Hi!
I have installed GRC3.8 and was working on BPSK based packet
communication using LimeSDR. It doesn't seem o improve things much. All
the packets that I receive are rejected due to errors in reception and
header parser fails. I think it's the correlation estimation block of
the AGC in the system which is creating this issue.How should I ensure
that the calibration of correlation estimator and AGC is correct and its
not introducing errors at receiver? Could someone point me to the
sources that can help.
Thanks
SG
On 19/05/20 3:37 pm, Shruti Gupta wrote:
Hi!
Thanks for your reply.
While I'll work on installing and working with GRC 3.8, I was just
wondering will the over the air communication be bad enough to not
even receive a single correct packet? Is it to do with loop_bw for
FLL, PFB and Costas_Loop or the digital gain values (a multiply block
for the source signal) in RX? What is the logic behind setting of the
loop_bw of these blocks?
Thanks and Regards
SG
On 15/05/20 6:34 pm, Shruti Gupta wrote:
Hi!
I have been trying to use the packet communication examples under
gr-digital in GNURadio(v 3.7.14.0) on ubuntu machines with LimeSDR
Mini for over the air communication. I am using the
usrp_packet_tx.grc and uspr_packet_rx.grc to transmit and receive
BPSK modulated packets respectively. I have modified these examples
for LimeSDR Mini by including LimeSDR source and sink blocks and
setting up the parameters. Now, I am running TX on one machine and RX
on another machine tuned to same frequency. However, when I keep the
gain values for RX low since the distance between TX and RX is few
feet and eliminating the possibility of RX saturation, the packets
are not being detected, while for higher gain values packets get
detected but the correlation start tags are tagged before the
position of estimation tags. I am not too sure if that's how it is
suppose to work.
Moreover, even after being detected the packets are not decoded and I
receive following message on console:
INFO: Parser returned #f
I think this is due to either incorrect header decoding or incorrect
packet detection which freezes the header/payload demux block in the
flowgraph. Also, even for very few packets that are decoded, the
header is incorrect so why does the packet even gets decoded? Is
there a way to work around this problem? Can we use some other block
for packet detection?
Any suggestion or help is highly appreciated.
Thanks in anticipation
SG
