FINITE WORD LENGTH ANALYSIS OF THE RADIX-22 FFT

In this paper, we analyze the quantization error effects of the radix-22 FFT algorithm. We propose per tone models for the error power. This is a different approach from the com-mon choice of a maximum or mean value over the spectrum. In particular, we treat three different errors: 1) due to input quantization, 2) due to coefficient quantization and 3) due to quantization after a multiplication. This analysis is applied to a DMT scheme. Simulation results agree with the theoretical predictions. 1