Hi Manuel,
On 03/05/2015 01:40 PM, Manuel David
Lozano Amezquita wrote:
Hi Marcus,
Now I have another question, How can I estimate the time shift
in fractional samples?, for example, I have a Cosine signal with
amplitude of 1 v, and 1 kHz, and I configure my sample rate in 1
MHz. Then I transmit that signal, and some time later I receive
it with another antenna, so How could I determine the time
difference of both?.
That is a question that seems to be central to your problem. I have
some approaches to answers, but explaining them in depth will take
rather long, and not explaining them won't actually help you. Have a
look at what a cross correlation is; you should be able to
understand what you need to do rather quickly.
The objective is to measure the distance between the Tx antenna
and the Rx antenna, And I know that distance=velocity/time, I
know the velocity but I need the time that the signal spends
from the Tx antenna to ]Rx antenna.
Yep, classical radio ranging problem; have a look at existing radar
algorithms. Also bear in mind that the temporal resolution of your
system is given by Nyquist's theorem, which leads you to in the complex case, to assess if
your application is feasible at all.
All the advices or tips that you could give me, I will
appreciatte it a lot.
In all honesty: what you're having are basic signal processing
questions, and you should read a textbook on signal theory. GNU
Radio has a suggested reading page, which might give you a start[1].
Greetings,
Marcus
[1]
https://gnuradio.org/redmine/projects/gnuradio/wiki/SuggestedReading
From: address@hidden
To: address@hidden; address@hidden
Subject: Re: [Discuss-gnuradio] How to show the internal clock
on the flowgraph
Hi Manuel,
your signal is sampled with a sample rate. You can now
estimate the time shift in (fractional) samples, and calculate
the "wall clock" time difference by dividing by the sampling
rate.
You, as a user, set the sampling rate that your device uses.
The B210 is very flexible in respect to that.
Best regards,
Marcus
On 03/02/2015 09:02 PM, Manuel
David Lozano Amezquita wrote:
Hi Marcus
Thank you for your time,
I need to transmit a signal and then receive
it, so I need the time difference between the two signals.
I thought that I need a clock in both so I could compare
in the same time scale the two signals. Thats why I need
the clock.
Or how can I take the time between the 2
signals?
Thank you!
El mar 2, 2015 2:53 PM,
=?ISO-8859-1?Q?Marcus_M=FCller?= <address@hidden>
escribió:
Hi Manuel,
On 03/02/2015 08:38 PM,
Manuel David Lozano Amezquita wrote:
Hi Marcus, I know that the clock of the
USRP b210 is 62MHz, but I need to show it on the
flowgraph to compare the phase of two signals.
I'm really confused. You *can* configure the master clock
rate, which is the rate at which the signal is sampled, to
be up to 61.44MHz, but that's neither the default nor
62MHz. There are several clocks in the B210, so maybe I'm
missing something.
Where does that freuquency come from? What does it
signify?
Why do you need it to compare phases? Of what?
Best regards,
Marcus Müller
Thanks
Manuel
El mar 2, 2015 2:26 PM,
=?ISO-8859-1?Q?Marcus_M=FCller?=
<address@hidden> escribió:
Hi Manuel,
could you explain what you mean with "internal clock
of the board"?
Best regards,
Marcus Müller
On 03/02/2015
08:04 PM, Manuel David Lozano Amezquita wrote:
Hi everyone,
I'm using a USRP B210 board, and I don't know how
to watch on the flowgraph the internal clock of
the board, I need it to compare the time
difference of two signals.
Please Help Meeeee.
Thanks
Manuel
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