Case Study: A WiMAX/WLAN/LTE Synthesizer

Providing an always-best-connected wireless access is not straightforward considering the landscape of wireless networks that exist today. Traditionally, wireless networks were mostly used for telecommunication and aimed to cover a wide area. These networks work well for voice calls and low bit rate applications but for higher bit rate applications, newer networks are finding their way into the market. However, some of these networks are optimized for mobility at the expense of a lower data rate such as LTE and somehow WiMAX, while others focus solely on higher bit rates at the expense of mobility such as WLAN. As a result, giving the user access to all this variety of networks through a single device will provide a wider range of scope to optimize parameters such as speed and cost depending on the current application combined with user preferences. With this vision in mind, this chapter aims to contribute to this convergence, by focusing on a subsystem of the wireless device itself, namely the frequency synthesizer. The wireless standards chosen for this implementation also fit within this vision. They include metropolitan/wide area networks such as WiMAX and LTE and local area networks such as WLAN. These standards are complementary and in normal applications the user is unlikely to use more than one of them at the same time such as is the case when they are combined with a personal area network such as Bluetooth.