gardner.m

采用LBG算法计算矢量量化器的Matlab仿真程序。

clc
clf
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
fd=1;
fs=80;
delay=2;
r=1;
num=100;
SNR=20;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%产生随机信息，以及对信息进行曼彻斯特编码
source=zeros(1,2*num);
for i=1:num
    if randn<0
        source(2*i-1)=1;
        source(2*i)=-1;
    else
        source(2*i-1)=-1;
        source(2*i)=1;
    end
end
%source=ones(1,num*2);
%source(2:2:end)=-1;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%波形成型
[yg,tt]=rcosine(fd,fs,'sqrt',r,delay);
data1=rcosflt(source,fd,fs,'filter',yg);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%经过AWGN信道
E=1;
sgma=sqrt(E/(2*10^(SNR/10)));
noise=randn(length(data1),1)*sgma;
data2=data1+noise;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%匹配滤波
data3=rcosflt(data1,fd,fs,'filter/Fs',yg);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%同步模块
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
off=13;
tol=0;
sample=zeros(1,length(data3)*fd/fs);
temp=0;
for flag=1:length(data3)*fd/fs-1
    sample1=data3((flag-1)*fs/fd+off);
    sample2=data3((flag-1+1/2)*fs/fd+off);
    error=(sample2-temp)*sample1;
    if abs(error)>tol 
    if error<0
        off=off+1;
    elseif error>0
        off=off-1;
    end
    end
    temp=sample2;
    sample(flag)=sample2;
end
stem(sample);