Hi,
I recently triy to receive ibeacon signal whose modulation scheme is
GFSK,
so I use the /gfsk_demod/ block in gnuradio and succeed to demodulate
ibeacon signal. Yet I don’t understand the meaning of some of its
parameters
and why these parameters are assigned to some certain values. For
example,
the parameter /gain_mu/ is set to 0.175 as default.
I then read the codes of /gfsk_demod/ and find that there is actually
one
step of clock recovery there. Then I read the papers cited by the
documentation of /gfsk_demod/ block and learn the principle of the
digital
clock recovery algorithm used in it.
As far as I know, the Mueller and Muller algorithm uses linear
combination
of samples to estimate the timing error, which is then used to adjust
the
sampling phase. So the parameter /omega/ is the estimate of timing shift
caused by carrier frequency shift, the parameter /mu/ is the estimate of
final timing shift, and /gain_omega/ and /gain_mu/ are weights of
estimate
of timing error when adjust respective parameters, is it correct?
Then the last question is how are these parameters assigned? For
example,
/gain_mu/ is set to be 0.175 and /gain_omega/ is set to be
0.25*/gain_mu/*/gain_mu/. Are these assignment related to any previous
works
or derivatives or some experiments or simulations? Do these values have
any
special meaning?
Thanks,
Kun Q.
–
View this message in context:
http://gnuradio.4.n7.nabble.com/How-are-parameters-of-gfsk-demod-block-assigned-tp49734.html
Sent from the GnuRadio mailing list archive at Nabble.com.