Further information :-
I am running 15.625Hz Wide GMSK The frequency shift is half the bit
rate.
Here I include some quotes.
Gaussian Minimum Shift Keying, or to give it its full title Gaussian
filtered Minimum Shift Keying, GMSK, is a form of modulation used in
a variety of digital radio communications systems. It has advantages
of being able to carry digital modulation while still using the
spectrum efficiently.
GMSK modulation is based on MSK, which is itself a form of
continuous-phase frequency-shift keying. One of the problems with
standard forms of PSK is that sidebands extend out from the carrier.
To overcome this, MSK and its derivative GMSK can be used.
There are several advantages to the use of GMSK
modulation for a radio communications system. One is obviously the
improved spectral efficiency when compared to other phase shift
keyed modes.
(PSK31 for instance although this mode is also using Varicode).
It is immune to amplitude variations and therefore more resilient
to noise, than some other forms of modulation. A further advantage
of GMSK is that it can be amplified by a non-linear amplifier and
remain undistorted.
Eddie G3ZJO
On 14/03/2013 16:01, g3zjo wrote:
Running GMSK Beacon now on 476.100KHz
GMSK Is in MMVari Software.
Non decoded reports of my signal welcome.
73 Eddie G3ZJO
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