Digital Signal Processing in Radio Receivers and Transmitters

The interface between analog and digital signal processing paths in radio receivers and transmitters is steadily migrating toward the antenna as engineers learn to combine the unique attributes and capabilities of DSP with those of traditional communication system designs to achieve system s with superior and broadened capabilities while reducing system cost. Digital signal processing (DSP) techniques are rapidly being applied to many signal conditioning and signal processing tasks traditionally performed by analog components and subsystems in RF communication receivers and transmitters [1±4]. The incentive to replace analog implementations of signal processing functions with DSP-based processing includes reduced cost, enhanced performance, improved reliability, ease of manufacturing and maintenance, and operating ̄ exibility and con® gurability [5]. Technologies that facilitate cost-effective DSP-based implementation s include a very large market base supporting high-performan ce programm able signal processing chips [6], ® eld program mable gate arrays (FPGA), application-speci® c integrated circuits (ASICs), and high-performan ce analog-to-digital and digital-to-analog converters (ADC and DAC respectively) [7]. The optimum point for inserting DSP in a signal processing chain is determ ined by matching the system performance requirements to bandwidth and signal-to-noise ratio (i.e., speed and precision) limitations of the signal processors and the signal converters. In this paper we review how clever algorithm ic structures interact with DSP hardware to extend the range and performance of DSP-based processing in RF transmitters and receivers.