basicseq.m

cmda仿真程序

% the basic codes from the generating poly from the book spread spectrum applications on commercial systems

function[code1, code2] = BasicSeq(m)

N = 2^m - 1;

sreg = [0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1]; % register for code 1

sreg2 = [0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1]; % register for code 2

code1 = zeros(1, N);

code2 = zeros(1, N);

switch m

    case 3

        for i=1:N

            code1(i) = sreg(m);

            first = mod(sreg(2) + sreg(3), 2);

            sreg = circshift(sreg, [0, 1]);

            sreg(1)=first;

            code2(i) = sreg2(m);

            first2 = mod(sreg2(1) + sreg2(3), 2);

            sreg2 = circshift(sreg2, [0, 1]);

            sreg2(1)=first2;

        end           

    case 5

        for i=1:N

            code1(i) = sreg(m);

            first = mod(sreg(3) + sreg(5), 2);

            sreg = circshift(sreg, [0, 1]);

            sreg(1)=first;

            code2(i) = sreg2(m);

            first2 = mod(sreg2(1) + sreg2(2) + sreg2(3) + sreg2(5), 2);

            sreg2 = circshift(sreg2, [0, 1]);

            sreg2(1)=first2;

        end 

    case 7

        for i=1:N

            code1(i) = sreg(m);

            first = mod(sreg(4) + sreg(7), 2);

            sreg = circshift(sreg, [0, 1]);

            sreg(1)=first;

            code2(i) = sreg2(m);

            first2 = mod(sreg2(4) + sreg2(5) + sreg2(6) + sreg2(7), 2);

            sreg2 = circshift(sreg2, [0, 1]);

            sreg2(1)=first2;

        end 

    case 8 

        for i=1:N

            code1(i) = sreg(m);

            first = mod(sreg(1) + sreg(2) + sreg(3) + sreg(6) + sreg(7) + sreg(8), 2);

            sreg = circshift(sreg, [0, 1]);

            sreg(1)=first;

            code2(i) = sreg2(m);

            first2 = mod(sreg2(1) + sreg2(2) + sreg2(7) + sreg2(8), 2);

            sreg2 = circshift(sreg2, [0, 1]);

            sreg2(1)=first2;

        end 

    case 9

        for i=1:N

            code1(i) = sreg(m);

            first = mod(sreg(5) + sreg(9), 2);

            sreg = circshift(sreg, [0, 1]);

            sreg(1)=first;

            code2(i) = sreg2(m);

            first2 = mod(sreg2(3) + sreg2(5) + sreg2(6) + sreg2(9), 2);

            sreg2 = circshift(sreg2, [0, 1]);

            sreg2(1)=first2;

        end 

    case 10

        for i=1:N

            code1(i) = sreg(m);

            first = mod(sreg(7) + sreg(10), 2);

            sreg = circshift(sreg, [0, 1]);

            sreg(1)=first;

            code2(i) = sreg2(m);

            first2 = mod(sreg2(2) + sreg2(7) + sreg2(8) + sreg2(10), 2);

            sreg2 = circshift(sreg2, [0, 1]);

            sreg2(1)=first2;

        end 

    case 11

        for i=1:N

            code1(i) = sreg(m);

            first = mod(sreg(9) + sreg(11), 2);

            sreg = circshift(sreg, [0, 1]);

            sreg(1)=first;

            code2(i) = sreg2(m);

            first2 = mod(sreg2(3) + sreg2(8) + sreg2(9) + sreg2(11), 2);

            sreg2 = circshift(sreg2, [0, 1]);

            sreg2(1)=first2;

        end 

end