function output = demultiplexer(Data, Alpha);% demultiplexing the received signal% used in Experiment 7,  Communications system 4e: Simon Haykinblock_s = fix(length(Data)/2);output=zeros(2,block_s);for i = 1: block_s       Dataf(i) = Data(2*i-1);        if rem(i,2)>0             output(1,2*i) = Data(2*i);       else          output(2,2*i) = Data(2*i);       end           endfor i = 1: block_s      output(1,2*i-1) = Dataf(i);      output(2,2*i-1) = Dataf(Alpha(i));end