Cooperative Communications: Hardware, Channel & PHY

1

Introduction

Wireless has become as much part of our lives as have houses, cars and computers. Mobile phones, an example application of wireless technologies, are indispensable today as they allow us to be connected anywhere at any time. We have, in fact, taken so much liking to wireless technologies that system capacity is reaching saturation levels. This is aggravated by recently emerged bandwidth hungry applications ranging from web browsing to multimedia transmissions. Network designers are struggling to meet this ever increasing demand in capacity and any means to increase capacity is hence welcome.

Interestingly, Martin Cooper of Arraycomm has observed that ‘the wireless capacity has doubled every 30 months over the last 104 years.’ This translates into an approximately million-fold capacity increase since the 1960s, which has been broken down [7] to yield a 25-times improvement from wider spectrum, a fivefold improvement by dividing the spectrum into smaller slices, a fivefold improvement by designing better modulation schemes, and an impressive 1600-fold gain through reduced cell sizes and transmit distance.

Among the many possible approaches to capitalize on these enticing gains, this book focuses on cooperation and we will show how cooperative techniques at the physical layer can potentially be of great benefit to capacity as well as coverage.

1.1 Book Structure

To facilitate a coherent understanding of cooperation for people working in the field as well as people acquainting ...