dm_decoder.m

By using a MATLAB program, design a Delta Modulation (DM) system with one step-size and a modified D

function [Sn]=dm_decoder(StepSize,fs, cn)
%fs: sampling frequency -> 捞固 林绢柳 signal阑 阂矾 坷搁辑 44.1Hz肺 瘤沥登绢 乐澜
%cn: received (encoded) signal.
%Sn: LPF 傈 reconstructed quantized signal 
%Sa: LPF甫 芭模 饶 弥辆 reconstructed signal 

xlen = length(cn);
Ts=1/fs;
n=0:Ts:Ts*(xlen-1);

%decoder and accumulator
xlen = length(cn);
accum(1) = 0;
for i=1:xlen
   if(cn(i)==0)
      accum(i+1) = accum(i)+StepSize;
   else
      accum(i+1) = accum(i)-StepSize;
   end
end

% quantized output
[xx,yy]=stairs(n,accum(2:xlen+1));
Sn=accum(2:xlen+1);