Wireless OFDM Systems: How to make them work?

ISBN-13: 9781402071164 / Angielski / Twarda / 2002 / 206 str.

Marc Engels

Opis

Wireless Local Area Networks (WLANs) experience a growing popularity recently. Where WLANs were primarily used for niche applications in the past, they are now deployed as wireless extensions to computer networks. The increase of the datarates from 2 Mbps up to 11 Mbps for roughly a constant price has played a major role in this breakthrough. As a consequence, an even greater success can be envisioned for the more recent OFDM-based WLAN standards in the 5 GHz band, which offer up to 54 Mbps. At IMEC we have realised this potential already several years ago and have established a successful research programme on OF- based WLAN. In 1995, we started our research on wireless OFDM in the frame of a - operation project with SAIT, a Belgian telecom company. The goal of the project was to establish a robust network for industrial environments. This resulted in a first OFDM chip, supporting QPSK, for wireless networking at the end of the project (1999). 1999 was also the start of an intense co-operation with National Semiconductor Inc., which resulted in a second generation ASIC in 2000. This OFDM processor supports up to QAM-64 and has a more optimal channel estimation algorithm.

Recenzje

"This book...gives a comprehensive overview of the implementation of OFDM systems. It capitalizes on the large experience of the authors with the implementation of OFDM based WLAN system. For those who study or work on broadband communication in a wireless multipath environment, this book is a useful and easy-to-read reference..."
(Zongsen Wu, Shaowen Song and Tianying Ji, Physics and Computing Dept., Wilfrid Laurier University, ON)

Spis treści

List of Figures. List of Tables. Preface. Contributors. Acknowledgements.Introduction. 1.1. A connected world emerges. 1.2. Wireless OFDM: the next technology wave. 1.3. WirelessOFDM systems. 1.4. Structure of the book. Understanding the indoor environment. 2.1. Introduction. 2.2. Propagation losses. 2.3. Multipath propagation. 2.4. Time variant channels. 2.5. Conclusions. The OFDM Principle 3.1. The OFDM principle. 3.2. The OFDM system model. 3.3. What if the channel is time-variant? 3.4. OFDM receiver performance. 3.5. Coding: an essential ingredient. 3.6. Summary. When people agree on OFDM. 4.1. WLAN standards.4.2. HIPERLAN/2.4.3. Differences between HIPERLAN/2 and IEEE 802.11a. Beating the wireless channel. 5.1. Introduction. 5.2. Channel models and characteristics. 5.3. One-Dimensional Channel Estimators. 5.4. Two-Dimensional Channel estimators. Avoiding a tower of Babel. 6.1. Introduction. 6.2. Effects of out of sync transmission. 6.3. Timing synchronisation. 6.4. Frequency synchronisation. Living with a real radio 7.1. Introduction. 7.2. How the front-end impairs the OFDM modem. 7.3. A system simulation tool. 7.4. Analysis and simulation of the main front-end effects. 7.5. Conclusions. Putting it all together. 8.1. Introduction. 8.2. The basedband signal processing ASIC. 8.3. The discrete system set-up. 8.4. Learning from results. Abbreviations. Variables. Notation. Index.