Hi,
I'm testing the basic packet transmission functions.
I use a vector source to generate binary stream, tag it, add crc, use a
protocol formatter to generate a header and mix the header with the
payload.
On the receiver end, I use a correlation estimator to do packet
detection, and use header/payload demux to seperate the header and the
payload. I use a message debug module and see that the header is parsed
successfully.
******* MESSAGE DEBUG PRINT ********
((payload symbols . 48))
************************************
However, the header/payload demux gives me error:
gr::log :CRIT: header_payload_demux0 - no payload length passed from header
data
As shown in the picture below, the correlation estimator does a good
job finding the starting of a packet.
[image: Screenshot from 2017-03-17 17-28-01.png]
Compared to the example in /gr-digital/examples/packet/, my design does not
include a polyphase clock sync. But I guess this is not the source of
problem because there is no noise induced.
I hope someone can have a look at my attatched grc file, and tell me what
is causing the problem. Any help would be much appreciated.
Regards,
Edwin
CPM_loopback_test.grc
Description: Binary data
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