This book is a detailed and applicable medium designed for the purpose of helping students and researchers to understand the Fourier Transform theory in signal processing. Fourier Transform (FT) is a field of processing which has shown significant growth in the last few decades. Every book on signal processing discusses its various uses. This book also stresses on Fourier Transform theory and its utilization in signal processing methods. The book contains topics like DFT, FFT, OFDM, evaluation methods and image processing programs. Through this book, we aim at providing an overview on this phenomenon along with references and incentives to push students forward for in-depth research in this field and also, present methods for practical usage. This book mainly focuses on electrical engineers, communication engineers, signal processing engineers and mathematicians as it provides practical based overview on signal processing.