A high-throughput memory-based FFT/IFFT processor for OFDM systems

This study presents a high-throughput memory-based Fast Fourier Transform/Inverse Fast Fourier Transform processor for Orthogonal Frequency Division Multiplexing systems. Modified single-path delay feedback processor is proposed. Compare to original multi-path delay commutator processor, not only the area and power consumption can be reduced, also whole system is easy to dominate. Besides, this new method of calculating twiddle factor decreases the complex coefficients and reduces the ROM usage significantly. Using parallel single-path delay feedback with mixed-radix FFT processor increases the processing speed and achieves the continuity of data throughput. The design is mainly a comparison with multi-path delay commutator processor and single-path delay feedback processor utilizing the base memory method. Introduce the TSMC 0.18um standard cell library; we achieve a 128 point FFT/IFFT processor with high throughput. The operating frequency is up to 50MHz. Besides, the design can be applied to 3GPP LTE and IEEE 802.16e in 1.25MHz bandwidth.