Efficient FPGA architecture to implement non-separable fast Fourier transform for image and video applications

Abstract

ABSTRACT Fast Fourier Transform (FFT) is widely used in image and video processing applications to convert the respective image or video frames into transform domain that is very helpful to extract the accurate features of that image or video frame for various real-time applications. In this paper, efficient non-separable 8-point FFT architecture (DIT-FFT) is proposed that is implemented on Spartan-6 (xc6slx45-3csg324) FPGA. The proposed architecture consists of Data Format Conversion, Addition, Subtraction, Multiplier Equivalent and D-FF blocks, respectively. The non-separable equations of 8-point DIT-FFT are derived from the respective Butterfly Diagram that is then implemented using basic logic gates, which optimises the hardware utilisations with the help of Complex Conjugate property. The constant multiplications present in the non-separable DIT-FFT equations are implemented through Adders and Shifters presents in Multiplier Equivalent block which further optimises the overall hardware utilisations. Moreover, the Q-format are used to increase the data accuracy of the architecture. The comparison results show that the proposed architecture is better than existing in different prospectives.