Here is a YouTube video about Phil Harman VK6PH on Direct Fourier Conversion - An alternative architecture for SDRs, and is part of a growing collection of videos I have found to be useful. The reason is noting with the availability of low cost and high performance Graphics Processing Units (GPUs) an alternative architecture can be used that has a number of advantages over the current DDC approach and understanding science related to software defined radio.
This tutorial, "Phil Harman VK6PH on Direct Fourier Conversion - An alternative architecture for SDRs" is free education you can watch, which will help you deepen your knowledge and be better prepared for licence exams, schoolwork, or operating radio equipment.