darshkamal
Junior Member level 1

In a packet based comm system using GFSK as a modulation scheme, I want to check for the alternating preamble every 2 bits (0,1 or 1,0), so that if not found drop these 2 bits and check in the next 2
This check isn't done in the base band, but at the IF stage. I need to do it over the IF carrier(400k), i.e. I want to know the info the carrier hold is preamble or other data.
FYI, bit rate = 5k and sampling rate = 26M
My idea was to count the number of carrier zero-crossings per bit for 0 and 1 case, but there isn't a significant difference between both of them in this low bit rate(The difference is error and noise-prone)
Can any one help ?
Thanks in advance
This check isn't done in the base band, but at the IF stage. I need to do it over the IF carrier(400k), i.e. I want to know the info the carrier hold is preamble or other data.
FYI, bit rate = 5k and sampling rate = 26M
My idea was to count the number of carrier zero-crossings per bit for 0 and 1 case, but there isn't a significant difference between both of them in this low bit rate(The difference is error and noise-prone)
Can any one help ?
Thanks in advance