

作者： Rajkumar, Samikkannu Jayakody, Dushantha Nalin K. Sch Engn Ctr Telecommunicat Res Sri Lanka Technological Campus Padukka 10500 Sri Lanka Natl Res Tomsk Polytechn Univ Sch Comp Sci & Robot Tomsk 634050 Russia

In this paper, sum capacity maximization of the non-orthogonal multiple access (NOMA)-based wireless network is studied in the presence of ambient backscattering (ABS). Assuming that ABS is located next to far nodes, it improves the signal strength of far node cluster. By applying suitable successive interference cancellation (SIC) operation, far node cluster act as an internet of things (IoT) reader. Moreover, to improve the uplink performance of the nodes, a physical layer network coding (PLNC) scheme is applied in the proposed network. Power optimization is employed at the access point (AP) to enhance the downlink performance with total transmit power constraint and minimum data rate requirement per user constraint using Lagrangian's function. In addition, end-to-end outage performance of the proposed wireless network is analyzed to enhance each wireless link capacity. Numerical results evident that the outage performance of the proposed network is significantly improved while using the ABS. Furthermore, the average bit error rate (BER) performance of the proposed wireless network is studied to improve the reliability. Simulation results are presented to validate the analytical expressions.

关键词： non-orthogonal multiple access physical layer network coding ambient backscattering

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BER Analysis of mmWave Bidirectional Relay network

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JOURNAL OF INFORMATION SCIENCE AND ENGINEERING 2018年第2期34卷 435-450页

作者： Murugavalli, E. Thiruvengadam, S. J. Thiagarajar Coll Engn Dept Elect & Commun Engn TIFAC CORE Wireless Technol Madurai 625015 Tamil Nadu India

Millimeter-wave (mmWave) communication is one of the emerging key components for next generation wireless networks. It exploits unlicensed band at 60 GHz in an indoor environment. Since the wave propagation at mmWave frequencies exhibits a quasi-optical behaviour, the inherent line of sight (LoS) channel models provide new research directions. The major challenges in mmWave communication are higher free space path loss (FSPL) due to its smaller wavelength, quasi-optical behaviour of wave propagation and blockage and penetration losses in indoor scenario. The losses can be compensated using multiple antenna (MA) systems and the sparse channel behaviour of mmWave propagation is compensated by optimal and aligned antenna geometry. However, MA system increases hardware constraints as the number of radio frequency (RF) chains increases. In the recent years, space shift keying (SSK) modulation scheme has been identified as a promising MA technique with single RF hardware requirement. In SSK, only one antenna is activated for transmission at any time instant and the index of this active antenna is used to convey information. Reliable communication between the nodes in a network can be established with the aid of relay node in mmWave communication. In this paper, a bidirectional relay network model using mmWave communication in indoor-LoS environment is considered. The concept of physical layer network coding (PLNC) is applied at the decode-and-forward (DF) relay node to enable the network operates in bidirectional half duplex mode. Specifically, the transceiver at the nodes sends the information symbol by employing SSK modulation and detects the symbol based on the maximum likelihood (ML) detection criterion. By considering optimal antenna geometry operating conditions in LoS environment, the end-to-end bit error rate (BER) probability of the proposed PLNC based bidirectional relay network using SSK in mmWave communication is derived in closed form. Analytical frameworks a

关键词： bidirectional relay network physical layer network coding bit error probability indoor LoS space shift keying mmWave communications

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Hierarchical Data Decision Aided 2-Source BPSK H-MAC Channel Phase Estimator with Feed-Back Gradient Solver for WPNC networks and Its Equivalent Model

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INFORMATION 2019年第2期10卷

作者： Sykora, Jan Czech Tech Univ Dept Radio Engn Prague 16627 6 Czech Republic

This paper focuses on the channel state estimation (CSE) problem in parametrized Hierarchical MAC (H-MAC) stage in Wireless physical layer network coding (WPNC) networks with Hierarchical Decode and Forward (HDF) relay strategy. We derive a non-pilot based H-MAC channel phase estimator for 2 BPSK alphabet sources. The CSE is aided only by the knowledge of H-data decisions. At HDF relay, there is no information on individual source symbols available. The estimator is obtained by a marginalization over the hierarchical dispersion. The estimator uses a gradient additive update solver and the indicator function (gradient) is derived in exact closed form and in approximations for low and high SNR. We analyze the properties of the equivalent solver model, particularly the equivalent gradient detector characteristics and its main stable domain properties, and also the detector gain and equivalent noise properties under a variety of channel parameterization scenarios.

关键词： physical layer network coding phase estimation feed-back solver

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Multiple Packet Reception in Asynchronous Wireless networks

Multiple Packet Reception in Asynchronous Wireless Networks

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International Conference on Computing, networking and Communications (ICNC)

作者： Argyriou, Antonios Univ Thessaly Dept Comp & Commun Engn Volos 38221 Greece

ISBN: (纸本)9781467300094;9781467352871

In this paper we present a scheme for multiple-packet reception (MPR) that allows the concurrent packet transmission from several asynchronous users and is based on a new algorithm for successive interference cancellation (SIC). Transmitted signals are superimposed at the destination nodes and also at a relay node. The system model allows for the transmitted packets to be superimposed asynchronously with an arbitrary pattern at each node that receives them. For the final version of the proposed scheme we present a joint MPR and channel decoding algorithm.

关键词： Wireless networks cooperative systems multiple packet reception physical layer network coding successive interference cancelation

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Ergodic Rate Analysis of Power Allocation Schemes in Two-way Decode-and-Forward Relay Systems

Ergodic Rate Analysis of Power Allocation Schemes in Two-way...

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IEEE Vehicular Technology Conference

作者： Chen Chen Yehua Yang Lin Bai Ye Jin Jinho Choi State Key Laboratory of Advanced Optical Communication Systems and Networks Peking University Beijing China School of Electronic and Information Engineering Beihang University Beijing China School of Information and Communications Gwangju Institute of Science and Technology (GIST) Korea

ISBN: (纸本)9781479980925

Most previous researches on the rate analysis of the power allocation (PA) schemes in two-way decode-and-forward (DF) relay systems typically focus on maximizing the instantaneous objective rates. However, the ergodic rate analysis of the optimized rates is not well considered. In this paper, we investigate the ergodic rates of the PA schemes in a two-way DF relay system, where the physical-layer network coding (PNC) protocol is adopted. Specifically, under a total power constraint, we consider three heuristic PA schemes, in which the optimization objectives are: 1) maximizing the sum rate;2) maximizing the sum rate with an additional rate fairness constraint;and 3) maximizing the minor rate of the two directions of the system. The cumulative distribution functions (CDFs) of the equivalent system SNR are approximately obtained and the analytical expressions for the calculations of the ergodic rates are theoretically derived. Numerical results show that the derived analytical rates are converged to the simulated results in high SNR regions.

关键词： Two-way relay system physical layer network coding power allocation ergodic rate power splitting Relay systems Bidirectional Nylons Scheme

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