Comments on "FIR digital filter design techniques using weighted Chebyshev approximation"

The history of the FIR filter approximation problem, as recently presented by Rabiner, McClellan, and Parks, is deficient in some areas and misleading in others. Some corrections are suggested. In addition to a brief discussion of different approaches to the design of FIR digital filters, areas into which present methods can be readily extended are outlined. The relationship between the parks and McClellan method and the upper and lower function method is presented.