function y = mod_mfsk_020530b (x,n,M)

%figure (12) ; %clear;
global k Fc Fd Fs n Fs_n;

Tone = Fd ;

% FSK2 Modulation Procedure
    
if M == 2
    y = cos( 2*pi* (Fc-Tone/2 + Tone*x) .*n );   % -Fd, +Fd
end

if M == 4
    y = cos( 2*pi* (Fc-3*Tone/2 + Tone*x) .*n ); % +- 1,3 Fd
end