There are no libvolk optimizations for the LDPC encoder. I don't even
think it's possible. The encoder is just a giant XOR, but the XOR
operands are not from contiguous locations in memory.
Ron
On 3/18/21 05:42, Adrian Musceac wrote:
Hi Ron,
Tangential to the subject only, do you know if LDPC has optimizations
for ARM archs in libvolk? Arm64 mainly.
Thanks,
Adrian
On March 18, 2021 11:54:42 AM UTC, Ron Economos <[email protected]> wrote:
I haven't tried it, but it may be possible on a Raspberry Pi 4. I
wouldn't bother with anything less than a RPi4. I have successfully run
a modified DVB-T2 flow graph on a Beagleboard-X15, but only at 5 MHz
channel width (5.714285 Msps).
I've attached the flow graph. It uses short frames and 5/6 code rate to
limit the amount of LDPC processing. It also sends a lot of dummy
symbols, again to limit the amount of processing. However, it still
attains 19.057285 Mbps at 5 MHz channel width. If you can get it to run
at 8 MHz channel width, the bitrate will be 30.491656 Mbps.
It's also tuned for UHD v3.13.0.3-rc1. If you're using a later version
of UHD, change send_frame_size=65536 to send_frame_size=8192 in the UHD
Sink block. Using large USB frames helps to significantly lower
processor load, but this feature has been removed from later versions of
UHD.
Ron
On 3/18/21 04:17, Ali G. Dezfuli wrote:
Hi all, Is there any experience in transmitting DVB-T2 with
gnuradio and raspberry pi (any version)? I just wonder if it
can work real-time with about 9 MHz sampling frequency of 8
MHz DVB-T2. Thank you! BR, AGD
