Hello all,
I'm working on an SDR project where I need to transmit a narrow
baseband signal on multiple different carriers simultaneously, over a
relatively wide bandwidth (1Mhz). Essentially, when working normally,
the system acts as a radio passthrough, retransmitting the existing
channels, but
On 10/28/2019 12:55 PM, Daniel Estévez wrote:
El 28/10/19 a las 1:02, Marcus D. Leech escribió:
Here's the latest version of our 21cm sky map, derived from nearly 5
months worth of data from our 21cm spectrometer instrument.
All of the real-time processing is handled, naturally, with Gnu
Hi Markus,
yeah, that sounds right, but:
You'd probably want to use a PLL frequency detector (similarly
parameterized) to detect these and output a frequency estimate, and
then do some math on that estimate, and use it to correct the system.
Best regards,
Marcus
On Mon, 2019-10-28 at 16:41
Hi Barry and Bill,
> I don't know how wide a spectrum the PLL can handle.
Generally, that's not really inherently limited by anything but the
loop bandwidth.
It's a really simple PLL, with a complex sample-argument phase
detector.
In other words: if you set the loop bandwidth too high, the PLL
Hi Ivan,
that sounds a classical case of impossible to do in graphical, trivial
to do in Python.
So, write your hier block in Python – you could also base it on your
GRC-generated python file (and save it somewhere else, so that it
doesn't get overwritten).
Best regards,
Marcus
On Mon,
To all who gave me good ideas and insights,
Thank you for your help. Based on all of your comments, I have a new and
improved AM receiver which automatically corrects small tuning errors.
Attached is a picture of the flowgraph.
Best regards,
---
Barry Duggan KV4FV
On 2019-10-28 12:21,
Hi all!
I’m implementing my own testbed in GRC using hierarchical blocks to obtain a
clearer flowgraph.
I need to have a dynamic amount of instances of a particular sub-block, that I
can set as parameter of the higher level block.
How can I solve my problem? It could be very cool!
Thank you.
I’m working on the technical memo at the moment.
Sent from my iPhone
> On Oct 28, 2019, at 2:26 PM, Daniel Estévez wrote:
>
> El 28/10/19 a las 1:02, Marcus D. Leech escribió:
>> Here's the latest version of our 21cm sky map, derived from nearly 5
>> months worth of data from our 21cm
El 28/10/19 a las 1:02, Marcus D. Leech escribió:
> Here's the latest version of our 21cm sky map, derived from nearly 5
> months worth of data from our 21cm spectrometer instrument.
>
> All of the real-time processing is handled, naturally, with Gnu Radio,
> and then some Python post-processing.
The final aim is to build a transmitter and receiver for 802.11p DSRC
packets.
The receiver is currently using 802.11a, for testing purposes, but I do
have a flowchart they successfully receives 802.11p instead.
I've figured out what I need to put in the file source (message binary, not
.pcap),
Hi Markus,
From what I can tell, the PLL Carrier Tracking block does the
correction, but it doesn't tell you what it did, so I'm not sure you can
log the offsets. There are other PLL blocks I haven't looked at yet, so
I don't know about them. See
The PLL Freq Det is the one I would like to figure out.
Bill Dailey
Negativity always wins the short game. But positivity wins the long game. -
Gary Vaynerchuk
Don’t be easy to understand,
Be impossible to misunderstand
- Steve Sims
> On Oct 28, 2019, at 11:01 AM, Barry Duggan wrote:
>
>
Dear OMs,
I guess this carrier tracking block would be useful to handle frequency
drift of cheap (unstabilized) devices, when working QO-100 satellite
connections. This block could be used to find the band end beacons and
derive the frequency shift and correct it accordingly. Right?
vy73
markus
Hi Bill,
Look at https://wiki.gnuradio.org/index.php/PLL_Carrier_Tracking. I
think I will add this formula to the Notes: radians per sample = 2 * pi
* freq / sample rate
I don't know how wide a spectrum the PLL can handle.
I am working on the documentation of blocks, so let me know if there
Hi Adam - Check out this presentation from GRCon19 <
https://www.gnuradio.org/grcon/grcon19/presentations/managing_latency/ >.
The basic issue is that the FIFO buffer between the source and next block
will fill up with data, so any change to the source value will be at the
end of the FIFO &
Can you give a little primer on using that PLL tracking?I would love to use
that to just track carriers random frequencies. For instance 10mhz.
Ultimately I want to track and periodically log and offset from true predicted
frequency. Like every 10 seconds.
Bill Dailey
Negativity always
Hi Albin and Volker,
I added a PLL Carrier Tracking block to take care of the tuning problem.
See the revised https://wiki.gnuradio.org/index.php/File:FunCube_AM.png
Albin, that 'spike' is the carrier! This is AM ;)
Thank you both for your suggestions.
---
Barry Duggan KV4FV
On 2019-10-27
Hi List,
I'm trying to understand the latency behavior of the Stream Mux block when two
streams of unequal lengths are being multiplexed together. Attached is a
minimal flow graph that illustrates the point.
In the example, two streams are multiplexed: one Vector Source of length 50 and
one
" but my wi-fi packet receiver works just dandy without any OFDM blocks"
--> Can you check the standard which your wifi receiver is following ? If
it is 802.11b, then it wont work with gr-ieee 80211 because gr-ieee 80211
is based on OFDM based WiFi.
You cannot use .pcap file as file source for
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