There are Video Picture (TV Pictures) send by using OSN1500 and encoder/decoder equipments (Huawei Equipments) as the following:
Original TV Picture -- DS3_Out port of Encoder (DXT8800) � PL3_IN port of OSN1500 -- out Loop in PL3 -- PL3_OUT port of OSN1500 -- DS3_IN port of Decoder (DXT8300) -- TV Monitor (1741A Waveform/Vector Monitor)
At the receiving point by make loop from the OSN1500, there were small losses & distortions resulted on the waveform of the pictures on the TV Monitor “1741A Waveform/Vector Monitor” (Show Fig2 & Fig3) but the picture on the TV Picture Monitor is ok (Show Fig1).
In the video picture transmission standard, the picture should pass through more processes such as: DCT (Discrete Cosine Transform), Quantization, Zig-Zag Process, Encoding …
So the DCT Transform uses to convert the time domain to frequency domain, and then separate the frequencies to high frequency and low frequency. The quantization process use to delete the information that has low information and non-important information that no need to send “high frequency”.
So the result picture at the receive point should be ok, but if we check the waveform for this picture the result will be small loss in the result and this loss is normal because the loss that occurred from the above processes and it should small. But if we need to check the waveform we should first know the quality parameter of the picture.
1. We checked the ground for the OSN1500 and Encoder/Decoder, and we got it ok.
2. We checked the feedback picture on the TV Monitor and it was ok.
3. We make direct loop from the original TV Picture to TV Monitor (1741A Waveform/Vector Monitor) and the result was ok.
4. We changed the equipments to other room to check if there are radiations in that room, and the result also same
5. We checked the cables and the cable connections and interface and then we changed other cables, and no any result.