msequence.m

直扩通信的MATLAB仿真

% File  Msequence.m
function Sequence=MSequence(SF)
SFlog2=log2(SF);
if rem(SFlog2,1)~=0,error('SF must be an integer power of 2');end
switch SFlog2
    case 3
        R=3;instate=zeros(1,3);instate(R)=1;
        N=2^R-1;generator=[0 1 3];
    case 4
        R=4;instate=zeros(1,4);instate(R)=1;
        N=2^R-1;generator=[0 1 4];
    case 5
        R=5;instate=zeros(1,5);instate(R)=1;
        N=2^R-1;generator=[0 2 5];
    case 6
        R=6;instate=zeros(1,6);instate(R)=1;
        N=2^R-1;generator=[0 1 6];
    case 7
        R=7;instate=zeros(1,7);instate(R)=1;
        N=2^R-1;generator=[0 3 7];
    case 8
        R=8;instate=zeros(1,8);instate(R)=1;
        N=2^R-1;generator=[0 2 3 4 8];
    case 9
        R=9;instate=zeros(1,9);instate(R)=1;
        N=2^R-1;generator=[0 4 9];
    case 10
        R=10;instate=zeros(1,10);instate(R)=1;
        N=2^R-1;generator=[0 3 10];
    case 11
        R=11;instate=zeros(1,11);instate(R)=1;
        N=2^R-1;generator=[0 2 11];
    case 12
        R=12;instate=zeros(1,12);instate(R)=1;
        N=2^R-1;generator=[0 1 4 6 12];
    otherwise
        error('SF must be a power of 2,>= at 8 and <=2^12.')
end
[Sequence,Outstate]=LinearFeedbackShiftRegister(R,generator,instate,N);
Sequence=1-2*Sequence;
%End of function file.