Comments on "Finite word-length effects of pipelined recursive digital filters" [and reply]

The author comments that it is generally inappropriate to use stochastic models for coefficient quantization errors in digital filters, as proposed by Chang and Bliss (see ibid., vol.42, p.1983-95, Aug. 1994), since the associated effects are deterministic and amenable to linear analysis. Chang et. al. reply that the statistical analysis of coefficient quantization noise in digital filters is a useful technique because it gives theoretical and practical results without resorting to lengthy case-by-case trials. The realization problem of digital filters can thus be simplified analytically by statistical approaches. Furthermore, statistical approaches have an advantage of supplying unified tools for round-off and coefficient quantization noise.