Hierarchical colour-shift-keying aided layered video streaming for the visible light downlink

Colour-shift keying (CSK) constitutes an important modulation scheme conceived for the visible light communications (VLC). The signal constellation of CSK relies on three different-color light sources invoked for information transmission. The CSK constellation has been optimized for minimizing the bit error rate, but no effort has been invested in investigating the feasibility of CSK aided unequal error protection (UEP) schemes conceived for video sources. Hence, in this treatise, we conceive a hierarchical CSK (HCSK) modulation scheme based on the traditional CSK, which is capable of generating interdependent layers of signals having different error probability, which can be readily reconfigured by changing its parameters. Furthermore, we conceived an HCSK design example for transmitting scalable video sources with the aid of a recursive systematic convolutional (RSC) code. An optimization method is conceived for enhancing the UEP and for improving the quality of the received video. Our simulation results show that the proposed optimized-UEP 16-HCSK-RSC system outperforms the traditional equal error protection scheme by ~ 1.7 dB of optical SNR at a peak signal-to-noise ratio of 37 dB, while optical SNR savings of up to 6.5 dB are attained at a lower PSNR of 36 dB

Cooperative Transmission Techniques in Wireless Communication Networks

Cooperative communication networks have received significant interests from both academia and industry in the past decade due to its ability to provide spatial diversity without the need of implementing multiple transmit and/or receive antennas at the end-user terminals. These new communication networks have inspired novel ideas and approaches to find out what and how performance improvement can be provided with cooperative communications. The objective of this thesis is to design and analyze various cooperative transmission techniques under the two common relaying signal processing methods, namely decode-and-forward (DF) and amplify-and-forward (AF). For the DF method, the thesis focuses on providing performance improvement by mitigating detection errors at the relay(s). In particular, the relaying action is implemented adaptively to reduce the phenomenon of error propagation: whether or not a relay’s decision to retransmit depends on its decision variable and a predefined threshold. First, under the scenario that unequal error protection is employed to transmit different information classes at the source, a relaying protocol in a singlerelay network is proposed and its error performance is evaluated. It is shown that by setting the optimal signal-to-noise ratio (SNR) thresholds at the relay for different information classes, the overall error performance can be significantly improved. Second, for multiple-relay networks, a relay selection protocol, also based on SNR thresholds, is proposed and the optimal thresholds are also provided. Third, an adaptive relaying protocol and a low-complexity receiver are proposed when binary frequency-shift-keying (FSK) modulation is employed and neither the receiver nor the transmitter knows the fading coefficients. It is demonstrated that large performance improvements are possible when the optimal thresholds are implemented at the relays and destination. Finally, under the scenario that there is information feedback from the destination to the relays, a novel protocol is developed to achieve the maximum transmission throughput over a multiple-relay network while the bit-error rate satisfies a given constraint. With the AF method, the thesis examines a fixed-gain multiple-relay network in which the channels are temporally-correlated Rayleigh flat fading. Developed is a general framework for maximum-ratio-combining detection when M-FSK modulation is used and no channel state information is available at the destination. In particular, an upper-bound expression on the system’s error performance is derived and used to verify that the system achieves the maximal diversity order. Simulation results demonstrate that the proposed scheme outperforms the existing schemes for the multiple-relay network under consideration

Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression

Heterogeneous Traffic Multiplexing in Next Generation Cellular Networks

The vision shaping the upcoming sixth-generation (6G) wireless cellular networks has recently gained considerable attention from researchers in academia and industry. 6G networks are expected to fulfill the limitations of the fifth-generation (5G) networks and support a wide range of new applications and services beyond those supported by 5G, namely, enhanced mobile broadband (eMBB), ultra-reliable and low latency communications (URLLC) and massive machine-type communications (mMTC). Further, these emerging networks are thus mandated to support new emerging applications that concurrently demand multiple quality of service (QoS) requirements of data rate, reliability, latency, and connectivity. Due to the fundamental trade-off of such extremely diverse QoS requirements, the coexistence of these emerging applications has been identified as a major challenge in 6G networks and their predecessors. This dissertation aims at addressing the coexistence problem, specifically URLLC and eMBB traffic, by developing spectrally efficient multiplexing and scheduling solutions. By considering different key enabling technologies, this dissertation provides unique research contributions to the coexistence problem that led to effective designs. In particular, coupling URLLC and eMBB through the Third Generation Partnership Project (3GPP) superposition/puncturing scheme naturally arises as a promising option due to the latter's tolerance in terms of latency and reliability. Moreover, reconfigurable intelligent surface (RIS) has been proposed as a potential low-cost and energy-efficient technology that can control the wireless propagation environment providing endless benefits in supporting coexisting 6G services. Regarding the superposition scheme, this thesis investigates the joint scheduling of eMBB and URLLC traffic while minimizing the eMBB rate loss, considering URLLC reliability and the eMBB QoS. In the context of puncturing, this thesis studied the interplay between the RIS configuration, URLLC reliability and eMBB rate by proposing proactive RIS configurations to guarantee the URLLC latency requirements. Although simulation results demonstrate that adopting the proposed scheme can further boost eMBB and URLLC traffic performance, the computational complexity of optimizing the RIS phase shifts is challenging. To this end, this thesis proposes two low-complexity methods for optimizing the RIS phase shift matrix. The first solution proposes reducing the number of optimization variables configuring the RIS to the number of users. The second algorithm is based on a closed-form expression for the RIS phase shift matrix. Finally, a new puncturing strategy is proposed to mitigate the impact on the eMBB transmission. The key idea of the proposed scheme is to puncture the eMBB data that has maximum symbol similarities with the URLLC leading to reducing the contaminated eMBB symbols. We study the performance of the proposed schemes in terms of the eMBB spectral efficiency, URLLC reliability and low complexity. We show analytically and through simulations the efficacy of the proposed schemes over their existing counterparts

Applications of MATLAB in Science and Engineering

The book consists of 24 chapters illustrating a wide range of areas where MATLAB tools are applied. These areas include mathematics, physics, chemistry and chemical engineering, mechanical engineering, biological (molecular biology) and medical sciences, communication and control systems, digital signal, image and video processing, system modeling and simulation. Many interesting problems have been included throughout the book, and its contents will be beneficial for students and professionals in wide areas of interest

Cooperative Radio Communications for Green Smart Environments

The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin

Cooperative Radio Communications for Green Smart Environments

The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin

Proceedings of the Fifth International Mobile Satellite Conference 1997

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial communications services. While previous International Mobile Satellite Conferences have concentrated on technical advances and the increasing worldwide commercial activities, this conference focuses on the next generation of mobile satellite services. The approximately 80 papers included here cover sessions in the following areas: networking and protocols; code division multiple access technologies; demand, economics and technology issues; current and planned systems; propagation; terminal technology; modulation and coding advances; spacecraft technology; advanced systems; and applications and experiments