Hello,
I am a new GNU Radio user. I am looking to build a system that can transmit a packet at a pre-defined time with very high accuracy (about 1 nanosecond). Having gone through the mailing list I am aware that timed transmission is a common task and many people have asked similar questions. However, I am still a bit confused.
1. I see that there is an example tx_timed_samples that comes with the UHD source code. This is in C++ and uses the UHD API. Am I right in thinking that when implemented this way, it has nothing to do with GNU Radio at all? Is there any "reported accuracy" of this method in terms of difference between actual and required time of transmission?
2. I also see that it is possible to achieve similar objectives using tx_time stream tags in GNU Radio. My question is if this method is equivalent to method 1 in terms of what goes on "under the hood"? If not, how do these differ, and which method would provide better accuracy in terms of agreement between actual and required time of transmission. Does GNU Radio use the UHD API "under the hood"?
Please feel free to point me to resources I can read to get a better understanding of this architecture and relationship between UHD, GNU Radio, and USRP.
Thanks,
Lakshay.