function y = synth_QFM(n, m)
%  y=synth_QFM(n, m) - quasi FM complex
% n is harmonic order of carrier, m is modulation index

global sr;	% sampling rate
D = 0.1; 	% s - duration
f	= 2000;	% Hz - carrier frequency

f0 = f/n;

x = abscissa(D);

y = 0.5 * m * sin(2 * pi * (n-1) * f0 * x) + ...
	sin(2 * pi * n * f0 * x) + ...
	0.5 * m * sin(2 * pi * (n+1) * f0 * x);