Chapter 1: Wireless Communications and Transceivers - an Overview

Yichuang Sun

1.1 Wireless and mobile communications

Wireless and mobile communications is one of the fastest growing areas of modern life. It has an enormous impact on almost every aspect of our daily lives. A world of ubiquitous wireless devices is emerging, from wireless sensors and tags to mobile terminals. There are a number of wireless systems and networks in operation such as GSM, GPRS, EDGE, IS-95, UMTS, IMT2000, DECT, IEEE 802.11, and Bluetooth, and several multiple access techniques including MC-CDMA, W-CDMA, and OFDM are used. Future-generation wireless communication, networking and connectivity beyond the so-called 3G have already attracted international attention.

Mobile cellular communications, wireless LANs and broadband wireless access are the three most popular application areas. Long-range cellular communication encompasses the evolution of GSM (2G+: GPRS, EDGE), IS-95 and 3G systems (IMT2000/UMTS). It aims to achieve full mobility and global roaming for individual links maximising system capacity. In short-range wireless networking and wireless connectivity, WLAN or PAN covers local hot spot areas for very high data rate asymmetric individual links (e.g. IEEE 802.11, HIPERLAN), and universal wireless networking and home connectivity are now achieved by Bluetooth and DECT. Fixed wireless local loops provide wireless access from street kerb to home for broadband internet and multimedia services. Space-time coding and ultra-wideband modulation have stood out particularly as the hope for future wireless and mobile communication systems.

The future wireless and mobile communication system will be universal, suitable for different wireless networks such as the W-CDMA-based cellular mobile system, OFDM-based wireless LANs and inexpensive Bluetooth. The mobile terminal or transceiver in such a universal system must be reconfigurable to meet multiband and multimode requirements and must be of small size and low power to drive the cost down. This book concerns itself with this important subject.