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~