z as shown in the
flowgraph attached, but I wasn't clear on the next step to filter. I am
sure you will have more thoughts on the flowgraph.
I have the sample file with the captured IQ samples, if you would like to
have a look:
http://sites.noise.gatech.edu/~abhinav/tmp/plc_message_500kHz.dat
PS?
>
> cheers
>
> Chris
>
> On Tue, Jun 7, 2016 at 6:35 AM, abhinav narain
> wrote:
>
>> Hi all,
>> I am trying to make a covert communication channel using SMPS noise
>> generated by the processor as a part of my research.
>>
>> I see a chang
Hi all,
I am trying to make a covert communication channel using SMPS noise
generated by the processor as a part of my research.
I see a change in frequency emitted by the processor when I run the
following loop (http://pastebin.com/uRghLuLm) with message variable
containing the message, and see t
Hi Marcus,
>
>>
> Not at all!
> Sorry, I was taking pictures of hardware and hence just took one for
> the GRC too. As I showed in previous picture, I am only using RX-B. I
> am not sure how to connections will be for dual mode, but currently I
> am just using one. I get complex values in the GRC
Thank you for your time,
Abhinav
Best regards,
> Marcus
>
>
>
> On 27.04.2016 19:13, abhinav narain wrote:
>
> Hi all,
> I want to sample first 250KHz on the channel.
> I am using the (sampling_with_lowpass.JPG) setup to extract quadrature
> samples.
> I ha
Hi all,
I want to sample first 250KHz on the channel.
I am using the (sampling_with_lowpass.JPG) setup to extract quadrature
samples.
I have LFRX card where i just use the RX-B pin to extract complex samples
from the channel.
My question is (question.JPG) how are the two setups different, assumin
Hi Marcus,
>
> It applies, but you must be aware of the fact that transmissions have a
> different ratio of "on" symbols and "off" symbols have different
> energy/power. So without knowing how many ons and offs you were sending,
> that number is pretty meaningless.
>
Thanks for pointing out this
Hi Marcus,
>
>>
> I am simply doing OOK.
>
>
>> Generally, [image: $\frac{S+N}{N}$] is only really a useful measure if
>> you either have
>>
>>1. a constant power modulation (e.g. PSK), or
>>2. whiten your over-the-air bits sufficiently (using *coding*), so
>>that for (stochastically s
>> that *exactly and reliably* correspond to the symbol timing; that's why you
>> need timing recovery. The question here is: what do you actually need? The
>> IQ samples before timing recovery aren't useful to the decoder.
>>
>> Just to assure you: AGC2 doesn&#x
ultiplies with a factor that changes so that average power stays the same.
>
> Best regards,
> Marcus
>
>
> On 01/25/2016 06:26 PM, abhinav narain wrote:
>
> Hi All,
>
> My problem is that above calculation sort of works, and isn't it exact.
> I have the follo
03 AM, abhinav narain
wrote:
> Hi all,
> This might be too simple, but I wanted to confirm as I am not sure how the
> blocks manipulate the IQ samples and how AGC works, does it add more
> samples for compensating the noise average or not.
>
> I have a flowgraph(image attac
to think that was a message.
I think I might want to do external synchronization to demonstrate this
idea, but I am unsure how to kickstart and test it using N210 USRP
hardware. Any suggestions will be greatly appreciated!
Thanks,
Abhinav
> Best regards,
> Marcus
>
>
>
>
&g
receiver, I get more number of non-bold zeroes than what I
expect(=8).
Is this something that I cannot solve because of
clock-drift/synchronization, or is my flow graph incorrect causing this ?
Thanks,
Abhinav
On Tue, Nov 10, 2015 at 12:58 PM, abhinav narain
wrote:
>
>
> On Tue, Nov 10, 2
On Tue, Nov 10, 2015 at 12:45 PM, Marcus Müller
wrote:
> Hi Abhinav,
>
> sorry, I might just be tired right now, but I don't understand this
> sentence:
>
> On 10.11.2015 21:18, abhinav narain wrote:
> > I have now fallen to doing PPM where I map {0,1} bits t
his is a problem as I cannot decode my symbols.
Is this a problem with clock drift and cannot be fixed with gnuradio ?
Do you recommend any other way to deal with it ?
Thanks,
Abhinav
> Best regards,
> Marcus
>
>
> On 10/12/2015 06:00 PM, abhinav narain wrote:
>
> Hi,
>
rm is
changed. Please see the grc attached, I would be grateful to you if I could
get clarity on it.
Thanks,
Abhinav
> Best regards,
> Marcus
>
>
> On 21.10.2015 22:45, abhinav narain wrote:
>
> Hi Marcus,
> I see your point, and I can add intepolation factor as 196K/2K =98 in
red in my reply to your
> reply to Sylvain's mail; basically, yes, you need to use a sampling rate
> >=196kHz, but no one is stopping you from putting any signal into that
> sampling rate that has a smaller bandwidth. See my comments on oversampling.
>
> Best regards,
> Marcus
>
Hi Sylvain,
> > You can see the spectrogram at the receiver. I want to do narrowband(1
> kHz)
> > transmission hence I am keeping the sampling freq at transmitter at 1k.
>
> That sentence is just wrong. It's actually quite the opposite.
>
> By keeping the sample rate at the transmitter at 1k, you
ed Sylvain's advice. Just oversample your signal by using an
> interpolating FIR filter to something that the USRP can happily work with.
>
> So, here is what I am not clear about- I should use 196 KHz as sampling
rate ?
So, the minimum BW of my signal will 196/2 =98KHz, and that is the b
only two blocks on receive side, instead of using the
FLL-BandEdge block.
Thanks,
Abhinav
On Mon, Oct 12, 2015 at 2:21 PM, abhinav narain
wrote:
> Hi Marcus,
> I messed that up! I am not sure if formatting is correct in the copied
> message, but yes I have emailed it to the discuss list n
This is the grc file if someone would like to run it on their setup.
On Mon, Oct 12, 2015 at 9:00 AM, abhinav narain
wrote:
> Hi,
> I am trying to transmit -1,0,1 { [1]+ 100*[0]+[-1] }, basically BPSK lot
> of 0s filled in between at certain frequency. I have few questions.
> &q
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