Preface

Wireless communications have seen large growth in the last several years. The huge uptake rate of mobile phone technology, Wireless Local Area Networks (WLAN) and the exponen‐ tial growth of the Internet have resulted in an increased demand for new methods of obtain‐ ing high capacity wireless networks. All of the current communication systems have adopted digital technology. The wireless communication systems are expected to play a more important role in providing portable access to future information services. The de‐ mand for new services to support Internet and advanced video applications presents the key technical challenges, i.e., multimedia access requires high-bandwidth and low-latency net‐ work connections for many users, mobility requires adaptation to time varying channel con‐ ditions and portability imposes severe constraints on receiver size and power consumption. Physical limitations on wireless channels impose huge challenges on reliable communica‐ tion. Bandwidth limitations, propagation loss, noise and interference make the wireless channel a narrow pipe that does not readily accommodate rapid flow of data.

Thus, researchers aim to design systems that are suitable to operate in such channels, in or‐ der to have high performance quality of service. Also, the mobility of the communication systems requires further investigation to reduce the complexity and the power consumption of the receiver.

This book presents new techniques that improve the performance of the communication sys‐ tem used for transmission of digital data over time varying channels such as high frequency mobile channels. It aims to provide highlights of the current research in the field of wireless communication, and to offer a contribution to the recent advances in this field. The subjects discussed in this work are very valuable to any researcher in the communication field, not only to researchers in the wireless related areas. The six chapters cover a wide range of top‐ ics in wireless communication starting with evolutionary algorithms, the conventional and adaptive precoders design, ad hoc networks, optical communication, signal processing and interference alignments.

The editor would like to thank all of the authors for their valuable contributions in the area of wireless communications hoping that the book will be of great help to the readers.

> **Dr. Mutamed Khatib** Dean, College of Engineering and Technology Palestine Technical University – Kadoorie (PTU) Tul Karm, Palestine
