Performance analysis of improved dynamic kernel function in fast Fourier transform

An improved dynamic kernel function Fast Fourier Transform (FFT) with variable truncation scheme (VTS) is proposed, wherein the dynamic kernel function deploys a twiddle factor fixed-point numerical representation, and substitutes simple shift-and-add operations for the FFT multipliers, accomplishing a hardware resource saving. Using Xilinx System Generator, the improved dynamic truncation function can yield at 20% average reduction on the hardware resources. The proposed VTS dynamically scales the result of every stage in FFT and maximally uses the word length in FFT without complicated design additions. The proposed VTS also can detect weak signal compared to the method of only truncating the least significant bit (LSB).