Millimeter-wave Radio over Fiber System for Broadband Wireless Communication

The wireless networking has attracted much interest in past decades, owing to its high mobility. People can connect their devices such as PDAs, mobile phones or computers to a network by radio signals anywhere in home, garden or office without the need for wires. The global growth of mobile subscribers is much faster than wireline ones, as the Figure 1 shows (Yungsoo et al., 2003). The number of mobile subscribers worldwide has increased from 215 million in 1997 to 946 million (15.5% of global population) in 2001. It is predicted that by the year 2010 there will be 1,700 million terrestrial mobile subscribers worldwide. At present, main wireless standards are Wireless LAN (WLAN), IEEE802.11a/b/g, offering up to 54-Mbps and operating at 2.4-GHz and 5-GHz, and 3-G mobile networks, IMT2000/UMTS, offering up to 2-Mbps and operating around 2-GHz. But with the development of human society, people have higher requirements for the services, such as video, multimedia and other new value-added services. In order to offer these broadband services, wireless systems will need to offer higher data transmission capacities.