14 December 2016

unid FSK 200Bd/400


Yet another unidentified, and unknown to me, FSK waveform copied on 12424.8 KHz (cf) at 0808 UTC. Key parameters are 200 Baud as manipulation speed and shift of 400 Hz (Fig. 1). These values match one of the possible ARQ-E3 settings but decoding does not produce outputs so the signal doesn't belong to such waveforms family.
This same signal is reported in radioscanner.ru forum, you may read the topic and get more info here.

Fig. 1
As a side notes, its spectum has a characteristic pattern (Fig. 2) and working on the period length it's possible to get the value of 896 bit which is likely the frame structure (Fig. 3). Unless erorrs, the frame consists of 56-bit  of known symbols (sync and  ) and 840-bit room allocated for unknwon symbols (data block). 

Fig. 2
Fig. 3

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