Table 2-9: Substitutions in the Digital Example
Modification of Process
|
Modifications in the Code in Simple Digital Modulation Example
|
Set the carrier signal's initial phase to phase, measured in radians
| y = dmodce(x,Fd,[Fs phase],'psk',M);
z = ddemodce(y,Fd,[Fs phase],'psk',M);
|
Use a low-pass filter after demodulating but before demapping. num and den are row vectors that give the coefficients, in descending order, of the numerator and denominator of the filter's transfer function.
| z = ddemodce(y,Fd,Fs,'psk',M,num,den);
(See also Filter Design Issues if you plan to use filters.)
|
(ASK only) Use a Costas phase-locked loop
| y = dmodce(x,Fd,Fs,'ask',M);
z = ddemodce(y,Fd,Fs,'ask/costas',M);
|
(FSK only) Use noncoherent demodulation
| y = dmodce(x,Fd,Fs,'fsk',M);
z = ddemodce(y,Fd,Fs,'fsk/noncoherence',M);
|
