Realisation of nonrecursive delta-modulation filters using look-up tables

A look-up table realisation method for nonrecursive delta-modulation filters is described. The filtering process is optimal in the sense that it minimises the quantisation error due to the filtering operations. Several filter configurations based on this method are proposed. Any filtering behaviour can be achieved by the same filter network changing only the ROM contents, provided that the number of the filter coefficients does not exceed a maximum. Experimental results confirm the theoretical predictions.