xngen.m

用dsp解压mp3程序的算法

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  xngen.m - Generating sinewave with noise in data file
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

N = 64;                     % file length
n = [0:N-1];                % time index
f = 500;                    % frequency = 500 Hz
fs = 8000;                  % sampling rate = 8000 Hz
omega = 2*pi*f/fs;          % frequency is 0.125 pi
x1n = 1200*sin(omega*n);    % sinewave amplitude A = 1200
x2n = (rand(1,N)-0.5).*400; % noise amplitude: -200 - 200
xn = round(x1n+x2n);        % rounding to near integer
fid = fopen('xn.dat','w');  % save signal to file xn.dat
fprintf(fid,'%4.0f\n',xn);  % in integer format
fclose(fid);