engen.m

用dsp解压mp3程序的算法

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%    engen.m - This program generates "e(n)" data file
%              for simulating digital phase-locked loop
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

n = [0:1023];                 % generate 1024 samples
omega = 0.02*pi;              % assume f=80 Hz, fs=8000 Hz
e1n = 1200*sin(omega*n);      % sinewave with amplitude A=1200
e2n = (rand(1,1024)-0.5).*600;% random noise with amplitude: 
                              % -300 -> 300
en = e1n+e2n+2047;            % sinewave+random noise
                              % set mean = 2047
en(208) = en(208)+1220;       % add some impulse noise samples
en(380) = en(380)+1399;
en(620) = en(620)+698;
en(800) = en(800)+1538;
ren = round(en);              % round to near integer
fid = fopen('en.dat','w');
fprintf(fid,'%4.0f\n',ren);   % save down signal to file xn.dat
fclose(fid);
plot(n,ren);
xlabel('Time index n'); ylabel('Amplitude');
title('Simulated noisy e(n)');
axis([0 1023 -inf inf]);