ABSTRACT
Mobile worldwide interoperability for microwave access (WiMAX) promises to deliver high data rates over extensive areas to high user densities. The latest development of WiMAX provides both multiple-input multiple-output (MIMO) and multihop relay. However, there are major concerns including leveraging high data rates and large cellular coverage in network planning to compete with other beyond 3G networks. For mobile WiMAX to be successful, it must achieve high spectral efficiency and large coverage using limited available spectrum for system optimization. This chapter gives a technical overview and presents design strategies to achieve highly efficient mobileWiMAX. Directional distributed relaying is introduced for effective multiuser transmission. Furthermore, channelmeasurements are performed and analyzed for a multihop relay inmobileWiMAX. Practical applications are also investigatedwithin a realistic urban environment through ray-tracing techniques.
There are two major technological and social trends significantly changing people’s lives: wireless communications and the Internet. Leveraging these two trends, worldwide interoperability for microwave access (WiMAX) creates a new utility enabling the development of new services and new Internet business models. In particular, the full potential of WiMAX will be realized when it is used for innovative nomadic and mobile broadband applications [1]. With the finalization of the IEEE 802.16e standard [2] and upcoming test and certification ofWiMAX products [3], mobile broadband services are becoming a reality. The 802.16e standard provides broadbandwireless Internet Protocol (IP) access to support a variety of services (such as voice, data, and multimedia) on virtually any device. The operation ofWiMAX is currently limited to a number of licensed frequency bands below 6 GHz for reliably supporting non-line-of-sight (NLoS) operations. The 802.16e standard has also become a part of the IMT-2000 family.
