Design of FFT processor using low power Vedic multiplier for wireless communication

Digital Signal Processing (DSP) is a very significant and active research area. High throughput is a requirement for most wireless communication systems. The critical bottleneck that affects communication ability is the Fast Fourier Transform (FFT), which is the essence of most modulators. Currently, Floating point FFT processors have been used in Radar signal processing, fast convolution, Spectrum estimation and OFDM based modulators/demodulators. Efficient VLSI based architectures are required for real-time FFT processing. The multiplication limits the performance in terms of throughput of FFT. Consequently, there is a need for high speed and low power multiplier architectures with minor truncation error. The present paper presents a modified binary floating-point multiplier using Vedic mathematics and a modification in the previously published Vedic multiplier circuit has been proposed. The entire design has been implemented in Verilog HDL. Synthesis and simulations are done using Xilinx ISE Design Suite 14.5.The performance evaluation in terms of speed and area occupied is compared with the previously reported Vedic multiplier architectures. Using 90 nm technologies, the Power Delay Product (PDF) of the proposed Vedic multiplier gets reduced through KSA by 86.41% compared to the multipliers. The Vedic adder power is reduced by 45.9% when it is compared with the carry look-ahead adder. The overall power delay product is reduced around 55-60% through the FFT processor by using Vedic mathematics.