Juha,
What type of demodulator did you have in the dongles used for the test?
--
Piotr
W dniu 25.05.2016 o 14:46, Juha Vierinen pisze:
> In my testing, this phase rate difference seemed constant and I could
> simply calibrate it out by looking at the phase rate term estimated
> from the phase of
Dear all,
Sorry, my source code was wrong.
There is only one
*d_bit_offset += d_nbits;*
*Thanks .*
2016-05-26 10:38 GMT+09:00 SangHyuk Kim :
> Hi all,
>
> I'm tracing how OFDM modulation is done by /ofdm/benchmark_tx.py.
>
> The file, ofdm.py indicates ofdm modulation is composed of like :
>
hello all
i am using the example of /gr-digital/examples/narrowbands
the benchmark_tx.py and the benchmark_rx.py ,and my devices are two B210
these is my command:
sudo ./benchmark_tx.py -f 175e6 -m bpsk --bitrate 500e3 --tx-gain 60
another computer
sudo ./benchmark_rx.py -f 175e6 -m bpsk --bitrate
Hi all,
I'm tracing how OFDM modulation is done by /ofdm/benchmark_tx.py.
The file, ofdm.py indicates ofdm modulation is composed of like :
modulation - mapper - preamble - IFFT - CP - scale
|- mapper - preamble -|
And I have a question at ofdm_mapper_bcv.
In ofdm_mapper_bcv_im
I'm trying to compile one of my custom OOT modules on this new Ubuntu 16.04
install and I wonder if I'm having compatibility issues. I'm getting what
looks like cmake issues that cause make to error out. I made sure to feed
the prefix location into cmake. There are warnings that I'm not used to
see
I just installed GR using Pybombs on a fresh Ubuntu 16.04 (16.04 not 14.04)
with no problems.
Rich
On Tue, May 24, 2016 at 5:30 PM, Ben Hilburn wrote:
> Hi all -
>
> Some great discussion here.
>
> We have talked about adding a "dry-run" option to PyBOMBS a couple of
> times in the past. It sou
The AirSpy uses the R820T2 chip for the tuner, but a different
sampling/DSP "engine".
Yes, making the charge-pump and "dither" mods will help with
phase-coherence.
Somebody needs to "own" the rtlsdr driver, and merge in the last couple
of years of field experience and branching that has gone on
Hi Marcus,
I don't know much about AirSpy.
Does it use the same demodulator chip as current RTL-SDR dongles?
And does it mean that change to low level part of rtlsdr driver might
help to get rid of that frequency offset?
--
Piotr
W dniu 25.05.2016 o 16:35, mle...@ripnet.com pisze:
>
> There are
Forgot to mention: of course I feel flattered by you mentioning me as
copyright holder, but I'd rather see you use the VOLK project as source.
I made that "being a part of the project" :)
Cheers,
marcus
On 25.05.2016 17:20, Marcus Müller wrote:
> Hi Raj,
>
> Ben is absolutely right. Feel free to
Hi Raj,
Ben is absolutely right. Feel free to use the logo in your presentations.
Rationale: I made that logo so that people could associate something
visible with VOLK. Now, having a logo that no-one uses is pretty much
stupid, hence, you should feel more than welcome to use it, especially
when
Hi Marcus!
Thank you for you reply!
So I am trying to make a OFDM system with and without codification (CC
code)... for this I am using these flowgraphs (simpleOFDM.png and
CodeOFDM.png)
The problem that I saw is: If I use just codification without modulation
(just to try), the output scope is
Hey all -
Planning for GRCon16 continues to go well, and we are looking forward to
another great conference year. Some quick notes:
The current deadline to submit an abstract for a talk is one week from
today, next Wednesday the 1st of June. If you haven't submitted your
abstract yet, please send
There are a couple of issues with the rtlsdr driver used by gr-osmocom
in this regard:
(A) The charge-pump loop current is too constrained for the higher
frequencies
(B) The "dither" option appears to have a bias that causes a (small)
frequency offset.
The driver that AirSpy uses fixes bo
Hi Sebastian -
Thanks so much for the great update! I have two questions:
You mentioned in your blog post that all adjacent bins will be interpreted
as one signal in your detection block, which then gets passed downstream to
the analysis portion of your design. Can you comment on how this might b
Hi Jose,
could you explain the problem a bit more in-depth? I'm afraid I'm not
really understanding.
By the way, if you sign up to the mailing list directly [1], you could
directly attach the "saved to image file" (file->screen capture in GRC)
output so that we can understand what you're doing.
Well, I resolved the second point... just put a Unpack K Bits after the File
Source block and then a Pack K Bits block before the File Sink block.
Someone could help me in the first question? The file that I received get a
lot of wrong information with just virtual transmittion... there is no noi
That, or simply, the output clock VCO changes its reaction to the
control voltage under certain circumstances (temperature, frequency) so
much that the control loop loses the ability to reach stationary
exactness (e.g. due to natural limits on the magnitude of the VCO
voltage). These devices defini
In my testing, this phase rate difference seemed constant and I could
simply calibrate it out by looking at the phase rate term estimated from
the phase of the cross-correlated noise. The samples stay aligned for
hours, so the issue is caused by the tuner or the DDC. One theory that I
had was that
Hi,
> of the drift remains a mistery (probably due to the implementation of the PLL,
> but I cannot understand why Phase Locked Loops would drift in Phase !).
If the phase comparator is digital ( i.e. a XOR ) and the input clock
is somewhat analog, the gate thresholds might vary depending on
temp
>From our own experience with dual-dongle measurements, the phase drift
seems to be strongly related to R820T(2) temperature. We reduced significantly
the phase drift by gluing a large heat sink common to both chips on both
dongles, without completely removing this effect (we aim at measurements la
Hi Juha,
It wouldn't be as simple as it was for me as a developer and as it
(hopefully) is for the end user without your hardware mod.
Can you say something more about the residual center frequency
difference? Where might it come from? I prepared little test of
coherency between the receivers (mu
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