A Power-Efficient FFT Preprocessing Algorithm Utilizing Analysis Filter Bank

Abstract

With the development of high-speed sampling and real-time signal processing technologies, the power consumption for implementing large-point FFT operations is drastically increasing in application systems. This paper presents an FFT preprocessing algorithm based on a multi-channel analysis filter bank, which is implemented by an efficient multi-phase parallel structure. The operating frequency is reduced to fs/M for each constituent channel, while the spectrum width and the resolution are maintained. Meanwhile, the valid frequency point can be correctly identified and the resulting error is controlled below -30dB. Compared with the two-dimensional FFT algorithm, the power consumption accelerating factor can reach 2.4~4 by utilizing 4-channel analysis filter bank.