APPENDIX B Evaluation of FIR Design Error Minimization Let's minimize the expression where Error ¼ x ¼ Ð p Àp jxðoÞj 2 do x(o) ¼ D(o) ­ H(o) D(o) ¼ desired frequency response X C i e Àjok ¼ actual frequency response HðoÞ ¼ i¼À1 to 1 We start by setting the derivative of the error x with respect to the filter coefficients (the one parameter that we have control over and want to optimize) equal to zero: djxj=dC i ¼ 0 Ð p Ã