నైరూప్య

Implementation of Interpolation algorithm in FPGA for Fine Frequency Accuracy

A.K. Singh, Prof. K. Subba Rao

In today EW scenario the Radar features are getting advanced day by day. To intercept and analyse signals coming from such Radar, ESM receivers also should have modern and advanced features and techniques. There are many ESM Receivers developed/being developed based on Analog and Digital techniques to measure the intercepted Radar signal parameters. Frequency of the signal is one of the important basic parameter measured by ESM Receiver. Better frequency resolution and accuracy are desirable specifications of the receiver. Systems based on Digital Receiver are sampled signal systems. By means of the Fast Fourier Transform (FFT) algorithm, Frequencies of intercepted signals can be estimated from their locations in the discrete spectrum with a resolution depending on the number of points of FFT. But computational or other limitations often restrict the number of points, which correspondingly restricts the resolution of the estimate provided by the FFT. This paper brings out implementation of interpolation algorithm in FPGA for fine Frequency accuracy without increasing the FFT size.