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.

Update SA to the version v 6.2.5.8 : implementing technology of parallel computings

Update SA to the version v 6.2.5.8 

Planned SA update. 

At the desire of users, in this version support of 8bit data in unsigned and signed formats is added. The unsigned format is typical for the standard wav files, signed format for the various exterior devices, programs and calculators. 

Also, since this version, we are implementing technology of parallel computings. It allows to double, quadruple etc. speed of the main operations, depending on an amount of cores in the processor. 


The maximum quantity of CPU cores supported by SA is equal 8, it is not the principle limitation, simply we have considered that it will be enough for beginning , and if composition CPU includes 16 cores or more, SA won't use all of them, but SA will try to involve all accessible cores to 8 inclusively. 

On the current moment, the functions of the main working window are already parallelized. The screenshot above, shows: 


- Red color - means already parallelized operations 
- Green color - means not parallelized operations, but very strongly optimized 
- Not selected by any colour - means it is left "as is" yet. 


It is the initial stage of increasing of SA computing power, further gradually, we will translate/turn whenever possible, all functions of the program in this parallel mode. 


Though this version already had preliminary and careful beta testing, some errors are still possible, which will be corrected in the process of their detection. 


Good Luck~

Updating SA to the version v 6.2.5.4.

Updating SA to the version v 6.2.5.4.

This is planned update SA. We had added function of inversion of the whole spectrum at once. This function, in difference from regular procedure, works much more quickly. Very often similar problems arise at the analysis of various I/Q (SDR) records.

At coincidence/combination of H-markers and a call of the regular procedure of in-band inversion, the special case of fast inversion of the whole spectrum is working.


 ***
 two popular enough in analysis functions ACF and CCF are introduced into module WF. Basically, it duplicates similar decisions in the basic working window, but for the module of the form of a signal, this opportunity is far not superfluous.

Please pay attention, that the result of ACF function is displayed in the new window.

The result of function CCF is mapped in the same window, whence the function has been caused. Thus, the basic signal is mapped as a background, and the working element of the window is function CCF, its graphic is scaled, displaced, etc. the Segment/fragment of a signal, which is chosen as example for calculation CCF, is painted in yellow color.


*** 
The work with long symbols (up to 32000 samples (LS) and higher) is provided in module OFDM. The previous versions had restriction in 9000-10000 samples. However, it is necessary to notice, that analysis of OFDM signals with such sizes LS (~ 16000-20000 samples), demands certain, sometimes essential expenses of time.


As usual, a number of internal small (sometimes even funny) bugs, which had been found out by users are eliminated. To a category of the "funny bugs", we bringh a recent turn of image CT, in this version all is returned on former positions.:-) actually, both variants are correct. But as, the left part at us has been proved as "good" in one of early SA articles - "work with module OFDM, FFT spectrum", we decided to return to a former format of CT display.

Good Luck ~

OFDM. COFDM: Rohde&Schwarz GN2130 digital voice modem

Rohde&Schwarz GN2130 digital voice modem

OFDM, Ch - 48, Sh - 56.25, Br - 44.4(4), QAM-16/PSK-4, k = 17/64

Author: SergUA6 

Band Width ~ 2700 Hz

Low Range ~ 360 Hz

Baud Rate 44.4(4) Hz

n-Ary (PSK/MPSK) Mixed QAM-16/PSK-4

Count of Carriers 48

Step between carriers 56.25 Hz

ACF Typical ~ 45 ms

RX mode  SSB

The record of GN2130 is here.

Sonorgams:

pic.1  General view

Diagrams:

pic.2 General quantity of the channels

pic.3 The constellation in the channel

R&S GN2130 - is the The voice modem, optionaly delivered to HF transceiver XK200 of R&S corporation. It is used for a speech transmission after conversions into a digital form, closing of the data by means of internal cryptoprocessor is possible. In this example, 48 channel OFDM signal is orginized, with standard enough parametres. 


Modulation in the channels is mixed QAM-16/PSK-4.  Features: it is necessary to mark presence of the auxiliary/pilot-symbols , in every second symbol through every one channel for synchronisation and customisation/fine tuning of the adaptive corrector the special signals are transmitted. Also there is a presence of the preamble with duration about 600 msec. Maximum common technical speed for QAM-16 is ~ 8533 bps.

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. 
*** 
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. 


*** 
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. 


*** 
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. 


*** 


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. 


*** 


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.