It seems my old patch that zeroed out the output of the USRP didn’t make
it into UHD- we’re seeing a constant sine output between packets- and in
our case this messes with the receiver unless we use some custom TX
cards that have an amp we can shut down with ATR.
I’ve never noticed this with my work with the UHD. There are various
commands issued to the USRPs to turn it on and shut it off between bursts.
Maybe there’s something missing in the gr-uhd.
On the other hand, Josh and Nick have been working on using tags with gr-uhd
on the transmit side, which should fix your problem.
Any comments from the UHD folks?
The usrp1 shutdown mechanism in UHD is a little soft (because there is
no inline metadata with the samples). However, if you mark end of burst,
then the transmitter should get disabled.
It looks like the patch involves verilog changes. Is this an image that
you can just build and drop in place of the existing one or does it need
host code support? Have you tried it?
I’ve never noticed this with my work with the UHD. There are various
commands issued to the USRPs to turn it on and shut it off between bursts.
Maybe there’s something missing in the gr-uhd.
On the other hand, Josh and Nick have been working on using tags with gr-uhd
on the transmit side, which should fix your problem.
Any comments from the UHD folks?
Brett, if you are using anything beside the BasicTX or LFTX, then it’s
also possible you are seeing LO feedthrough/DC offset in the transit
mixer, which results in a carrier output between packets.
On Sun, Sep 25, 2011 at 8:07 AM, Brett L. Trotter [email protected]wrote:
It seems my old patch that zeroed out the output of the USRP didn’t make
it into UHD- we’re seeing a constant sine output between packets- and in
our case this messes with the receiver unless we use some custom TX
cards that have an amp we can shut down with ATR.
Is there any way to fix this?
I’ve never noticed this with my work with the UHD. There are various
commands issued to the USRPs to turn it on and shut it off between
bursts.
Maybe there’s something missing in the gr-uhd.
On the other hand, Josh and Nick have been working on using tags with
gr-uhd
on the transmit side, which should fix your problem.
Any comments from the UHD folks?
Tom
This forum is not affiliated to the Ruby language, Ruby on Rails framework, nor any Ruby applications discussed here.