In late 2001, Bill Gates was having dinner with a group of journalists on the night before Microsoft’s launch of the Windows XP operating system. At that time, the dotcom crash was just unfolding, and during dinner, Bill Gates said (correctly) that the dotcom bubble was a distraction and caused a lot of money to be wasted on things that did not offer much innovation. Then Mr. Gates was asked if anything significant came out in the last few years.

“People will look back and say, ‘Wow, at least they did 802.11,’” he was quoted as replying [1].

He is right. Most of us today cannot imagine working (and living) without 802.11-based wireless networks, popularly known as Wi-Fi. Traveling professionals who really needed to send an e-mail and who had to drive around town looking for a hot spot can attest to the technology’s importance. At the end of the twentieth century and the beginning of the twenty-first century, people became used to highspeed wireless networking in the local area (i.e., hot spots). Similarly, as the twentyfirst century progresses, we will become used to high-speed mobile networking in the wide area (i.e., everywhere).

This book is designed as a broad examination of orthogonal frequency division multiplexing (OFDM) and orthogonal frequency division multiple access (OFDMA), which are fast becoming the de facto methods of transmission at the physical layer in broadband mobile systems. The associated functions necessary to support OFDM and OFDMA at layer 2 are also addressed. This book focuses on system analysis, design, and engineering of an OFDMA-based system, and it deals with both the theory and the application of OFDMA in the context of a broadband mobile wireless network. To the extent possible, based on the analysis of OFDMA, this book develops and presents applicable design frameworks in different areas of treatment.