Did you account for the 0-180 phase ambiguity when demodulating BPSK?
This would produce an inverted bitstream which wouldn't be noticeable
when transmitting alternating 1s & 0s.
@(^.^)@ Ed
On 8/10/20 2:50 AM, Shruti Gupta wrote:
Hi all!
I am working on implementing BPSK communication system with SDR in
GNURadio. I tried implementing packet-communication in GNURadio using
two systems each acting as TX and RX. Using the examples provided in
gr-digital , I tried running TX and RX with LimeSDR Mini, but was unable
to get them to work. In order to identify and solve the issues, I moved
on to implementing everything in step-wise approach, as in-
1. Transmit just alternating 1’s and 0’s using BPSK modulation and
receiving it on other end using synchronization and demodulation.
2. Introduce packet structure into the previous raw-communication model .
3. Then add FEC into the system and finally include CRC and achieve the
same packet-communication as provided with gr-digital.
In this step-wise approach, I was able to get raw communication model
(point 1 in above) work properly. However, I am not able to get packet
version (number 2) working. I used the same system settings just the
introduction of packet structure at TX and correlation estimation &
header-payload demux at RX but still no luck. Is there some issue with
the way I am implementing packet formation at TX or the correlation
estimator is the problem? You can find my implementation at following link:
https://drive.google.com/drive/folders/1TIWhNuVmclenhLj4qJK2HT-er6RoCcco?usp=sharing
Any suggestions/pointers in order to resolve the issue will be helpful.
Thanks and Regards
SG
