CROWD-36 (SERDOLIK) - OFDM mode

CROWD-36(SERDOLIK) - OFDM mode

Ch-34, Br-40, Sh-40, PSK-4, The OFDM without CP

Author: SergUA6 

Band Width ~1400 Hz

Baud Rate 40 Hz

n-Ary (PSK/MPSK) PSK-4

Count of Carriers 34

Step between carriers 40 Hz

Pilot tone(s) 393 Hz, this tone or pilot, or continue transmit data of zero in PSK-4 mode

RX mode SSB

The example of CROWD-36 (SERDOLIK) OFDM MODE

Sonograms:

pic.1 General view

pic.2 Manipulation speed

pic.3 Detalization of the second channel

 Diagrams:

pic.4 The first channel in the fourth degree

 pic.5 Constellation of the first channel

CROWD-36 (SERDOLIK) - OFDM mode - is curious enough signal, where the principles of OFDM technologies usage  for formation of a various type of manipulations/modulations are perfectly shown. 


MFSK and OFDM segments are generated/formed absolutely equally, the difference is only in the form of used modulation, besides this OFDM signal has no cyclical prefix. Speed of manipulation is precisely equal to frequency space (step between frequencies) - that is the big rarity, and it is possibly linked with the fact, that initial synchronization is provided on the operation stage in MFSK a mode. 


The presence of pilot-tone or the continuous transmission of zero in PSK-4 mode is viewed In the second channel of OFDM segment, alghough i can't say definitely.


Though OFDM signals without CP  are very difficult for the analysis, in this record  it is even possible to define a manipulation mode in the first (lower) channel thus this channel is rather easily possible to select/mark this channel confidently enough, thanking presence of the pilot-tone in the second channel. 


Absence of the prefix allows to use as much as possible densely all the spectrum, with the maximum real speed that in this signal makes 34*40*2=2720 bps. If the second channel is really the pilot, then the maximum technical speed is slightly less - 2640 bps.

MFSK: CROWD-36 (SERDOLIK)

CROWD-36(SERDOLIK)

MFSK-34, Br-40, Sh-40, Ch-34

Author: SergUA6 

Band Width ~1400 Hz

Baud Rate 40 Hz

Count of Carriers 34 manipulation frequency

Step between carriers 40 Hz

RX mode SSB

An excellent example of CROWD36 (SERDOLIK) MFSK. Send by Ware.

Sonograms:

pic.1 General view at the different spectrum resolution.

pic.2 Manipulation speed

Diagrams:

pic.3 Allocation and quantity of the frequencies

pic.4 demodulation in SA

CROWD-36(SERDOLIK) MFSK From the different sources, it is used by various diplomatic services of the CIS countries, Russia is defined in general easily enough. Spacing is 40, speed 40, frequencies 34.Alghough it is necessary to manage to count the frequencies, because to do it on the spectrum it not so that easy. ;) The number "36" in the name of the signal is the mystery for me. I haven't ever seen 36 frequencies, so I may suppose that 36 frequencies are very seldom used or quantity of frequencies does not play a role in the name of the signal. 
Speed of manipulation in chat-mode makes 10 hertz.  Mazielka 2 tone and it is possible Mazielka 6 tones are Very closely connected with Crowd-36.

OFDM, COFDM: DRM+ (DRM-E)

DRM+ (DRM-E)

Ch - 213, PSK-4, Br - 400 Hz, Sh - 444.4(4) Hz, k = 1/9

Author: SergUA6 

Band Width ~95500 Hz

Baud Rate 400 Hz

n-Ary (PSK/MPSK) PSK-4

Count of Carriers 213

Step between carriers 444.4(4) Hz

ACF      100 ms

RX mode Source I/Q record

The excellent example of DRM+. Thanks to IK1YDE.

Sonograms:

pic.1 General view

pic.2 The main signal's parameters.

Diagrams:

pic.3 The constellation in the channel

pic.4 Detalization

Pictures:

pic.5 ACF of the signal.

DRM+(DRM-E) - DRM format for VHF broadcasting, it is intended to extrude the analogue decisions in this sphere. It posseses range of attractive advantages: the necessary band is about 95-96 kHz on the broadcast channel, the transmission till 4 of independed programs is possible in one channel.


The signal itself is the typical representative of OFDM tecnology. All the parameters are defined in SA easyly enough. The maximum technical speed for PSK-4 and 213 channeles is 170 kbit/sec. In reality, the real speed of data transmission is a bit lower (about 130-150 kbit/sec), at the expencse of usage of part of the channels and symbols as the pilot/service.


As far as i know, the prespective of this standard in Russia are *foggy* enough, this record sent by collegues from Europe.

SA update to versionv 6.2.6.3

SA update to version v 6.2.6.3 

This is the planned SA update.

In this version support of Drag-and-Drop function is added.

The function of detection/determinition of the offset modes of the phase manipulation is introduced in the Phase viewer. 

It is necessary to show certain care, as any automatic system of identification, this function can be mistaken, especially on the signals, which are damaged by various distortions. Nevertheless in some cases, the presence of this automatization is justified. 


Also a number of minor errors found out by users is corrected.

~ Good Luck

Scrambler: Hagelin HC-256, HF

Hagelin HC-256, HF
Analogue dynamical synchronized scrambler.

Author: SergUA6 
Band Width  ~3000 Hz
Low Range  ~300 Hz
RX mode  SSB
 

The signal is here. Send by Angstrem.

Sonorgam

pic.1

HAGELIN HC-256, HF - the analogue dynamical synchronized scramler. It sounds like "Pinocchio" :-).

The features of this signal: the preamble is the same as two-channeles FSK-2 with the parameters ( look pic.1). There are short synchro-bursts also every ~400 ms  (look pic.1). 

Update SA to version 6.2.6.0

Update SA to version 6.2.6.0

This is planned update SA.

Added possibility insert the saved path to the file/directory. This is really handy because sometimes a very long way, and clicking on directories rather tedious, easier to insert from the clipboard.

Added the possibility of fast increase in the desired part of the signal in the WF module. Fragment between V-markers scaled over the entire window.

Function of oversampling uses parallel computing, in general, it increases the speed and quality.

 

Quality resampling improved by revising the algorithm and its optimization.

The examples old and current solutions.

Extreme caution should be taken with to any external processing program. As minimum all need thorough inspection and testing, otherwise You may experience various unpleasant incidents, such as this one.

SA provides accuracy of 1 Hz resampling at sampling rates up to 100 MHz.

In fact, precision in 1 Hz is not a fundamental limitation, and the internal procedures of SA uses precision oversampling in fractional values SR, if needs.

In the OFDM module, function of "Find CT" also uses parallel computing.
 

As well as the usual fixed various minor problems.

Good Luck.

OFDM, COFDM: DVB-T (Digital Video Broadcasting — Terrestrial)

DVB-T (Digital Video Broadcasting — Terrestrial)

Ch-1705, QAM-16, Br~2232, Sh~2790, k=1/4 (not standard/typical mode - 4K)

Author: SergUA6 

Band Width ~4800000 Hz

Baud Rate ~2232 Hz

n-Ary (PSK/MPSK) QAM-16

Count of Carriers 1705

Step between carriers ~2790 Hz

RX mode direct output from modulator

The signal is here. Send by horizon.

Sonograms:

pic.1 General view

Diagrams:

pic.2 Quantity of the chanells, manipulation speed

pic.3 Constellation in the channel

pic.4 Constellation in the channel

DVB-T(Digital Video Broadcasting — Terrestrial) - The digital standard of the television, which wide spread all over the world has begun long time ago. In Russia implementation of this standard is carried out since 2004.


This example is received from modulator DVB-MidiMod2 — 2×TS it possesses not absolutely standard parameters. The standard modes for DVB-T modes are 8K and 2K, with a standard band of a signal approximately 7600 kHz. 8K and 2K are the sizes FFT/IFFT blocks, which are used at modulation/demodulation, where K = 1024. In this example the size of the block is not typical for DVB-T - it is equal 4K. 1K, 2K, 4K etc - this are the typified values oriented on usage of the fast algorithms FFT, which hardware implementation is well mastered. Nevertheless, within the limits of coefficient k = 1/4 for this signal, there is a big set of other, absolutely correct sizes of FFT blocks, at which the signal modulation/demodulation is possible, as it is shown. The signal has mass of distinctive features, to enumerate which there is no sense. 
Standard DVB-T itself is well documentated and pretty difficult. 


From explicit features of this signal, it is possible to mark offset/shift of the central channel of the constellation, what is most likely is a consequence of malfunction of the modulator. At total quantity of channels in 1705, loss of one, certainly isn't a fatal problem as in standard DVB-T powerful noise-resistant coding is used. It is necessary to mark that in 2007, the new standard DVB-T2, which had been accepted, possessing considerably more ample opportunities than DVB-T.