On 25/06/2023 16:49, Arhum Ahmad wrote:
Respected sir,
I am using N-200 USRP for transmitting a signal. While transmitting, I
havechangedthe Gain value in the SDRutransmitting block, but my signal
strength at the receiver remains the same. I also stop and restart the
code but the change in gain does not affect the received signal. I
have tried the changing gain via both available options i.e., input
port and dialog, but it seems to have no effecton the receiver. The
signal strength at the receiver remains the same. I have tried 30
dB(Maximum gain) to 0 dB (minimum gain) in both cases received SNR is
the same(i.e.,15 dB). I am using a wireless connection in
line-of-sight, with minimum Tx gain at least a fewdropsin SNR should
be observed. I have also tried -50dB (just checking) but noeffect in
the SNR is observed. The same thing I havetried using B210 as Tx, Rx
signal strength does change in this case. However, while using N-200,
noeffect of changing the gain value is observed. Somehow gainvalue is
fixed in N-200 while using the MATLABSDRu block. Can you PLEASE HELP
ME!!! IT IS VERY, VERY IMPORTANT.
Well, neither usrp-users nor discuss-gnuradio are support lists for MATLAB.
You haven't mentioned which daughter-card you are using in the N200,
which would certainly help to fill in information about
what *might* be going on.
Does your receiver setup use AGC? Do you know what its set-points are?
If you simply look at the spectrum on the RX end as you vary gain on the
TX end, do you see a change? At the higher end,
SNR may not change very much, depending on how it is being measured,
etc.
