function alpha = kaiser_alpha(req_psll)% KAISER_ALPHA returns the alpha parameter that gives the required input% PSLL.% % Taken from C code of Gerhard Heinzel:% % Compute the parameter alpha of Kaiser windows% from the required PSLL [dB]. Best-fit polynomial% was obtained from 180 data points between alpha=1% and alpha=9.95. Maximum error is 0.05 % Maximum error for PSLL > 30 dB is 0.02% % M Hewitson 19-05-07% % $Id: kaiser_alpha.m,v 1.2 2011/04/08 08:56:36 hewitson Exp $% a0 = -0.0821377;a1 = 4.71469;a2 = -0.493285;a3 = 0.0889732;x = req_psll / 100;alpha = (((((a3 * x) + a2) * x) + a1) * x + a0);% END