Setup #1: from Germany
Thomas Pinz (FH-Regensburg) kindly provided some screenshots taken from the real hardware. He used the Vector Signal Generator ESG4483 from Agilent to produce an IF signal, starting from the time samples obtained by dvbtenco output (after some sort of format adjustments). The input signal was 1'000'000 byte long, generated by mpeg2gen, and the time waveform had 22 Million Samples. He used the FSP spectrum Analyser of Rohde&Schwarz to observe the signal in the frequency domain. In order to have a term of comparison, he also used a DVB-T SFQ signal generator from Rohde&Schwarz. The SFQ has 3 dB more output power to detach from dvbtenco. The parameters are: 8k, QPSK, guard 1/4, code 2/3. In the following figures, you can see what he has found! (big dimension, but small size)
- 36 MHz IF whole spectrum, average + FFT filter (green dvbtenco, blue SFQ)
- 36 MHz IF signals shoulder spectrum, average + FFT filter 1 kHz/div (green dvbtenco, blue SFQ)
- 36 MHz IF signals shoulder spectrum, average + FFT filter 50 kHz/div (green dvbtenco, blue SFQ)
- Measured amplitude probability distribution generated by dvbtenco
- Measured amplitude probability distribution generated by SFQ
- Measured complementary cumulative distribution function generated by dvbtenco
- Measured complementary cumulative distribution function generated by SFQ
Setup #2: from Taiwan
Hung-Jen Chang of Agilent Taiwan has kindly provided a snapshot of a test setup, where they used dvbtenco and succeded to succesfully receive a signal on a commercial set top box. This is a description of what you can see in the photo (click on the image to get a more detailed view).
- Left, bottom: Agilent E4438C vector signal generator with opt. 602 with 64MB memory and digital interface with N5101A, emitting the RF signal by the small dipole antenna
- Left, middle: Extension box containing the Agilent N5101A fading simulator card (black box)
- Left, top: Notepad with N5101A Baseband Studio control software
- Center, bottom: Agilent ESA E4405B spectrum analyzer with special opt. for DVB-T signal analysis
- Center, top: Notepad with Agilent E9285A analysis software
- Right, bottom: TV set showing the video&audio contents of the MPEG-2 TS
- Right, top: Panasonic commercial DVB-T set top box, receiving the RF signal
Setup #3: in Office
Thanks to the courtesy of Paolo Monzoni of Agilent Italy, I had the chance to test the operation of the software encoder. I did this using an ESG 4438C Vector Signal Generator from Agilent. Basically, I managed to display a static frame from a transport stream, using the ESG as transmitter and an USB DVB-T receiver locked to my laptop.
This is the main screen of the 4438 SG. You can see the carrier frequency and the sample clock used.
This is the HW setup: top, the ESG 4438C signal generator, down, the Cynergy T2 USB DVB-T receiver (the blue led on means that there is a lock). The CDROM is there used only as a base for the RX antenna!
The screen of the Terratec software, showing the results of a scan: you see the "R&S Factory" program
The receiver gets the lock, and the Terratec software displays the main transmission parameters.