My project is based on audio watermarking with time spread echo method. For this I have generated PN sequence and for encoding the following formula is applied h(n)= d(n)+ alpha*p(n-delta)
where d(n)= dirac delta function, alpha= amplitude of PN sequence, p(n)= PN sequence, delta= time delay.
here I know that p(n) is an array of PN sequence. I have done the coding for dirac delta function and also generated PN sequence but i am unable to write code for p(n-delta) as mentioned in above formula. I tried the following code: delta=0.001; for x=1:1023 temporary = PN1(1,x); new_index =(x-delta); PN1(1,new_index) = temporary; end disp(PN1); f=alpha*(PN1-delta);
but by this i always get the error mentioning that 'Attempted to access PN1(1,0.999); index must be a positive integer or logical'.
So i request to plz help me out to do time shifting in PN sequence. Plz provide code of the above mentioned formula.
Best Answer