Providing key background material together with advanced topics, this self-contained book is written in an easy-to-read style and is ideal for newcomers to multicarrier systems. Early chapters provide a review of basic digital communication, starting from the equivalent discrete time channel and including a detailed review of the MMSE receiver. Later chapters then provide extensive performance analysis of OFDM and DMT systems, with discussions of many practical issues such as implementation and power spectrum considerations. Throughout, theoretical analysis is presented alongside practical design considerations, whilst the filter bank transceiver representation of OFDM and DMT systems opens up possibilities for further optimization such as minimum bit error rate, minimum transmission power, and higher spectral efficiency. With plenty of insightful real-world examples and carefully designed end-of-chapter problems this is an ideal single-semester textbook for senior undergraduate and graduate students, as well as a self-study guide for researchers and professional engineers.

DFT modulated filter banks for non-orthogonal multicarrier transmission are considered a strong tool to implement both dynamic spectrum access and spectrum sensing in cognitive radio systems where signaling schemes have to meet different objectives. A constrained optimization approach is presented to design a cognitive radio transceiver which can be tailored to system specifications with a reasonable trade-off between performance and implementation efficiency. In interweave cognitive radio, the secondary user receiver is synchronized in time and frequency by designing a synthesis filter bank preamble with periodic symbols in analogy to short training fields in IEEE 802.11a. A simple post-detection integration at the secondary user receiver is employed for differently coherent detection. In underlay cognitive radio, a novel transmission scheme for secondary user power adaptation is proposed aiming to minimize the secondary user average probability of error for bit-interleaved coded modulation. The powers of the subcarrier signals are adapted subject to total power and stochastic chance-based interference constraints in order to provide a confidence level for limiting the interference at the licensed primary user receiver.

The demand for data traffic over mobile communication networks has substantially increased during the last decade. As a result, these mobile broadband devices spend the available spectrum fiercely, requiring the search for new technologies. In transmissions where the channel presents a frequency-selective behavior, multicarrier modulation (MCM) schemes have proven to be more efficient, in terms of spectral usage, than conventional modulations and spread spectrum techniques. The orthogonal frequency-division multiplexing (OFDM) is the most popular MCM method, since it not only increases spectral efficiency but also yields simple transceivers. All OFDM-based systems, including the single-carrier with frequency-division equalization (SC-FD), transmit redundancy in order to cope with the problem of interference among symbols. This book presents OFDM-inspired systems that are able to, at most, halve the amount of redundancy used by OFDM systems while keeping the computational complexity comparable. Such systems, herein called memoryless linear time-invariant (LTI) transceivers with reduced redundancy, require low-complexity arithmetical operations and fast algorithms. In addition, whenever the block transmitter and receiver have memory and/or are linear time-varying (LTV), it is possible to reduce the redundancy in the transmission even further, as also discussed in this book. For the transceivers with memory it is possible to eliminate the redundancy at the cost of making the channel equalization more difficult. Moreover, when time-varying block transceivers are also employed, then the amount of redundancy can be as low as a single symbol per block, regardless of the size of the channel memory. With the techniques presented in the book it is possible to address what lies beyond the use of OFDM-related solutions in broadband transmissions. Table of Contents: The Big Picture / Transmultiplexers / OFDM / Memoryless LTI Transceivers with Reduced Redundancy / FIR LTV Transceivers with Reduced Redundancy

The demand for data traffic over mobile communication networks has substantially increased during the last decade. As a result, these mobile broadband devices spend the available spectrum fiercely, requiring the search for new technologies. In transmissions where the channel presents a frequency-selective behavior, multicarrier modulation (MCM) schemes have proven to be more efficient, in terms of spectral usage, than conventional modulations and spread spectrum techniques. The orthogonal frequency-division multiplexing (OFDM) is the most popular MCM method, since it not only increases spectral efficiency but also yields simple transceivers. All OFDM-based systems, including the single-carrier with frequency-division equalization (SC-FD), transmit redundancy in order to cope with the problem of interference among symbols. This book presents OFDM-inspired systems that are able to, at most, halve the amount of redundancy used by OFDM systems while keeping the computational complexity comparable. Such systems, herein called memoryless linear time-invariant (LTI) transceivers with reduced redundancy, require low-complexity arithmetical operations and fast algorithms. In addition, whenever the block transmitter and receiver have memory and/or are linear time-varying (LTV), it is possible to reduce the redundancy in the transmission even further, as also discussed in this book. For the transceivers with memory it is possible to eliminate the redundancy at the cost of making the channel equalization more difficult. Moreover, when time-varying block transceivers are also employed, then the amount of redundancy can be as low as a single symbol per block, regardless of the size of the channel memory. With the techniques presented in the book it is possible to address what lies beyond the use of OFDM-related solutions in broadband transmissions. Table of Contents: The Big Picture / Transmultiplexers / OFDM / Memoryless LTI Transceivers with Reduced Redundancy / FIR LTV Transceivers with Reduced Redundancy

"Multicarrier modulation (MCM) is an efficient transmission technique for high data rate wired and wireless communications, where the channel bandwidth is divided into several subchannels with their own carriers. There are many different possible realizations for MCM systems, but with no doubt, orthogonal frequency division multiplexing (OFDM) has been the most prevalent solution in many current applications and standards. However, due to its use of a rectangular prototype filter, channel impairments such as narrowband interference (NBI) and carrier frequency offset (CFO) can greatly deteriorate the performance of OFDM. Moreover, future telecommunication networks call for higher data rate, increased bandwidth efficiency and flexibility in handling unsynchronized users. Filter bank multicarrier (FBMC) techniques have recently attracted considerable attention within the research community as a venue to fulfill these needs and potentially outperform the established OFDM in application areas such as dynamic spectrum access (DSA) and cognitive radio.In this context, we first propose a novel method for the design of discrete Fourier transform (DFT) modulated oversampled perfect reconstruction filter bank (OPRFB), for transmultiplexing application in MCM systems. The perfect reconstruction (PR) property is enforced by employing a parametric class of paraunitary matrices to form the transmit/receive polyphase filters of the transceiver system. Specifically, the polyphase filters are obtained by cascading special types of paraunitary matrices characterized by a limited set of design parameters. To reduce the number of these parameters, three different factorization methods are employed and compared. Through the optimization of these design parameters, the stop-band energy of the subband filters can be minimized which leads to improved spectral containment. Numerical results show that the proposed scheme leads to a clear advantage not only in additive white Gaussian noise (AWGN) and frequency selective channels, but also in the presence of channel impairments such as NBI or CFO. In particular, it is found that a significant reduction in the bit error rate (BER) can be achieved by employing the proposed scheme. Secondly, still in the context of single-user systems, we derive a data-aided joint maximum likelihood (ML) estimator of the CFO and the channel impulse response (CIR) for OPRFB transceiver systems operating over frequency selective fading channels. Then, by exploiting the structural and spectral properties of these systems, we are able to considerably reduce the complexity of the proposed estimator through simplifications of the underlying likelihood function. The Cramer Rao bound (CRB) on the variance of unbiased CFO and CIR estimators is also derived. The performance of the proposed ML estimator is investigated by means of numerical simulations under realistic conditions with CFO and frequency selective fading channels. The effects of different pilot schemes on the estimation performance for applications over time-invariant and mobile time-varying channels are also examined. The results show that the proposed joint ML estimator exhibits an excellent performance, where it can accurately estimate the unknown CFO and CIR parameters for the various experimental setups under consideration.Our third and final contribution deals with the extension of these newly proposed estimators to the multi-user case. More specifically, we consider the joint estimation of the CFO and channel equalizer coefficients based on the ML principle in the uplink of multi-user OPRFB (MU-OPRFB) systems. The performance of the proposed joint ML estimator is examined for various subband allocation schemes by means of numerical simulations. Also, different distributions of pilots over time are considered and their effects are investigated over mobile time-varying channels." --

This comprehensive resource provides the latest information on digitization and reconstruction (D&R) of analog signals in digital radios. Readers learn how to conduct comprehensive analysis, concisely describe the major signal processing procedures carried out in the radios, and demonstrate the dependence of these procedures on the quality of D&R. The book presents and analyzes the most promising and theoretically sound ways to improve the characteristics of D&R circuits and illustrate the influence of these improvements on the capabilities of digital radios. The book is intended to bridge the gap that exists between theorists and practical engineers developing D&R techniques by introducing new signal transmission and reception methods that can effectively utilize the unique capabilities offered by novel digitization and reconstruction techniques.