Software implementations of the FFT for OFDM systems

number: 
1628
English
Degree: 
Author: 
Laith Burhan Mohammed Taher Al-Nahas
Supervisor: 
Dr. Ihsan Al-Meshhedani
year: 
2005
Abstract:

Orthogonal Frequency Division Multiplexing (OFDM) is one of the most powerful signal multiplexing approaches of advanced communication systems. It serves as a basic building block in many existing and forthcoming communication standards. FFT/IFFT is one of the computationally intensive and power hungry blocks in an OFDM system. A large number of Fast Fourier Transform (FFT) algorithms have been developed over the years. The most promising of those are: Radix-2, Radix-4, and Fast Hartley Transform. Most of these algorithms have been developed for special purpose CPUs. With the rapid development of computer technology over the past few years, more CPU cycles per second are available now than before. This has allowed the use of these general purpose CPUs for many signal processing applications, of which the FFT is an integral part. Therefore there is a need to develop FFT algorithms on general purpose computers. Proposed architecture has been developed and a software in C++ language has been implemented for FFT algorithms to find the most efficient algorithm. To build a reliable OFDM system, efficient algorithms for computing FFTs has been developed. The algorithms have been tested and run successfully in different environments, to make sure of its validity and testing its software functionality, results have been obtained from each algorithm and comparisons were made from different points of view in order to make full analyses for each algorithm and to determine which the best one is.