пятница, 29 апреля 2011 г.

OFDM, COFDM: CIS-79, conditionaly name TANDEME

CIS-79, conditionaly name TANDEME
Ch-79, QAM-64, Sh-37.5, Br~30.476, k = 59/256
OFDM, COFDM

The signal is here. Send by YuriVR.

Author: SergUA6 
Band Width ~3000 Hz
Low Range ~350 Hz
Baud Rate ~30.476 Hz
n-Ary (PSK/MPSK) QAM-64 and PSK-8
Count of Carriers 79
Step between carriers 37.5 Hz
RX mode SSB

Sonograms:

pic.1 Generall view





 pic.2 Normal symbol and destroyed by distortions symbol



Diagrams:

pic.3 The constellation in the special/service channeles


pic.4 Full constellation of the channel







CIS-79, TANDEME - Russian native signal, which full analysis was realized by participants of  "power group"  of our forum. From singularities it is necessary to mark a preamble. This preamble isn't OFDM part, and represents an independent special fragment. Also usage in service channels of modulation PSK-8 is curious enough. The record completely corresponds to initial parameters of the signal, and thereupon rather explicitly can be studied in SA without special problems. Despite high quality of the material, there are destroyed symbols, which as are perfectly visible at the detailed review in SA, it is the result of an overload at signal's recording.