Farrow structure based Digital Decimator for Fractional Rate Sample Conversion using Lagrange Polynomial

The concept of decimation plays very important role in the modern digital communication systems. Digital decimators or decimation filters are used to decrease the sampling rate of a sampled signal in digital domain. The Farrow Structure provides an efficient way to implement the decimation filter using polynomial approximation method for arbitrary sample rate change which offers the option of continuously adjustable resample ratio. In this paper, Lagrange polynomial approximation method has been used to implement Farrow structure based decimator. The optimum filter coefficients have been calculated using Lagrange Polynomials. Simulation results have been presented.