Split-radix FFT pruning for OFDM based Cognitive Radio system

Abstract

It is necessary to devise the efficient FFT algorithm which can reduce computational complexity due to multiplication in the butterfly with twiddle factors in the OFDM based Cognitive Radio, where zero valued inputs/outputs outnumber nonzero inputs/outputs. Now Transformed Decomposition is considered as more suitable candidate than FFT pruning method for OFDM based Cognitive Radio due to the feasibility of HW design about irregular position of zero inputs/outputs. However, expecting that the efficient HW design methodology is available later, the split-radix FFT pruning algorithm is proposed for getting the more reduction of computational complexity. Through analyzing and comparing the computation complexity about the split-radix FFT pruning algorithm and other algorithms, it was shown that the proposed method is more efficient than other conventional algorithms in computational complexity.