This last couple of months have been my first to get introduced to the
GNU radio. It has been a fun and frustrating learning experience so far.
I and my team member are using two USRP’s to communicate to each other.
We have been able to send and receive data by just sending a cosine wave
and or a bit stream successfully. But the problem is that when we try to
send a bit stream through BPSK we are not receiving the data correctly.
First of all we are using grc to run the blocks with a carrier frequency
of 2.5GHz with a bandwidth of 500KHz. On the receiver side we are using
AGC, a matchedou filter(rrc), pll, time recovery and a slicer to
finalize it. We are placing the FFT scope after the matched filter to
see if we are receiving any data and it seems like we are because you
can see the peaks changing as we change the frequency but our BER is of
1/2 therefore our system its not working.
We first thought we should make the online dbpsk source code working
prior to us attempting anything but not even running the modulation and
demodulation dbpsk block works.
Any suggestions or creative ideas are encouraged please.
We think it may be the parameters we are setting each block to be
although to our knowledge we have calculated them all based on our
carrier frequency and bandwidth. We also attempted placing a bandpass
filter after the antenna but it will not permit us, it gave an error.
The parameter used for that was of cutoff of high frequency of 2.501e9
and cutoff of low frequency of 2.499e9 with a transition bandpass of
500KHz or 1MHz.
I hope to hear from someone soon.