This is my first post in the community. I have been thinking about doing
this question, but after having reviewed some of the theory with digital
signal processing, usrp architecture and some approaches for
positioning/raning, I think I need to ask to the expert community,
find a line of work and to know the restrictions for the application we
to carry out.
I would like to measure the distance between two radios at short
(we have two UN-210 and two XCVR2450 or 1 WBX and 1 DBSRX2, let’s say to
m, 2m…up to for example 20 meters), starting from off-line
and finishing with real time measures in line of sight. My questions
- What would be, from your experience, the best approach to do this
(transmitted signal and digital processing in the receiver part), what
accuracy should I expect in line of sight?
I am looking mainly for a starting point, the signal structure to
and the receiver structure. For example, one of the thoughts I have is a
correlation in the receiver of a pseudorandom (spread spectrum)
signal, this approach could serve to measure time of arrival by
the delay of the pseudo-noise code signal, when comparing it with an
copy at the receiver. Another approach I have seen is the estimation of
Channel impulse response (CIR), that maybe (as far as i know) could
also for estimating distances. I have seen that there is some code to do
correlation inside the FPGA of the USRP1.
So far my references are (which maybe can be helpul for those who are
working in the same field):
“Advancing Wireless Link Signatures for Location Distinction”. Here,
do not carry out ranging/positioning, but a change in the transmitter
position is detected. In my case (in the case ranging is not possible),
detect if a distance is crossed would be my objective (e.g. the
go closer than 1 meter to the receiver).
“RF Ranging for Location Awareness”. In this dissertation they use an
arquitecture similar to the USRP hardware.
As you can see what I am looking for is for some sort of radar/ranging
application and some starting point. Also, my questions are very generic
now and I apologize for it, mainly because I am still looking how to
Then, any help (references, similar work done) will be very useful.