how to perform FFT on multivalued bit string?

hi,

i have a bit string of size 560*1 of values 0 and 1 and some cells contains both 0 and 1 values.. now, i need to apply FFT on this bit string.. to do so, first i need to convert cell values to double values by making use of Cell2mat function (bcz FFT function can be applied on double values only).. so, i used cell2mat function and i applied fft on it... i got wrong results... i.e., if a cell in bit string contains [0,1] ,then after using cell2mat function the values 0 and 1 are being splitted and size of bit string is being increased...

code for binary string :

new_len = 576;
old_len = length(a);
mapped_index = 1 + mod((1:old_len) - 1, new_len);
b = accumarray( mapped_index(:), a(:), [new_len 1], @(L) {unique(L.')} ) .';
B1=cell2mat(b);
 b2=B1';

i got error: undefined function fft for input arguments of type cell...

Can anyone help me with this..

Answer 1

[Walter Roberson]

"Can anyone help me with this.."

No. There is no defined meaning for taking the fft of a many-to-one mapping.

Taking the Discrete Fourier Transform (fft) of a bit-string is questionable itself.

Are you working on the paper http://www.sciencedirect.com/science/article/pii/S2090447912000895 ?