3G Handset and Network Design

CHAPTER 3

3G Handset Hardware

In the two previous chapters we identified that one of the principal design objectives in a cellular phone is to reduce component count, component complexity, and cost, and at the same time improve functionality. By functionality we mean dynamic range—that is, the range of operating conditions over which the phone will function—and the ability to support multiple simultaneous channels per user. We showed how GPRS could be implemented to provide a limited amount of bandwidth on demand and how GPRS could be configured to deliver, to a limited extent, a number of parallel channels, such as simultaneous voice and data. However, we also highlighted the additional cost and complexity that bandwidth on demand and multiple slots (multiple per user channel streams) introduced into a GSM or TDMA phone.

Getting Started

The general idea of a 3G air interface—IMT2000DS, TC, or MC—is to move the process of delivering sensitivity, selectivity, and stability from RF to baseband, saving on RF component count, RF component complexity, and cost, and increasing the channel selectivity available to individual users. You could, for example, support multiple channel streams by having multiple RF transceivers in a handset, but this would be expensive and tricky to implement, because too many RF frequencies would be mixing together in too small a space.

Our starting point is to review how the IMT2000DS air interface delivers sensitivity, selectivity, and stability, along with ...