Definition and Components of SDR
Overview of SDR
Software-Defined Radio (SDR) is a wireless communication system that relies on software-based components and offers reconfigurability, enabling flexible processing and conversion of digital signals. Compared to traditional radio communication systems, SDR stands out due to its high degree of flexibility and versatility, making it a key technology in connecting our increasingly wireless world.
System Architecture
A typical SDR system consists of two core parts: the analog front-end and the digital back-end. The analog front-end handles transmission and reception functions of the radio communication system, while the digital back-end is responsible for executing complex signal processing tasks. Furthermore, high-bandwidth SDR platforms are designed to operate over a wide frequency range, often spanning from DC to 18 GHz.
Signal Processing
In an SDR system, signals in the analog domain are first processed by the front-end, while the back-end handles digital signal processing. Analog-to-Digital Converters (ADCs) and Digital-to-Analog Converters (DACs) serve as bridges between these two domains, converting signals between analog and digital forms. The digital back-end typically employs Field-Programmable Gate Arrays (FPGAs), which utilize reconfigurable logic gates to implement diverse functions. FPGAs are also equipped with extensive onboard digital processing capabilities, such as modulation, demodulation, upconversion, and downconversion. This flexibility in the digital back-end allows new algorithms and protocols to be easily integrated without requiring changes to the existing hardware.
