Hi, All
I have very trouble
My experiment enviroment isUBUNTU 11.04 , USRP N200, DBSRX2 ,active
antenna and gnuradio
I am worrying about good software GPS receiver is not$B!!(Bexist .
I want to receive L1 signal , and want to demodulate that signal
However GPS signal is used Spread spectrum modulation scheme.
I try to creating gnuradio-companion’s blocks.(use to Spread spectrum
demodulation blocks)
but that is very difficult so Now I think method is
I am sure, with the source, you could adapt it to use the USRP
recorded signal, and then possibly port the MATLAB over to either
Python (using Josh’s signal processing in Python blocks) or straight
C++.
I am sorry that My English is not good
Kouki
Good luck - it’s definitely not a trivial task, but it sounds extremely
fun.
My group is using USRPs to do the task Kouki described, although our
flow
diagram is a little different. We only use the USRP2 to receive the raw
RF
data which is written to file. This data is processed to the point
where
we decode the navigation bits, but no position is ever found. We’re
more
interested in the effects of ionosphere scintillations on GNSS signal
structure so we don’t need to calculate antenna position.
I can recommend two books that have helped me immensely. The Kaplan
“blue
book:”
I do know of a group that has used a USRP1 to develop a 4 channel L1
receiver, but they had to modify the FPGA to do all the real time
processing. Let me know if you have additional questions!
What did you use for your setup, ie daughterboards, antenna and LNA (if you
do not mind my asking). I have been trying a setup for months that uses a
DBSRX2 and a mighty mouse 2 antenna only, but I have never been able to
acquire the L1 signal. I am wondering where I have gone wrong in the setup.
I’ve successfully used a DBSRX + active antenna to receive GPS signals
before. What software are you using to do the correlation and find the
L1 signal?
What did you use for your setup, ie daughterboards, antenna and LNA (if
you
do not mind my asking). I have been trying a setup for months that uses
a
DBSRX2 and a mighty mouse 2 antenna only, but I have never been able to
acquire the L1 signal. I am wondering where I have gone wrong in the
setup.