There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Space-time codes (STC) are a class of signaling techniques, offering coding and diversity gains along with improved spectral efficiency. These codes exploit both the spatial and the temporal diversity of the wireless link by combining the design of the error correction code, modulation scheme and array processing. STC are well suited for improving the downlink performance, which is the bottleneck in asymmetric applications such as downstream Internet. Three original contributions to the area of STC are presented in this dissertation. First, the development of analytic tools that determine the fundamental limits on the performance of STC in a variety of channel conditions. For trellis-type STC, transfer function based techniques are applied to derive performance bounds over Rayleigh, Rician and correlated fading environments. For block-type STC, an analytic framework that supports various complex orthogonal designs with arbitrary signal cardinalities and array configurations is developed. In the second part of the dissertation, the Virginia Tech Space-Time Advanced Radio (VT-STAR) is designed, introducing a multi-antenna hardware laboratory test bed, which facilitates characterization of the multiple-input multiple-output (MIMO) channel and validation of various space-time approaches. In the third part of the dissertation, two novel space-time architectures paired with iterative processing principles are proposed. The first scheme extends the suitability of STC to outdoor wireless communications by employing iterative equalization/decoding for time dispersive channels and the second scheme employs iterative interference cancellation/decoding to solve the error propagation problem of Bell-Labs Layered Space-Time Architecture (BLAST). Results show that remarkable energy and spectral efficiencies are achievable by combining concepts drawn from space-time coding, multiuser detection, array processing and iterative decoding.

Space-Time Codes for High Data Rate Wireless Communications

Device-to-device (D2D) communications was initially proposed in cellular networks as a new paradigm for enhancing network performance. The emergence of new applications such as content distribution and location-aware advertisement introduced new user cases for D2D communications in cellular networks. The initial studies showed that D2D communications has advantages such as increased spectral efficiency and reduced communication delay. However, this communication mode introduces complications in terms of interference control overhead and protocols that are still open research problems. The feasibility of D2D communications in Long-Term Evolution Advanced is being studied by academia, industry, and standardization bodies. To date, there are more than 100 papers available on D2D communications in cellular networks, but there is no survey on this field. In this paper, we provide a taxonomy based on the D2D communicating spectrum and review the available literature extensively under the proposed taxonomy. Moreover, we provide new insights into the over-explored and under-explored areas that lead us to identify open research problems of D2D communications in cellular networks.

https://eprints.networks.imdea.org/id/document/2488

A Survey on Device-to-Device Communication in Cellular Networks

Device-to-Device (D2D) communication was initially proposed in cellular networks as a new paradigm to enhance network performance. The emergence of new applications such as content distribution and location-aware advertisement introduced new use-cases for D2D communications in cellular networks. The initial studies showed that D2D communication has advantages such as increased spectral efficiency and reduced communication delay. However, this communication mode introduces complications in terms of interference control overhead and protocols that are still open research problems. The feasibility of D2D communications in LTE-A is being studied by academia, industry, and the standardization bodies. To date, there are more than 100 papers available on D2D communications in cellular networks and, there is no survey on this field. In this article, we provide a taxonomy based on the D2D communicating spectrum and review the available literature extensively under the proposed taxonomy. Moreover, we provide new insights to the over-explored and under-explored areas which lead us to identify open research problems of D2D communication in cellular networks.

This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

Cooperation in Wireless Networks: Principles and Applications covers the underlying principles of cooperative techniques as well as several applications demonstrating the use of such techniques in practical systems. The work is written in a collaborative manner by several authors from Asia, America, and Europe. Twenty chapters introduce and discuss in detail the main cooperative strategies for the whole communication protocol stack from the application layer down to the physical layer. Furthermore power saving strategies, security, hardware realization, and user scenarios for cooperative communication systems are introduced and discussed. The book also summarizes the strength of cooperation for upcoming generation of wireless communication systems, clearly motivating the use of cooperative techniques and pointing out that cooperation will become one of the key technologies enabling 4G and beyond. This book puts into one volume a comprehensive and technically rich view of the wireless communications scene from a cooperation point of view.

Cooperation in Wireless Networks: Principles and Applications

This white paper explores the road to implementing broadband connectivity in future 6G wireless systems. Different categories of use cases are considered, from extreme capacity with peak data rates up to 1 Tbps, to raising the typical data rates by orders-of-magnitude, to support broadband connectivity at railway speeds up to 1000 km/h. To achieve these goals, not only the terrestrial networks will be evolved but they will also be integrated with satellite networks, all facilitating autonomous systems and various interconnected structures. We believe that several categories of enablers at the infrastructure, spectrum, and protocol/ algorithmic levels are required to realize the intended broadband connectivity goals in 6G. At the infrastructure level, we consider ultra-massive MIMO technology (possibly implemented using holographic radio), intelligent reflecting surfaces, user-centric and scalable cell-free networking, integrated access and backhaul, and integrated space and terrestrial networks. At the spectrum level, the network must seamlessly utilize sub-6 GHz bands for coverage and spatial multiplexing of many devices, while higher bands will be used for pushing the peak rates of point-to-point links. The latter path will lead to THz communications complemented by visible light communications in specific scenarios. At the protocol/algorithmic level, the enablers include improved coding, modulation, and waveforms to achieve lower latencies, higher reliability, and reduced complexity. Different options will be needed to optimally support different use cases. The resource efficiency can be further improved by using various combinations of full-duplex radios, interference management based on rate-splitting, machine-learning-based optimization, coded caching, and broadcasting.

White Paper on Broadband Connectivity in 6G

A method includes receiving at least two space-time coded signals from an antenna system associated with a first station, determining complex channel state information based on the received space-time coded signals, and sending the complex channel state information to the first station. In an alternative embodiment, a method includes transmitting at least two space-time coded signals in respective beams of a multi-beam antenna array, measuring a channel impulse response for each space-time coded signal at a second station, and sending an indicia of a selected set of least attenuated signals from the second station to the first station. The multi-beam antenna array is associated with a first station. The beams transmit a signature code embedded in each respective space-time coded signal, and the signature codes are orthogonal so that the second station can separate and measure the channel impulse response corresponding to each space-time coded signal. The space-time coded signals include the selected set of least attenuated signals and a remaining set of most attenuated signals. In an alternative embodiment, a method includes selecting at least two beams of plural beams formed by a multi-beam antenna array associated with a first station for transmission of a corresponding at least two space-time coded signals produced by a space-time encoder, determining a time delay associated with each of the at least two space-time coded signals as received in each respective beam, and setting into a variable delay line the time delay corresponding to each beam, each variable delay line being coupled between the multi-beam antenna array the space-time encoder.

Closed loop feedback system for improved down link performance

Dedication. List of Figures. List of Tables. Contributing Authors. Foreword. Foreword. Acknowledgments. Preface. 1. Cooperation in Nature and Wireless Communications Frank H. P. Fitzek and Marcos Katz. 1. Basics of Cooperation. 2. The Prisoner's Dilemma. 3. The Iterated Prisoner's Dilemma. 4. N-person Prisoner's Dilemma. 5. Stimulating Cooperative Behavior. 6. Cooperation in Wireless Communication Systems. 7. Cooperative Principles in Wireless Communications: The Future. 8. Conclusion. References. 2. Cooperative Communications Arnab Chakrabarti, Ashutosh Sabharwal and Behnaam Aazhang. 1. Introduction. 2. A Brief History of Relaying. 3. Preliminaries of Relaying. 4. Relaying : Fundamental Limits. 5. Practical Strategies for Relaying Information. 6. Conclusion. References. 3. Cooperation, Competition and Cognition in Wireless Networks Oh-Soon Shin, Natasha Devroye, Patrick Mitran, Hideki Ochiai, Saeed S. Ghassemzadeh, H. T. Kung and Vahid Tarokh. 1. Introduction. 2. Cooperative Diversity. 3. Cooperative Beamforming. 4. Cognitive Radio. 5. Summary and Remarks. References. 4. Cooperation Techniques in Cross-layer Design Shuguang Cui and Andrea J. Goldsmith. 1. Introduction. 2. Cross-layer Design. 3. Node Cooperation in Wireless Networks. 4. Node Cooperation with Cross-layer Design. 5. Design Examples. References. 5. Network Coding in Wireless Networks Tracey Ho, Ralf Koetter, Desmond S. Lun, Muriel Medard and Niranjan Ratnakar.1. Introduction. 2. Model. 3. Distributed random network coding. 4. Cost minimization. 5. Further directions and results. References. 6. Cooperative Diversity: Models, Algorithms, and Architectures J. Nicholas Laneman. 1. Introduction. 2. Elements of Cooperative Diversity. 3. Cooperative Diversity in Existing Network Architectures. 4. Discussion and FutureDirections. References. 7. Cooperation in Ad-Hoc Networks Petri Mahonen, Marina Petrova and Janne Riihijarvi. 1. Introduction. 2. Limits of Multihop. 3. Spectrum Cooperation. 4. Topology Aware Ad Hoc Networks. 5. Hybrid Networks and 4G. 6. Discussion and Conclusions. Acknowledgments. References. 8. Multi-route and Multi-user Diversity in Infrastructure-based Multi-hop Networks Keivan Navaie and Halim Yanikomeroglu. 1. Introduction. 2. Multi-route Diversity and Multi-user Diversity. 3. Cooperative Induced Multi-user Diversity Routing for Multi-hop Infrastructurebased Networks with Mobile Relays. 4. Simulation Results. 5. Conclusion. References. 9. Cognitive Radio Architecture Joseph Mitola III. 1. Introduction. 2. Architecture. 3. CRA I: Functions, Components and Design Rules. 4. CRA II: The Cognition Cycle. 5. CRA III: The Inference Hierarchy. 6. CRA IV: Architecture Maps. 7. CRA V: Building the CRA on SDR Architectures. 8. Commercial CRA. 9. Future Direction. References. 10 Stability and Security in Wireless Cooperative Networks Konrad Wrona and Petri Mahonen. 1. Introduction. 2. Sustaining cooperation. 3. Dynamics of cooperative communication systems. 4. Conclusions and discussion. References. 11. Power Consumption and Spectrum Usage Paradigms in Cooperative Wireless Networks Frank H. P. Fitzek, Persefoni Kyritsi and Marcos Katz. 1. Motivation. 2. System under Investigation. 3. Time Division Multiple Access Cooperation. 4. Orthogonal Frequency Division Multiple Access Cooperation.5. Conclusion. References. 12. Cooperative Antenna Systems Patrick C.F. Eggers, Persefoni Kyritsi and Istvan Z. Kovacs. 1. Introducing antenna cooperation. 2. Antenna systems and algorithms : foundations and principles. 3. Channel conditions, measurements and modeling : Practical

Cooperation in Wireless Networks: Principles and Applications: Real Egoistic Behavior Is to Cooperate!

A method of directional radio communication between a first station and a second station comprises the steps of determining from at least one signal received at the first station from the second station which of a plurality of different radio environment types is present between said first and second stations. A signal is transmitted from the first station to the second station with at least one parameter of said transmitted signal being dependent on the determined radio environment type.

Marcos Katz

Papers

Cooperation in Wireless Networks: Principles and Applications

White Paper on Broadband Connectivity in 6G

Closed loop feedback system for improved down link performance

Cooperation in Wireless Networks: Principles and Applications: Real Egoistic Behavior Is to Cooperate!

Method and apparatus for directional radio communication