Introduction to Wireless System Design

4Software‐Defined Radio

4.1 Introduction

Wireless communication has evolved significantly, starting with radio transmissions, and progressing to cell phones and modern smartphones. Software‐defined radio (SDR) offers advantages such as flexibility, upgradability, and reconfigurability. SDR relies on digital signal processing (DSP) algorithms, reducing the need for analog hardware. It improves reliability, enhances spectrum utilization, and finds applications in various domains. An overview of SDR is provided, highlighting its advantages over conventional radio systems. The underlying concepts and architecture of SDR are examined, including direct synthesis for compact implementation. Key building blocks, such as the antenna, RF front‐end, and analog‐to‐digital and digital‐to‐analog converters (ADCs and DACs), are explored.

A deeper look is taken into the individual building blocks, discussing their functionalities and design considerations. The utilization of software‐defined antennas (SDAs) to leverage SDR capabilities is discussed, along with the importance of the RF front‐end in signal transmission and reception. The vital process of analog‐to‐digital and digital‐to‐analog conversion is explored, bridging the gap between the analog and digital domains. The digital front‐end (DFE) plays a pivotal role in SDR systems as it performs functions such as Sample Rate Conversion (SRC) for synchronization, Channelization for dividing bandwidth, Digital Up Conversion (DUC) for transmission, ...