Many and ever more mobile users wish to enjoy a variety of multimedia services, in very diverse geographical environments. The growing number of communication options within and across wireless standards is accommodating the growing volume and heterogeneity in wireless wishes. On the other hand, advancement in radio technologies opening much more flexibility, a.o. through Software Defined Radios, opens up the possibility to realize mobile devices featuring multi-mode options at low cost and interesting form factors.

It is crucial to manage the new degrees of freedom opened up in radios and standards in a smart way, such that the required service is offered at satisfactory quality as efficiently as possible. Efficiency in energy consumption is clearly primordial for battery powered mobile terminals specifically, and in the context of growing ecological concerns in a broader context. Moreover, efficient usage of the spectrum is a growing prerequisite for wireless systems, and coexistence of different standards puts overall throughput at risk.

The management of flexibility risks bringing about intolerable complexity and hamper the desired agility. A systematic approach, consisting of anticipative preparing for smooth operation, allows mastering this challenge. Case studies show that already today, this approach enables smart operation of radios realizing impressive efficiency gains without hampering Quality-of-Service. In the future wireless communication scenes will be able to profit form the opening of the spectrum. Even smarter and cognitive behavior will become possible and essential.

This volume proposes novel transmission techniques that achieve multi-path mitigation, through orthogonal frequency-domain processing, in combination with a high bandwidth efficiency, through space division multiple access. It also pays special attention to the real-world problems encountered when integrating core detection algorithms into a complete system.

PREFACE The increasing demand on high data rate and quality of service in wireless communication has to cope with limited bandwidth and energy resources. More than 50 years ago, Shannon has paved the way to optimal usage of bandwidth and energy resources by bounding the spectral efficiency vs. signal to noise ratio trade-off. However, as any information theorist, Shannon told us what is the best we can do but not how to do it [1]. In this view, turbo codes are like a dream come true: they allow approaching the theoretical Shannon capacity limit very closely. However, for the designer who wants to implement these codes, at first sight they appear to be a nightmare. We came a huge step closer in striving the theoretical limit, but see the historical axiom repeated on a different scale: we know we can achieve excellent performance with turbo codes, but not how to realize this in real devices.

Many and ever more mobile users wish to enjoy a variety of multimedia services, in very diverse geographical environments. The growing number of communication options within and across wireless standards is accommodating the growing volume and heterogeneity in wireless wishes. On the other hand, advancement in radio technologies opening much more flexibility, a.o. through Software Defined Radios, opens up the possibility to realize mobile devices featuring multi-mode options at low cost and interesting form factors.

It is crucial to manage the new degrees of freedom opened up in radios and standards in a smart way, such that the required service is offered at satisfactory quality as efficiently as possible. Efficiency in energy consumption is clearly primordial for battery powered mobile terminals specifically, and in the context of growing ecological concerns in a broader context. Moreover, efficient usage of the spectrum is a growing prerequisite for wireless systems, and coexistence of different standards puts overall throughput at risk.

The management of flexibility risks bringing about intolerable complexity and hamper the desired agility. A systematic approach, consisting of anticipative preparing for smooth operation, allows mastering this challenge. Case studies show that already today, this approach enables smart operation of radios realizing impressive efficiency gains without hampering Quality-of-Service. In the future wireless communication scenes will be able to profit form the opening of the spectrum. Even smarter and cognitive behavior will become possible and essential.

Green Software De?ned Radios, the title of this book may have originated from a lackofinspiration, andthecombinationofhardwork, jetlag, anddrinkinggreentea. The message we want to convey however, is that SDRs are a promising technology for the future, providing they are designed for ef?cient usage of scarce resources: energy and spectrum. In the last years, the R&D teams focusing on wireless c- munication (around the world and at IMEC speci?cally), have realized great bre- throughs. It is our honor, building on this knowledge, to bring a comprehensive overview of the essential technologies. We are grateful that Springer is willing to publish in their collection on radio technologies, a book on green SDRs, a weird species still today, yet maybe the baseline for the day after tomorrow. Dear reader, we wish that you ?nd in the following pages, including the references, some int- esting insights, and that this book may live more or less up to your expectations (and hopefully more than less). Thisbook'sclosingstatesthatthequestforGreenSDRshasnotended, thisisjust the beginning. Concerning this book however, we are happy that today the opposite is true. We want to acknowledge our colleagues at IMEC for their great scienti?c contribution, and even more for the enjoyable cooperation.

Green Software De?ned Radios, the title of this book may have originated from a lackofinspiration, andthecombinationofhardwork, jetlag, anddrinkinggreentea. The message we want to convey however, is that SDRs are a promising technology for the future, providing they are designed for ef?cient usage of scarce resources: energy and spectrum. In the last years, the R&D teams focusing on wireless c- munication (around the world and at IMEC speci?cally), have realized great bre- throughs. It is our honor, building on this knowledge, to bring a comprehensive overview of the essential technologies. We are grateful that Springer is willing to publish in their collection on radio technologies, a book on green SDRs, a weird species still today, yet maybe the baseline for the day after tomorrow. Dear reader, we wish that you ?nd in the following pages, including the references, some int- esting insights, and that this book may live more or less up to your expectations (and hopefully more than less). Thisbook'sclosingstatesthatthequestforGreenSDRshasnotended, thisisjust the beginning. Concerning this book however, we are happy that today the opposite is true. We want to acknowledge our colleagues at IMEC for their great scienti?c contribution, and even more for the enjoyable cooperation.

Turbo Codes: Desirable and Designable introduces the basics of turbo codes in their different flavors (more specifically, parallel concatenated convolutional turbo codes and block turbo codes). Through the application of systemic design methodology that considers data transfer and storage as top priority candidates for optimization, the authors show how turbo codes can be implemented and the attractive performance results that can be achieved in throughput, latency and energy consumption. These solutions and results make turbo-codes close competitors to traditional coding scheme such as convolutional codes or algebraic codes.

Finally, a real-life prototype of parallel concatenated convolutional (turbo-) codes is presented. A complete turbo codes ASIC data-flow is described together with on-board power, speed and coding gain measurements that demonstrate the effectiveness of the proposed solution.

This volume proposes novel transmission techniques that achieve multi-path mitigation, through orthogonal frequency-domain processing, in combination with a high bandwidth efficiency, through space division multiple access. It also pays special attention to the real-world problems encountered when integrating core detection algorithms into a complete system.