www.gusucode.com > 基于matlab的2PSK的系统仿真 > 基于matlab的2PSK的系统仿真/lpf.m
% 用到的低通滤波器函数 function [t,st]=lpf(f,sf,B) %This function filter an input data using a lowpass filter %Inputs: f: frequency samples % sf: input data spectrum samples % B: lowpass's bandwidth with a rectangle lowpass %Outputs: t: time samples % st: output data's time samples df = f(2)-f(1); T = 1/df; hf = zeros(1,length(f)); %全零矩阵 bf = [-floor( B/df ): floor( B/df )] + floor( length(f)/2 ); hf(bf)=1; yf=hf.*sf; [t,st]=F2T(f,yf); st = real(st);