vsbpf.m

通信中一些基本实验的程序AM、FM、ASK、FSK、PSK等等

function [t,st]=vsbpf(f,sf,B1,B2,fc)
%This function filter an input by an residual bandpass filter
%inputs:f:frequency samples
%       sf:input data spectrum samples
%       B1:residual bandwidth
%       B2:highest freq of the baseband signal
%Outputs:t:time samples
%        st:output data's time samples
df=f(2)-f(1);
T=1/df;
hf=zeros(1,length(f));
bf1=[floor((fc-B1)/df):floor((fc+B1)/df)];
bf2=[floor((fc+B1)/df)+1:floor((fc+B2)/df)];

f1=bf1+floor(length(f)/2);
f2=bf2+floor(length(f)/2);
stepf=1/length(f1);
hf(f1)=0:stepf:1-stepf;
hf(f2)=1;

f3=-bf1+floor(length(f)/2);
f4=-bf2+floor(length(f)/2);
hf(f3)=0:stepf:(1-stepf);
hf(f4)=1;
yf=hf.*sf;
[t,st]=F2T(f,yf);
st=real(st);