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

                                                                

          Here is example of VDL-2. Sent by foregin collegues.

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.

SECAM - National standard of Russian TV

Full TV spectrum, with NICAM (digital audio channel)

SECAM - National standard of  Russian TV 

Author: SergUA6 

Band Width ~ 7 mHz

RX mode Source I/Q record

The signal is here. Send by geka. The file size is about 10 Mb.

Sonograms:

pic.1 General view

pic.2 The detalization

pic.3 The graphical spectrum

Diagrams:

pic.4 NICAM - digital channel of sound

Pictures:

pic.5 Channel of the brightness after AM detector in VMW 

SECAM - National standard of Russian TV - The television standard of Russia. Standard SECAM is well described in the literature, so there is no special sence to stop on it. The interest represents an additional digital sound channel by technology NICAM, in which modulation  PSK-4 (QPSK) is used. This additional channel, is allocated apparently from screenshots, between chrominance subcarriers and the main analog channel of the soundtrack.

PSK: CIS-3000

CIS-3000

PSK-8, Br-3000.

PSK

The record of this signal is here. Send by RadioKoteg.

Author: SergUA6

Band Width ~3400 Hz

Low Range ~600 Hz, in this example only!

Baud Rate 3000 Hz

n-Ary (PSK/MPSK) PSK-8

Carrier frequency ~2313 Hz, in this example only!

ACF Preamble ~ 85 ms

RX mode SSB

Sonograms

pic.1 Generall view

pic.2 General structure of the signal

Diagrams:

pic.3 8th harmonic

Pictures:

pic. 4 Phase constellation

pic.5 ACF preambles

CIS-3000 - With very high probability this signal has the Russian origin roots. More and more often there are signals which are leaving the limits of standard phone channel. This signal represents that kind of signals. The spectrum of this signal occupies 3400 Hertz. The maximum technical speed 3*3000 = 9000 bps.

SATCOM Satellite, US INTEL - 260.41, UHF (B)PSK-2, Br - 260.41

SATCOM Satellite, US INTEL - 260.41, UHF

(B)PSK-2, Br - 260.41

Here is the signal. Send by RSCAN.

Author: SergUA6

Band Width ~520 Hz

Baud Rate 260.47 Hz in this example, exact value 260.41

n-Ary (PSK/MPSK) (B)PSK-2

ACF ~1900 ms preamble, ~368 ms data/message

RX mode SSB

Sonograms:

pic.1 General view

Diagrams:

pic.2 General structure of the signal

pic.3 Phase constellation

Illustrations:

pic.4 ACF

SATCOM Satellite, US INTEL - 260.41, UHF - is the very wide spread signal, which can be met in the channeles of satellite group SATCOM. This signal is encrypted.

PSK: INMARSAT Satellite

INMARSAT Satellite

INMARSAT AERO. OQPSK, Br-10500

The perfect example of INMARSAT AERO, send by RadioKoteg.

Author: SergUA6

Band Width ~10500 Hz

Low Range ~750 Hz, in this example only!

Baud Rate 10500 Hz

n-Ary (PSK/MPSK) OQPSK, constellation looks as square PSK-8

Count of Carriers single mode

Carrier frequency 6079 Hz, in this example only!

ACF 500 ms

RX mode SSB

Sonograms:

pic.1 Generall view

pic.2 Baud rate

Diagrams:

pic.3 Typical characteristics of OQPSK and other half-modes.

pic.4 ACF

pic.5 View of the signal in VMW

Pictures:

pic.6 Phase constellations

INMARSAT AERO - INMARSAT is using wide enought line of different protocols. In this record, it is presumably AERO-H. The signal is very bright. All the parameteres of this signal can be easily determined.

PSK:TETRA - DMO, terminal to terminal connection

TETRA - DMO, terminal to terminal connection

Direct Mode Operation, Br-18000, pi/4 DQPSK

Perfect example of TETRA-DMO signal, send by geka.

Author: SergUA6

Band Width ~25000-26000 Hz

Baud Rate 18000 Hz

n-Ary (PSK/MPSK) pi/4 DQPSK

Carrier frequency 15639 Hz, in this example only!

RX mode source I/Q record

Sonograms:

pic.1 Generall view

pic. Manipulation speed

pic.3 Getting of carrier frequency

Diagrams:

pic.4 Generall frame structure

Pictures:

pic.5 Constellation

TETRA - DMO, terminal to terminal connection - the mode of direct terminal (mobile stations, phones etc) connection of TETRA standard, without participation of base stations equipment.

PSK: SATCOM Satellite, Telemetry, UHF

SATCOM Satellite, Telemetry, UHF

PSK-2, Br-1200, 15 Channels of data + 1 Synchro

Sample record of SATCOM, Telemetry, UHF, Send by sea2000

The bit stream converted into wav file, for view in VMW

Author: SergUA6

Band Width ~2000-2100 Hz

Low Range ~1452 Hz, only for this record!

Baud Rate General 1200 Hz

n-Ary (PSK/MPSK) 2

Carrier frequency ~2523 Hz, only for this record!

RX mode SSB

Sonograms

pic.1 General view

pic.2 Manipulation speed

Diagrams

pic.3 Phase constellation

Pictures:

pic.4 The bit stream structure in VMW

SATCOM Satellite, Telemetry - Telemetry of sattelites of SATCOM series. The signal has standard parametres. Transmission of 16 channels is organised transparently enough . The structure is well visible on pic.4

Data of all channels is transferred continuously-consistently by ring (circle), without cunnings. That is why, it is enough to build up the bit stream in 16bit "column" after demodulation, to find 0th sinchronization channel on characteristic sequence, and it becomes possible to receive a bit stream of any channel with a binding to its(channel) number. Transmission speed in the channel is 75 Hz.

As it is visible from pic.4, in the signal, in channeles 2, 9, 11-15 only bit=1 are transffered, in other channeles the data is transferred.

The bit stream in channels assumes further processing. Crypto security is not eliminated, and most likely it presents.

Signals. PSK: Tetra

TETRA

Professional digital trunking system, pi/4 DQPSK

1) Tetra. The record send by ponder_.

2) Another good example of Tetra signal. Send by sergo2007.

Author: SergUA6

Band Width ~ 22000 Hz

Low Range ~ 2000 Hz, shift is possible, acception in SSB

Baud Rate 18000 Hz

n-Ary (PSK/MPSK) PSK-8, pi/4 DQPSK

Carrier frequency ~ 13242 Hz, shift is possible, acception in SSB

ACF ~56-57 and 14 ms

RX mode SSB

Sonograms:

pic.1 Generall view

pic.2 the signal in 4th exponantion

pic.3 the signal in 8th exponantion

Diagrams:

pic.4 manipulation speed

pic.5 Phase constellation

pic.5 ACF after PSK demodulator

TETRA - is the standard called to replace analogue systems of type PMR on VHF range. It was established approximately in 1995. From the point of view of a signal, it is easily enough recognised under the basic characteristics, such are speed of manipulation 18000 Hz and individual ACF. It is necessary to notice that, despite wide enough prevalence, there are almost no good records of this type of signals, because relvatively wideband strips IF and AF bands are required, altought we have two records with this signal, with good quality.

Signal : Clover 2000

Clover 2000
Clover 16p4a, mixed PSK-16 manipulation and four-lever AM at the same time

Author: SergUA6 6.0
Band Width ~ 2000 Hz
Low Range 500 Hz
Baud Rate 62.5 Гц, in the channel
n-Ary (PSK/MPSK) PSK-16
Count of Carriers 8 spectral bands with not crossed spectrum
Step between carriers 250 Hz between carriers of the channels
RX mode SSB

The very qualitative sample of Clover 2000

Sonograms:

pic.1 General view

Diagrams:

pic.2 Graphical spectrum

Pictures:

pic.3 Phase constellation

pic.4 Crossings in constellation

This signal is from Clover family of signals. It is rare enough signal on the air. For definition of parametres of the channel, it it is necessary preliminary to select it. The constellaions, which are represented in the description, concerned to the lower channel by the spectrum.

Usage of the mixed modulation, allows to increase speed in the channel, for this variant it turns out (if I'm not mistaken) 6*62.5=375 bit per second on the channel, the common speed is 3000 bps. That is not bad characteristic, at the 2000Hz band on HF.