createpulsefilter.m

来自「这是一个关于完成QAM调制的Matlab示例程序」· M 代码 · 共 22 行

function [pulseFilt,delay] = CreatePulseFilter(fs,fd)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% This is a utility function that creates the pulse shaping filter.
% The filter is assumed to have a group delay of 3 symbol periods,
% it's region of support is therefore 6 symbol periods, symmetrical
% about it's center.  The rolloff factor, beta, is assumed to be 0.5.
%
% fs = sampling frequency
% fd = symbol frequency
% pulseFilt = fir coefficients
% delay = group delay given in number of symbol periods
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

delay = 3;
r = 0.5;

pulseFilt = rcosine(fd,fs, 'fir/sqrt',r,delay);
pulseFilt = pulseFilt/(sqrt(pulseFilt*pulseFilt'));

return