Efficient implementation of Nth-band FIR filters based on a simple window method

A simple method is proposed for designing Nth-band FIR filters with reduced hardware. This is achieved by making special use of the Kaiser window so that most of the filter coefficients will be related to each other by the simple relationship 1:2. Filter selection and design is simplified by means of data tables and a specially written selection program. Filter implementation both in PCM and delta modulation is proved advantageous compared with standard design methods