Design of optimum high-order finite-wordlength digital FIR filters with linear phase

A novel iterative quantization procedure for the design of finite wordlength linear phase FIR filters of high order and minimum frequency domain error is proposed: a one by one increased number of filter coefficients is quantized where the augmented frequency domain error is re-minimized in each case. This new approach achieves a smaller frequency domain error than rounding of the optimal non-quantized coefficients. It is also successfully applied to the design of Lth band filters with minimum frequency domain error. FIR filters up to a filter order 1500 are designed. Keywords— Design of high order FIR filters, Constrained Least Squares (CLS) design, finite wordlength coefficients