[Discuss-gnuradio] Transients at burst rising edge

[Lakshay Narula]

Hello all,

I have been trying to perform ranging between nodes using time-of-arrival of signals. To this end, I am trying to transmit an accurately timed pulse using the USRP. My initial experiment simply sends out a 100 ms burst every 1 sec. I am then recording this signal using NI PXIe-5663 front end for analysis. Everything is working out fine, except that I am seeing some wild transients at the beginning of the burst for several nanoseconds.

I am attaching some plots that show this behavior at http://imgur.com/a/C0Ynq. The falling edges of the burst are very sharp. I would like to get something like that on the rising edge too.

In another post on the list (https://lists.gnu.org/archive/html/discuss-gnuradio/2012-06/msg00312.html), Josh said that "If you are seeing transients at the beginning of a burst, thats probably the half band filters. They are implemented in block ram and don't clear between bursts."

Is this the reason I am seeing these transients? Is there anything I could do to correct this?

Thanks,

Lakshay.