There are different angles from which this book contributes to the understanding of wireless communication systems from the perspective of a Software Defined Radio (SDR). A common theme in this text is that some concepts seem easier in time domain and some others are simpler in frequency domain, while their mathematical derivations reinforce the idea. It is fun to grasp a concept covering all three sides. Finally, using this same approach of time and frequency domains as well as mathematics, the book explains the logic behind the functionality of some GNU Radio blocks (e.g., Costas loop, band edge FLL, polyphase clock sync, MM clock recovery).