Efficiency and security are major concerns with increasingly higher importance in modern wireless communications. These two concerns are especially significant for multi-user wireless communications where different users share or compete for resources. Among different users, there are possibilities of cooperation, competition, and/or malicious behavior. Due to the possibility of cooperation among the users, the spectral and energy efficiency in multi-user wireless communications could be boosted. Due to the possibility of competition, the resource allocation in multi-user wireless systems may reach certain equilibrium. Due to the possibility of malicious behavior, the security and reliability of wireless communications can be undermined. In this thesis, a comprehensive analysis on the issues of efficiency and security in multi-user wireless communications is developed for three systems in four scenarios. The first multi-user system of multiple-input multiple-output two-way relaying has the feature of cooperation including a limited coordination scenario and a full coordination scenario. It is shown that high spectral efficiency can be achieved with efficient energy consumption in this system due to the cooperation among the users. Moreover, full coordination yields better results in both spectral and energy efficiency than limited coordination at the cost of higher overhead. The second multi-user system of legitimate transceiver(s) with a jammer features the existence of malicious behavior. To measure the jamming threat, the worst-case jamming is studied for different cases according to the jammer's knowledge of the legitimate communication. The optimal/sub-optimal jamming strategy in each case is analyzed and derived. The third multi-user system of two-user interference channel features the competition of the users. The situation is modeled using noncooperative games with continuous mixed strategies. The outcomes of the games are analyzed through the establishment of the conditions for the existence and uniqueness of mixed strategy Nash equilibrium.

This book emphasis on multi-user MIMO communication. It covers a collection of the major topics and issues in multi-user MIMO systems. Recent Trends in Multi-user MIMO Communications provides a tutorial overview of the latest technologies and research keys related to multi-user communication. This book is composed of seven chapters, each written by a different set of authors. Features include: Fundamentals of multi-user MIMO communication, Random Beamforming in multi-user MIMO systems, LTE and LTE-Advanced framework, Interference cancellation in multi-user MIMO systems, Incorporation of multi-user capabilities in IEEE 802.11n/ac for WLAN systems, Physical layer security for multi-user MIMO communication, User selection based error probability of MIMO detector in multi-user MIMO systems.

This is volume 1 of a 2 volume set. This volume focuses on "channel estimation and equalization."

Orthogonal frequency-division multiplexing (OFDM) is a method of digital modulation in which a signal is split into several narrowband channels at different frequencies. CDMA is a form of multiplexing, which allows numerous signals to occupy a single transmission channel, optimising the use of available bandwidth. Multiplexing is sending multiple signals or streams of information on a carrier at the same time in the form of a single, complex signal and then recovering the separate signals at the receiving end. Multi-Carrier (MC) CDMA is a combined technique of Direct Sequence (DS) CDMA (Code Division Multiple Access) and OFDM techniques. It applies spreading sequences in the frequency domain. Wireless communications has witnessed a tremendous growth during the past decade and further spectacular enabling technology advances are expected in an effort to render ubiquitous wireless connectivity a reality. This technical in-depth book is unique in its detailed exposure of OFDM, MIMO-OFDM and MC-CDMA. A further attraction of the joint treatment of these topics is that it allows the reader to view their design trade-offs in a comparative context. Divided into three main parts: Part I provides a detailed exposure of OFDM designed for employment in various applications Part II is another design alternative applicable in the context of OFDM systems where the channel quality fluctuations observed are averaged out with the aid of frequency-domain spreading codes, which leads to the concept of MC-CDMA Part III discusses how to employ multiple antennas at the base station for the sake of supporting multiple users in the uplink Portrays the entire body of knowledge currently available on OFDM Provides the first complete treatment of OFDM, MIMO(Multiple Input Multiple Output)-OFDM and MC-CDMA Considers the benefits of channel coding and space time coding in the context of various application examples and features numerous complete system design examples Converts the lessons of Shannon’s information theory into design principles applicable to practical wireless systems Combines the benefits of a textbook with a research monograph where the depth of discussions progressively increase throughout the book This all-encompassing self-contained treatment will appeal to researchers, postgraduate students and academics, practising research and development engineers working for wireless communications and computer networking companies and senior undergraduate students and technical managers.

Detailing the advantages and limitations of multi-carrier communication, this book proposes possible solutions for these limitations. Multi-Carrier Communication Systems with Examples in MATLAB: A New Perspective addresses the two primary drawbacks of orthogonal frequency division multiplexing (OFDM) communication systems: the high sensitivity to c