How to convert between real and complex IQ signals
This article shows how to convert from real-valued radio signals to complex IQ signals and back with some example code in Python. Introduction to real …
Category: SDR Basics
Introduction to RF Signal Classification
RF signal classification deals with the task of analyzing unknown signals. The goal is to automatically classify the unknown signal into some predefined categories. In …
High Resolution Time-Frequency Representations for RF Signals
Time-frequency representations are used to analyze time-varying signals with respect to their spectral contents over time. Apart from the commonly used short-time Fourier transform, advanced …
Basics of Analog-to-Digital Conversion
Sampling and Quantization Every SDR receiver uses at some stage an analog-to-digital converter (A/D converter or ADC), that transforms an analog signal to a digital …
The Direct Sampling SDR Architecture
The traditional radio receiver uses analog processing, i.e. analog mixers, filters and amplifiers to convert the incoming RF analog signal from the antenna to baseband, …
SSB Demodulation
The demodulation of single-sideband (SSB) signals requires special attention, because simple mixing leads to superposition of the upper and lower sidebands at audio frequencies. The …
Powerful Hardware for SDR: The Zynq and the Zedboard
This an excerpt of my more extensive paper on Xilinx’s Zynq System-on-Chip for Software Defined Radio processing from 2018: “The Xilinx Zynq: A Modern System …
Advantages of Digital Signal Processing for SDRs
With the advent of digital technology, analog circuits in radio transceivers have been widely replaced by digital signal processing. This is because digital signal processing …