Overview

In this chapter, design examples of wireless mobile receiver and transmitter systems are introduced. These design examples are used to explaine how to use the methods and formulas discussed in previous chapters for the receiver and transmitter designs and what the most important considerations in practical designs are. A complete design of a mobile communication transceiver is also involved. Here only the critical parameters such as sensitivity, intermodulation spurious attenuation, and adjacent channel selectivity in the receiver side, and modulation accuracy, ACPR, and noise/spurious emissions in the transmitter side are discussed since they basically characterize the RF performance of a mobile transceiver. The design targets of these parameters are specified, and how to achieve these targets in design are described in detail.

Two transceiver system-design examples are presented in following sections. A multimode and multiband superheterodyne transceiver design, which actually covers the designs of GSM, TDMA, AMPS and GPRS (general package radio system) mobile systems, is first discussed. Then a CDMA transceiver is designed based on the direct conversion architecture as the second example.

6.1. Multimode and Multiband Superheterodyne Transceiver

In this section, the RF system design of a mobile RF transceiver which can operate in the GSM (GPRS), TDMA, and AMPS systems and in the 800 MHz cellular and 1900 MHz PCS dual bands is described in detail. At present, some GSM mobile stations not only have GPRS function but also support EDGE (enhanced data rates for global evolution). In this example, the EDGE...