Efficient Recursive IDFT Scheme for Complex-valued Signals in Tap-selective Maximum-likelihood Channel Estimation

Abstract

This paper presents several efficient, recursive inverse discrete Fourier transform (IDFT) schemes for complex-valued input data in tap-selective maximumlikelihood channel estimation; the results of their implementation are also presented. The proposed schemes employ only real-valued arithmetic, which reduces the number of required real multiplication operations in comparison with conventional IDFT approaches; however, the number of real additions increases significantly due to the sliding window scheme. The results show that the schemes can reduce the computational complexity and enhance flexibility when only several subsets of the IDFT output bins are required.