Well I finished writing the C++ DVB-S2 transmitter class today.
The final thing to do was to add the Gold code based symbol
scrambler. Next will be the difficult part, testing it!
It is interesting to note that S2 includes a 26 symbol preamble,
64 symbol modulation and code rate indication and the option of
sending pilot sequences in the transmission. This allows automatic
mode identification and enough information for a DFE (Decision
Feedback Equaliser) to be deployed in the receiver. Which makes it
suitable for channels with multipath.
The UHD driver for the Ettus USRPS has been upgraded, the main
improvement has been to further reduce the CPU load. I have not had
time to test it but a couple of releases ago the UHD load dropped
considerably, so much so that it became viable to transmit DVB-S using
my dual core Lenovo laptop.
I still have to get the 64 bit version of my DVB-T code to work. It will be
interesting to see whether I can get that to run on the laptop with the new
UHD.
No comments:
Post a Comment