Generation of PN sequence and verification of randomness properties [Matlab]

Generation of PN sequence and verification of randomness properties [Matlab]

 

clc;

clear all;

len = input ('Enter the length of the sequence: ');

disp ('Generator Polynomial Example [1 0 0 1...1] ');

poly = input ('Enter the polynomial: ');

disp ('Initial state Example [1 0 0 1...0]');

ini = input ('Enter the initial state: ');

ff = log2(len+1);

%pn sequence generation

a = zeros(len,ff);

a(1,(1:ff)) = ini ;

for i = 1:(len-1)

x = 0;

for j = 2:(ff+1)

if (poly (1,j) == 1)

x = xor (x,a(i,(j-1)));

end

end

a ((i+1),1:ff) = circshift(a(i,1:ff),[0 1]);

a ((i+1),1) = x;

end

for i = 1:len

h(1,i) = a(i,ff);

end

fprintf ('The generated sequence is: \n');

disp (h);

%balance property

check = 0;

one = 0;

zero = 0;

for i = 1:len

if ( h(1,i) == 0)

zero= zero+1;

else

one = one+1;

end

end

disp ('BALANCE PROPERTY');

disp ('Number of ones: ');

disp (one);

disp ('Number of zeros: ');

disp (zero);

if ((one-zero) == 1)

fprintf ( 'Balance property is satisfied\n\n');

else

fprintf ( 'Balance property is not satisfied\n\n');

check = 2;

end

%autocorelation property

while (check == 0)

for i= 1:len

y(i,:) = xor (h,circshift(h,[0 i]));

end

for i = 1:len

one = 0;

zero = 0;

for j = 1:len

if ( y(i,j) == 0 );

zero = zero+1;

else

one = one+1;

end

end

z(i,1) = zero - one;

end

for i = 1: (len-1)

g(i,1) = -1;

end

g (len,1) = len;

disp ('AUTOCORRELATION PROPERTY');

disp (z);

t=1:1:(len);

plot(t,z);

if(z == g);

fprintf ( 'Auto correlation property is satisfied\n\n');

check = 3;

else

fprintf ( 'Auto correlation property is satisfied\n\n');

check = 2;

end

end

% run property

while( check == 3);

runs = ((len+1)/2);

u = ff;

r = zeros (1,u);

count = 1;

for i = 1:len-1

if (h(1,i) == h(1,i+1))

count = count+1;

else

r(1,count) = r(1,count)+1;

count = 1;

end

end

r(1,count) = r(1,count)+1;

s = zeros(1,u);

for i = 1:(u-1)

s(1,i) = runs / (2.^i) ;

end

s(1,u) = 1;

disp ('RUN PROPERTY');

fprintf ('Runs\t\t\t Run Length \n');

for i = 1:u

fprintf ('%d\t\t\t\t %d\n',r(1,i),i);

end

if (r == s)

fprintf ('Run Property is satisfied\n\n');

check = 4;

else

fprintf ('Run Property is not satisfied\n\n');

check = 2;

end

end

if (check == 2)

disp ('The given sequence is not a PN sequence');

else

disp ('The given sequence is a PN sequence');

end