Chapter 3: A Reconfigurable Baseband Chain for 3G Wireless Receivers

Md. Iqbal Younus, Anup Savla, Arun Ravindran, Mohammed Ismail

3.1 Introduction

The rapid growth of wireless communications has led to the proliferation of different standards. The highly competitive market demands low cost, low power and small form-factor devices. Convergence of voice, data and video, evolving standards and a high demand for new features as they are invented, all require equipment vendors to build systems that are flexible and field upgradeable [1]. In such an environment where requirements are rapidly changing, the time it takes to bring new products to market can spell the difference between success and failure. Vendors need an approach that allows them to quickly design, debug and verify their systems. This chapter discusses modular 3G baseband building blocks with a focus on the design of a reconfigurable baseband chain that precedes the analogue-to-digital converter (ADC) in a multistandard fully integrated wireless receiver. The circuits proposed here retain flexibility and simplicity of design, and all are based on one active element. Using these circuits, adigitally reconfigurable base band chain is implemented. Thebaseband chain is adapted to accommodate GSM, IS-95, and WCDMA wireless standards. The proposed approach enables the development of highly programmable, flexible and upgradeable baseband circuits with a short design cycle.