Toolbox for the design of IIR digital filters
Henri Leich · 2002
In this paper, we describe a complete toolbox for the design of IIR filters. The first problem to be solved is the approximation problem which is developed for simultaneous approximation of the attenuation and the group-delay. The result is the transfer function for the direct or cascade form. The second step is the quantization of the coefficients for a fixed-point arithmetic. This done for the two structures by means of a sensitivity function followed by an exact computation. The third point is to compute the scaling factors and the noise performances of the different structures (direct, transposed and immediate) with internal or external scaling factors. This toolbox can also be used to quantize the coefficients in a discrete space. At the end of the procedure, the IIR digital filter can be implemented on a fixed-point DSP, in a FPGA or in an ASIC.