BPSK vs. GMSK
Mon, 2 Feb 1998 08:21:05 -0800
>BPSK is robust but not very spectrum efficient. When you start with only a
>couple kHz, that's an important consideration. GMSK and some variants
>don't have this problem.
Theoretically speaking MSK (or GMSK) should give 6dB performance
over BPSK but only using coherent demodulation, which is much more
to do than in case with BPSK, that is why most if not all existing MSK
receivers use non-coherent decoding which introduces 10 dB loss in SNR.
I am currently working on algorithm for real time coherent BPSK decoding
using DSP board from Analog Devices and it almost (not quite really)
33 MOPS processor to its limits. MSK will require to increase software
complexity about 4 times, but I will be willing to try it.
73 de Sergei KD6CJI