Abstract: Methods and apparatuses are provided for a fast Fourier transform (FFT)/inverse fast Fourier transform (IFFT) architecture that not only allows for efficient computation of N-point FFT/IFFT transform (N=2n), but also allows for efficient reuse of the multipliers and delay blocks for efficient implementation of signal energy detection and autocorrelation of length or period 2p, where p?{0, 1, . . . , log2(N)?1}. Signal energy detection and autocorrelation may then used for received energy measurement, frame synchronization, including packet detection or symbol timing, and carrier frequency offset estimation.