Computing partial DFT for comb spectrum evaluation
- 1 June 1996
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Signal Processing Letters
- Vol. 3 (6), 173-175
- https://doi.org/10.1109/97.503281
Abstract
A comb spectrum evaluation problem arises in the (de)modulation for orthogonal frequency division multiplexing-based (OFDM-based) multichannel communication system. Efficient algorithms for this special type of partial discrete Fourier transform (DFT) computation are studied. For an M-component comb spectrum evaluation with transform length N, it is shown that only O(N+MlogM) multiplications are needed, compared with O(NlogM) multiplications necessary for a narrowband spectrum evaluation. Pruning radix-2 decimation-in-time fast Fourier transform (FFT) requires only (N/4+M/2log/sub 2/M-M) nontrivial complex multiplications. The frequency shift technique has also been applied to allow a modularized mixed-radix structure for the computation of comb spectrum with an initial component not starting from zero frequency point.Keywords
This publication has 4 references indexed in Scilit:
- Efficient computation of the DFT with only a subset of input or output pointsIEEE Transactions on Signal Processing, 1993
- Pruning the decimation-in-time FFT algorithm with frequency shiftIEEE Transactions on Acoustics, Speech, and Signal Processing, 1986
- Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division MultiplexingIEEE Transactions on Communications, 1985
- Pruning the decimation in-time FFT algorithmIEEE Transactions on Acoustics, Speech, and Signal Processing, 1976