RF and IF Digitization in Radio Receivers: Theory, Concepts, and Examples

摘要

Hardware development of analog-to-digital converters (ADC's) and digital signalprocessors, including specialized integrated circuits, has advanced rapidly within the last few years. These advances have paved the way for development of radio receivers using digitization at the IF and in some cases at the RF. Applications for these receivers are expected to increase rapidly in areas such as cellular mobile, satellite, and personal communications services (PCS) Systems. The constraints place on these receivers due to hardware limitations of these devices are investigated in this paper. Some examples of state-of-the-art ADC's, signal processors, and specialized integrated circuits are listed. Various quantization techniques, nonlinear compression devices, postdigitization algorithms for improving dynamic range, sampling downconverters, and specialized integrated circuits are discussed as they are expected to be useful in the development of these types of receivers. Several examples of radio receivers employing digitization at the IF and RF are also presented.