Design And Analysis Of RF Subsystem Of Mobile Handset In Cellular Wireless Location System

The main topics of this paper are RF circuits designing process and the selection of RF parameters. Discussions are targeted especially at how to improve the performance of transceiver and frequency synthesizer, and at how to make the handset's RF module best compatible with various technical requirements in wireless location system.Nowadays, with the non-stopping advancements in RF technology, the wireless communication networks are capable of carrying more and more services. As shown in this paper, the wireless location system is based on a cellular network with four base stations. Handsets and base stations communicate through direct sequence spectrum spreading channel, and location the handsets are precisely estimated by U-TDOA technology. Such systems are already installed and utilized in several cities around the world (2006, in Shanghai). The circuits studied in this paper are part of RF module of the mobile handset working in wireless location system.There are several kinds of structures for the transceiver. Here, in order to obtain robust performance, we use super heterodyne receiver and indirect frequency conversion transmitter. According to the initiatives of software radio, AD and DA conversions are performed in IF part, then the RF part could get simplified. As for receiver, sensitivity, dynamic range, and noise factor are the major performance indices. While for transmitter we should pay the most attention on radiated power.Frequency synthesizer, as the transceiver's heart, is a very important element. Its stability and phase noise standard may directly affect the overall performance of the system. In the paper, after doing comprehensive research on up/down link's requirements and transceiver's major performance indices, a qualified system designing scheme is presented at last.