понедельник, 13 февраля 2012 г.

PSK: VDL-2 (VHF) - AirSystem, PSK-8, Br - 10500

VDL-2 (VHF)
AirSystem, PSK-8, Br - 10500

Author: SergUA6 
Band Width ~17000 Hz
Baud Rate 10500 Hz
n-Ary (PSK/MPSK) PSK-8
RX mode source I/Q record
                                                                



Sonograms:

pic.1 General view


pic.2 Manipulation speed


Pictures
pic.3 Phase constellation





VDL-2 - It is rather new and the perspective view of aviation telecommunication (ATN). It is very actively introduced in practice. It is provided step-by-step change/move from the previous generation of similar system ACARS, to the new VDL-2, VDL-3. As well as in ACARS, data exchange between aircrafts and the earth occurs by extremely short packages. In average, lenght of the package is about 20-40 мс, but it can be both shorter and longer packages. In comparison with ACARS, the throughput of channel ATN in VDL-2 is essentialy increased from 2400 bps (ACARS) to ~31500 bps.


As a whole, at appropriate quality, the signal is confidently enough analyzed and identified, there are no obvious features detected.