SA update to the version 6.2.5.3

SA update to the version v 6.2.5.2/3 

Current update though doesn't affect the main SA possibilities, nevertheless solves a range of problems. 

The first and bad enough problem, is connected with imaging/mapping of the correlative triangle (CT) in OFDM module. I underline only with imaging. 

At the usual revision of the algorithms and their decisions, mathematic had confused us with the news, that the correlative triangle left side can't be good/correct/rightly, as there is no general root at words "rightly" and "left". :-) 

The joke had been estimated, but nevertheless, really, at the very early beginning of OFDM module development, an output of image CT on the screen was unrolled/turn on 180 degrees concerning a vertical axis. And the right (good/correct/rightly) side CT has appeared on the monitor as the left side. As it doesn't influence results of operation of the algorithm, the error in display wasn't so noticable and had been existing long time enough. 

In this version we recover justice as it doesn't demand any fundamental changes in the main mathematical calculations. 

Actually such awkward situation is gross enough error, although it doesn't influence the general results. 
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We remove historically added restrictions on the lower bound of filters in WF module and the general-purpose/universal demodulator. In the current version the general approach to a filtration is reconsidered, and the range of setting of frequency of a cutoff of filters is accepted from 1 to Fd/2 a Hertz. 

It allows to solve, in some cases, the analysis tasks more effectively. 


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It is possible to set any, in limits from 1 to 1000 level/step of time gating in VMW module, at the usage of a stroboscopic output of the image, in this version. 

It as expands VMW module possibilities to the better side. 


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The error in ISD corrector operation is eliminated, we were informed about this error by users. The corrector incorrectly worked in many cases, it had been connected with update of the algorithm of correction in version 6.2.4.6 the Error was thin enough, and to find it out casually was rather problematic: that once again shows, that users are very attentive and skilled in analysis questions. 


In this version, besides bug fixing, speed of ISD corrector operation ISD was increased approximately in one and a half-two time, and its efficiency is raised. Thus as before, the algorithm isn't omnipotent, but it is general-purpose/universal, and it still can be mistaken, but in the majority of practical cases, it is well enough compensates various, not fatal distortions of signals. 


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In all previous versions, attempt to load the files with big size and big sampling rate in VMW module, leaded to an exceptional situation (error). Sampling rate reduction In some cases helps, but in general, it does not solve the problem. In version 6.2.5.3 this moment is corrected. 

Record-example the size of record ~ 10 mbytes. 


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Also possibility to synthesize various MFSK signals has been added into OCG programm, al though it doesn't affect SA, nevertheless, we recieved requests to include this function into synthesizer, so we realized it it in version OCG 1.2.1.2 The result of synthesis of signal MFSK-11 is shown below. 

As usual, a range of small, hardly noticeable improvings had been done, and some minor problems were solved. 


Good Luck~

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.

SA update to version v 6.2.5.0/1

SA update to version v 6.2.5.0/1

Planned SA update.

Determination of an exact amount of frequencies in the various MFSK signals is an important enough task in the analysis. In this update we had added this possibility, we introduced function "Count freqs” into the module of viewer of the form(WF).

The function "Count freqs" calculations of the size of the grid of frequencies. I underline, not an amount of frequencies used/involved in a current fragment of a signal, but dimensionality of the grid, in which limits these frequencies are generated.

Basic actions on function "Count freqs" usage are the following:

1. To receive speed of manipulation of the signal - Baud rate, by any method. It is desirable, but not a mandatory step.

2. To select the signal by H-markers. This operation demands an accuracy. It is impossible to select the signal too densely, and it is impossible to select it too widely, the reasonable compromise is required. Normally we recommend to allocate the markers on distance within (1.5-3) *Br from the signal.

3. Call the Phase detector function. It is the standard operation, which creates the new window with results.

4. It is necessary to call WF module in the new window through PopUp menu, it is also the standard action. If in the first point value Baud rate has been received, in WF module, then the automatic filtration of the signal will be produced, otherwise the filtration will be necessary to realize in the manual mode.

5. It is necessary that all artifacts (usually it is the beginning and the end of a signal) have been displayed behind the display window in WF module. It is possible to reach, at least by two methods:
The first - to select a pure part of the signal with V-markers, and to create a copy in the new window.
The second - using horizontal zoom, and shifting/moving the signal by the horizontal slider, to bring in the artefacts behind the window borders.

6. To turn on the mapping of the histogram "Sum"=ON on the "pure" signal. To pick up the size of the histogram by vertical. To install H-markers on the upper and lower channel of the histogram. To cause PopUp menu of the module. Position of V-markers can be any as all visible part of the signal is processed.

7. To select point "Count freqs".

Important! The result of function "Count freqs" is not an amount of channels in the signal, but the size of the uniform/proportional grid of frequencies, in which the used channels are "laid down". The so-called grid of formation, the size of this grid represents big interest in the analysis.

Range of determination of dimensionality of the grid of frequencies by the function "Count freqs", is from 4 to approximately 260. In reality, the function defines grids of more dimensionalities to 300-320, but it very strongly depends on the signal quality, and many other things.

Error report appearance is possible.

The reasons/causes:

- Both H-markers, and-or one of them, are installed not on the histogram lines/channels
- There are lesser then 4 or more then 400 frequencies in the signal
- The distance between H-markers is too small, or the markers are combined
- the function can't be completed correctly at current parameters of the signal, or on the current fragment of the signal.

There is an article on usage of this new function, as there are some thin moments and nuances, which are beyond the update description => Signals Analysis in SA version v 6.2.5.1

It is necessary to show certain care, although function "Count freqs" works reliably enough in many cases, nevertheless, it is rigid enough algorithm which can be mistaken.

As usual, minor problems found out by users are removed. Also I want to express gratitude to all beta testers, who have taken part in preliminary testing of this update.

Good Luck~