Efficient IFFT architecture design for OFDM applications

In this paper, to reduce the memory size of inverse Fourier transform (IFFT) for OFDM-based applications, we propose a new IFFT design technique based on a signed integer mapping of three IFFT input signals: modulated data, pilot and null signals. The proposed method focuses on reducing the size of memory cells in the first two stages of the single-path delay feedback (SDF) IFFT architectures since the first two stages require 75% of the overall memory cells. By Synopsys simulation of the first two stages of IFFT, it is shown that the proposed method achieves about 77.7% reduction in area compared with the conventional method, and about 36.9% reduction compared with CIM method.