Mf. Fahmy et al., DESIGN OF FIXED-POINT STATE-SPACE DIGITAL-FILTERS WITH LOW ROUND-OFF NOISE, International journal of circuit theory and applications, 22(1), 1994, pp. 3-13
A simple method is described for the design of fixed-point recursive d
igital filters with low round-off noise. The method is based on reduci
ng to zero as many as possible of the coefficients of the filter state
matrices. An optimization procedure is used to get the optimum value
of linear transformation that minimizes the total output round-off noi
se power. Compared with the existing approaches, this method is charac
terized by its computational simplicity, very low output round-off noi
se (if not the lowest possible) and low coefficient sensitivity. The s
tructure of the proposed technique is modular, which makes it suitable
for VLSI implementation. The technique is then employed to obtain a r
educed-order low-round-off-noise filter with characteristics equivalen
t to some desired FIR specifications. Illustrative examples are given
to verify these advantages.