spread_frequency.m

TD中扩频的链路级仿真 通过MATLAB实现

%产生括频信号，SF为扩频因子

function [user_code,sf_signal]=Spread_Frequency(SF,Send_Signal);
a=Send_Signal;
n=length(a);            %收到的比特数
% 产生SF位OVSF扩频码
q=1; o_1=zeros(1,1); o_1=[1];
q=2; ovsf1=zeros(q,q); ovsf1=[o_1,o_1;o_1,-o_1];
nn=log2(SF);
ovsf=zeros(SF,SF);
for ii=1:nn-1, 
    ovsf=[ovsf1,ovsf1;ovsf1,-ovsf1];
    ovsf1=ovsf;
end
ii=round(rand(1,1)*SF);
user_code=ovsf(ii,:);
%扩频
cc=zeros(1,SF*n);
for ii=1:n,
    for jj=1:SF
        cc((ii-1)*SF+jj)=a(ii);
    end
end
user_code1=zeros(1,SF*n);
for ii=1:n,
    for jj=1:SF,
        user_code1((ii-1)*SF+jj)=user_code(jj);
    end 
end
sf_signal=cc.*user_code1;