When I ran the example ofdm_loopback.grc,
i used a file source to send data through the transmitter and checked
the
output after the receiver in a file sink ;
i found that if the packet required to be sent is less than the defined
packet_length ; then the packet is not sent ?
how to send the last packet in this case ?
Hi GP,
ofdm_loopback.grc covers only the physical aspects of the transmission.
What you are describing is a flow control problem; you’d need to figure
out yourself how to make your data stream fit into the packets. A
typical way would be to send the length of your file, and then just fill
up the last packet with random data/redundancy/zeros; however, what will
happen if you lose one packet?
In a real-world application, you’ll have some content header, you’d have
channel coding/FEC, possibly some ARQ scheme, in case of multiple users
a MAC etc; whereas you “only” stream bits out of a file. Complete,
versatile transmission systems is what people build atop of transmission
systems such as the GNU Radio-supplied OFDM packet transmitters (which
primarily serve as good examples and showcases for the mechanisms
involved).
Hope that was a little helpful,
Greetings,
Marcus