Author: Yunhan ZhangPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Performance Analysis of Relay-aided Wireless Communication Systems
Author: Yunhan ZhangPower Distribution and Performance Analysis for Wireless Communication Networks
Author: Dongmei ZhaoPublisher: Springer Science & Business Media
ISBN: 1461432847
Category : Computers
Languages : en
Pages : 107
Book Description
This book provides an analysis of transmission power and network performance in different wireless communication networks. It presents the latest research and techniques for power and interference control and performance modeling in wireless communication networks with different network topologies, air interfaces, and transmission techniques. While studying the power distributions and resource management, the reader will also learn basic methodology and skills for problem formulations, can ascertain the complexity for designing radio resource management strategies in modern wireless communication networks, thus keeping pace with state-of-the-art research progress in radio transmission technologies.
Amplify-and-Forward Relaying in Wireless Communications
Author: Leonardo Jiménez RodríguezPublisher: Springer
ISBN: 3319179810
Category : Computers
Languages : en
Pages : 133
Book Description
This SpringerBrief explores the advantage of relaying techniques in addressing the increasing demand for high data rates and reliable services over the air. It demonstrates how to design cost-effective relay systems that provide high spectral efficiency and fully exploit the diversity of the relay channel. The brief covers advances in achievable rates, power allocation schemes, and error performance for half-duplex (HD) and full-duplex (FD) amplify-and-forward (AF) single-relay systems. The authors discuss the capacity and respective optimal power allocation for a wide range of HD protocols over static and fading channels. Then, optimal amplification coefficients in terms of achievable rate are presented. Chapters also examine performance with finite constellations, including the error and diversity performance. The brief concludes with a capacity and error performance analysis of the FD relay mode of operation, where the residual self-interference due to FD transmission is explicitly taken into account. Amplify-and-Forward Relaying in Wireless Communications reveals the benefits and challenges of relaying techniques. It is designed for researchers and professionals in wireless communication. This material is also appropriate for advanced-level students in electrical engineering and computer science.
Ofdm Based Relay Systems for Future Wireless Communications
Author: Milica Pejanovic-DjurisicPublisher: CRC Press
ISBN: 1000794008
Category : Science
Languages : en
Pages : 185
Book Description
Relay systems have become a subject of intensive research interest over the recent years, as it is recognized that they can improve performances and extend the coverage area of wireless communication systems. Special attention has been dedicated to them since the proposal appeared for their implementation in mobile cellular systems. Numerous researches conducted after that proposal have enabled incorporation of OFDM based relay systems in both accepted standards for IMT-Advanced systems. Nowadays, researches are ongoing with the aim to define new solutions for performance improvement of the standardized OFDM relay systems for cellular networks and one of the interesting solutions is implementation of subcarrier permutation (SCP) at the relay (R) station.The book OFDM based relay systems for future wireless communications presents a comprehensive research results in analyzing behavior and performance of the OFDM based relay systems with SCP. Dual-hop relay scenario with three communication terminals, and no direct link between the source (S) and the destination (D) has been analyzed, as it is compliant with the accepted solutions for IMT-Advanced systems. The book includes performance analysis and performance comparison of OFDM based:• amplify-and-forward (AF) relay systems with fixed gain (FG),• amplify-and-forward (AF) relay systems with variable gain (VG),• decode-and-forward (DF) relay systems,each including two SCP schemes, known to maximize the system capacity and/or improve the bit error rate (BER) performances. Performance comparisons have enabled definition of optimal solutions for the future wireless communication systems in a given conditions, and for the given optimality criteria. OFDM based relay systems for future wireless communications contains recent research results in this area and is ideal for the academic staff and master/research students in area of mobile communication systems, as well as for the personnel in communication industry.
Performance Analysis of RIS-assisted Relay Systems
Author: Alan DevkotaPublisher:
ISBN:
Category : Adaptive control systems
Languages : en
Pages : 0
Book Description
Reconfigurable intelligent surface (RISs) have been viewed as a vital physical-layer transmission technology for next-generation wireless systems. While the current state-of-art wireless standard is the fifth generation (5G), the RISs have emerged as a novel option to satisfy the rising demands for higher data rates, improved network coverage, increased reliability, and energy efficiency in wireless communications for sixth-generation (6G) and beyond. The spectral and energy efficiency requirement is one of the fundamental design elements of any communication system design. The need for greener communication technologies for wireless networks has laid the groundwork for many innovative wireless power transfer methods. Due to the fact that radio-frequency (RF) signals can convey both information and energy simultaneously, there has been much research interest in designing novel technologies for simultaneous wireless information and power transmission (SWIPT) and energy harvesting (EH). Firstly, an RIS-assisted relay system model is proposed to improve the wireless system performance. By characterizing the optimal signal-to-noise ratio (SNR) attained through intelligent phase-shift controlling, the performance of the RIS-assisted relay system is investigated. To this end, the cumulative distribution function of the optimal SNR is derived by using a tight approximation. Thereby, tight approximations for the achievable rate, outage probability, and the average symbol error rate are derived. Thereby, the impact of phase-shift errors is studied by adopting discrete phase-shift adjustments. Then, by using the Monte-Carlo simulations, the validity of our theoretical results is verified. Finally, a set of insightful numerical results has been presented to evaluate the performance gains offered by the proposed RIS-assisted relay system. Secondly, the performance of simultaneous wireless information and power transfer (SWIPT) is explored for the proposed RIS-assisted relay system. Towards this end, tight bounds for the average achievable rate and optimal harvested energy are derived in closed-form for a hybrid SWIPT protocol. Then, the achievable rate-energy trade-off is derived. Thereby, the detrimental effects of phase quantization in the optimal SNR, achievable rate, and harvested energy are explored. Furthermore, the impact of varying the time-switching factor, power-splitting factor, numbers of reflective elements, and coefficient of reflection on the performance of the proposed RIS-aided is studied. Also, the performance of linear EH models and non-linear EH models are compared via analytical and Monte-Carlo simulations results. The corresponding analysis reveals that the rate-energy trade-off is highly sensitive to the number of passive reflecting elements and the number of bits used in the RIS phase-shift quantization procedure. Furthermore, it is observed that the linear EH models overestimate the harvested energy, implying that the non-linear EH models are more appropriate than their the linear counterparts for investigating performance of SWIPT with RIS-assisted relay networks.
Topics in the Performance Analysis of Wireless Communication System
Author: Mazen O. HasnaAnalysis and Optimization for Robust Millimeter-Wave Communications
Author: Cristian TatinoPublisher: Linköping University Electronic Press
ISBN: 917929734X
Category : Electronic books
Languages : en
Pages : 53
Book Description
Spectrum scarcity is a longstanding problem in mobile telecommunications networks. Specifically, accommodating the ever-growing data rate and communications demand in the extensively used spectrum between 800 MHz and 6 GHz is becoming more challenging. For this reason, in the last years, communications in the millimeterwave (mm-wave) frequency range (30-300 GHz) have attracted the interest of many researchers, who consider mm-wave communications a key enabler for upcoming generations of mobile communications, i.e., 5G and 6G. However, the signal propagation in the mm-wave frequency range is subject to more challenging conditions. High path loss and penetration loss may lead to short-range communications and frequent transmission interruptions when the signal path between the transmitter and the receiver is blocked. In this dissertation, we analyze and optimize techniques that enhance the robustness and reliability of mm-wave communications. In the first part, we focus on approaches that allow user equipment (UE) to establish and maintain connections with multiple access points (APs) or relays, i.e., multi-connectivity (MC) and relaying techniques, to increase link failure robustness. In such scenarios, an inefficient link scheduling, i.e., over or under-provisioning of connections, can lead to either high interference and energy consumption or unsatisfied user’s quality of service (QoS) requirements. In the first paper, we propose a novel link scheduling algorithm for network throughput maximization with constrained resources and quantify the potential gain of MC. As a complementary approach, in the second paper, we solve the problem of minimizing allocated resources while satisfying users’ QoS requirements for mm-wave MC scenarios. To deal with the channel uncertainty and abrupt blockages, we propose a learning-based solution, of which the results highlight the tradeoff between reliability and allocated resource. In the third paper, we perform throughput and delay analysis of a multi-user mm-wave wireless network assisted by a relay. We show the benefits of cooperative networking and the effects of directional communications on relay-aided mm-wave communications. These, as highlighted by the results, are characterized by a tradeoff between throughput and delay and are highly affected by the beam alignment duration and transmission strategy (directional or broadcast). The second part of this dissertation focuses on problems related to mm-wave communications in industrial scenarios, where robots and new industrial applications require high data rates, and stringent reliability and latency requirements. In the fourth paper, we consider a multi-AP mm-wave wireless network covering an industrial plant where multiple moving robots need to be connected. We show how the joint optimization of robots’ paths and the robot-AP associations can increase mm-wave robustness by decreasing the number of handovers and avoiding coverage holes. Finally, the fifth paper considers scenarios where robot-AP communications are assisted by an intelligent reflective surface (IRS). We show that the joint optimization of beamforming and trajectory of the robot can minimize the motion energy consumption while satisfying time and communication QoS constraints. Moreover, the proposed solution exploits a radio map to prevent collisions with obstacles and to increase mm-wave communication robustness by avoiding poorly covered areas.
Analysis and Design of Communication Techniques in Spectrally Efficient Wireless Relaying Systems
Author: Jian ZhaoPublisher: Logos Verlag Berlin GmbH
ISBN: 3832525858
Category : Technology & Engineering
Languages : en
Pages : 286
Book Description
This dissertation studies the communication technologies in relaying systems with multiple antennas, especially in the multiple-input multiple-output (MIMO) two-way relaying systems. Both information-theoretic aspects and practical communication strategies are considered and analyzed. For the information-theoretic analysis, an analytical framework for the coverage of MIMO relaying systems based on an outage capacity criterion is proposed. For MIMO two-way relaying systems, different data combining schemes at the relay are compared based on their achievable rates. In addition, optimal time-division (TD) strategies for MIMO two-way decode-and-forward (DF) relaying systems are proposed and analyzed. When the optimal TD strategies are applied, the increase of the achievable rate regions in the system is significant compared to those using the equal TD strategy. For the practical transmission schemes, we propose the self-interference (SI) aided channel estimation and data detection schemes for the broadcast phase of two-way DF relaying systems. Such schemes exploit the SI in two-way DF relaying systems when the superposition coding (SPC) scheme is applied. When the network coding scheme is applied in two-way DF relaying systems, we propose an asymmetric data rate transmission scheme that utilizes the known data bits at the receivers. Such a scheme exploits the a priori known bits at the weak link receiver in the broadcast phase of two-way relaying systems.
Performance Analysis of Amplify-and-Forward Wireless Relay Networks
Author: Muhammad KhalilPublisher:
ISBN:
Category : Bit error rate
Languages : en
Pages : 284
Book Description
Wireless relay technology plays an important role in the next-generation mobile and wireless networks. It has been proposed as a cost effective solution to addressing a growing demand for high data rates and low power consumption. In the relay communication model, a source communicates to a destination through a wireless node(s) called a relay. There are two main relaying techniques: Decode-and-Forward (DF) and Amplify-and-Forward (AF). AF is the focus of this thesis. The AF relay networks provide considerable performance improvement in link reliability, Spectral Efficiency (SE), Energy Efficiency (EE) and Bit Error Rate (BER) performance. They also offer a low-complexity solution for practical relay networks that have critical energy constraints, as they enable the received signal to be amplified without the decoding process at the relays. This thesis proposes new methods of reducing the energy consumption and evaluating the error performance of AF relay networks, when the relay is either one-way (unidirectional) or two-way (bidirectional). The analysis is commenced by formulating the actual Signals-to-Noise Ratio (SNR) level, which corresponds to a low SNR level, in order to calculate the Exact Bit Error Rate (EBER) performance. Then, the approximated SNR, which refers to a high SNR level, is expressed and adopted to evaluate the Asymptotic Bit Error Rate (ABER). Another SNR level is presented in this work and defined as an optimal SNR level, which is obtained by optimal balancing of the SE and EE. The optimal SNR level allows evaluation of the ABER and the EBER of AF relay networks under optimal SNR conditions. Accordingly, a unifying BER evaluation at low, high, and optimal levels of AF relay networks is provided in this study. This thesis focuses on a high SNR level to derive an effective method for evaluating the ABER and EBER, whether in optimal or sub-optimal AF relay networks. The effectiveness of such a BER evaluation method is demonstrated by enhancing the ABER of AF relay networks at all SNR levels (i.e., low, high, optimal SNR levels). This is shown when disparity between the ABER and the EBER at a low SNR level is reduced, and this helps to calculate the accurate BER of AF relay networks under any SNR levels using either the ABER or EBER. The proposed methods are examined under different channels environments, as in practice the channel of each hop of an AF relay network can be located in a different environment. When both hops are located in the same environment, the fading channels of the hops are equal, while for different environments, the fading channels of the hops are different. Furthermore, relay location is also investigated for the aforementioned ABER and EBER, and a new method for determining the relationship between the EE and EBER with relay location is derived.
Molecular Communication
Author: Tadashi NakanoPublisher: Cambridge University Press
ISBN: 1107292387
Category : Technology & Engineering
Languages : en
Pages : 193
Book Description
This comprehensive guide, by pioneers in the field, brings together, for the first time, everything a new researcher, graduate student or industry practitioner needs to get started in molecular communication. Written with accessibility in mind, it requires little background knowledge, and provides a detailed introduction to the relevant aspects of biology and information theory, as well as coverage of practical systems. The authors start by describing biological nanomachines, the basics of biological molecular communication and the microorganisms that use it. They then proceed to engineered molecular communication and the molecular communication paradigm, with mathematical models of various types of molecular communication and a description of the information and communication theory of molecular communication. Finally, the practical aspects of designing molecular communication systems are presented, including a review of the key applications. Ideal for engineers and biologists looking to get up to speed on the current practice in this growing field.