On Wed, Apr 7, 2010 at 1:18 AM, Makmur Hidayat wrote:
> Dear all,
>
> I try to make simulation for qam loopback. But there is an error:
> RuntimeError: hierarchical block 'qam8_demod' input 0 is not connected
> internally
>
> What is the error mean?
>
> Thank you for your help
> Makmur
The QAM re
Dear all,
I try to make simulation for qam loopback. But there is an error:
RuntimeError: hierarchical block 'qam8_demod' input 0 is not connected
internally
What is the error mean?
Thank you for your help
Makmur
File "/home/makmur/sim_qam_loopback.py", line 150, in
tb.Run(True)
File
"/u
Hi All
I am trying to understand how the optimised modified Mueller and Muller
algorithm is implemented in GNU Radio.
I had a look at the method gr_mpsk_reciever_cc::mm_error_tracking, to
see how this is done. As far as I can tell, lines 242-245 are intended
to implement equation (8) of the refer
On 04/06/2010 09:44 PM, John Gilmore wrote:
>> Which part of the Linux issue... sustained throughput or latency? I
>> wouldn't be surprised to find that latency hasn't
>> improved substantially because it's not a priority for server software.
>> Even VoIP applications are not concerned
>> about
> Which part of the Linux issue... sustained throughput or latency? I wouldn't
> be surprised to find that latency hasn't
> improved substantially because it's not a priority for server software. Even
> VoIP applications are not concerned
> about a 1 msec improvement... whereas that makes or br
Hi all,
I have several basic questions on about build a MIMO system with two
USRP2s. I have my master board connect with the computer and the
external clock. The slave board is connected to the master by the MIMO
cable. I am working C++ and I have the SISO working now. My questions
are as follows
Hi Veljko,
> What I got from your paper is that the matched filter approach for
> fast packet detection would not work in an OFDM setting. What about
> fast ACK generation? Would it require an IFFT implementation on the
> USRP? Would it help much?
>
It's a good question, and something I haven't
PS. if you haven't seen, SORA is able to interoperate with 802.11g, which
is impressive. It meets all of the timing requirements. However, it does
not come with the exact ease of programming that we're familiar with. They
do have to push the use of SSE and tradeoff a lot of computation for memo
>
> Did you see my previous post about the accelerator PCIe card? To some
> extent the Microsoft approach is what we're
> doing. But we want to stay compatible with USRP2 hardware so we connect
> GbE to the accelerator card; non MAC-related
> dataflow is PCIe from there. Buffering required to st
On Tue, Apr 6, 2010 at 5:35 PM, Jeff Brower wrote:
> Philip-
>
> > On 04/06/2010 04:19 PM, George Nychis wrote:
> >> Jeff, I definitely agree that buffering also adds significant latency.
> How
> >> much of the MAC can you get around? I just think that, there are a
> number
> >> of people who w
Charles-
>> I would tend to blame Linux and buffering more than GbE itself (MAC + PHY).
>> Here is an interesting doc where the
>> researchers were asking similar questions:
>>
>> http://www.hep.man.ac.uk/u/rich/atlas/docs/atlas_net_note_draft5.pdf
>>
>> I'm not sure yet how much buffering is d
Philip-
> On 04/06/2010 04:19 PM, George Nychis wrote:
>> Jeff, I definitely agree that buffering also adds significant latency. How
>> much of the MAC can you get around? I just think that, there are a number
>> of people who want the flexibility of the SDR, but want to do MAC research,
>> and
George-
> Jeff, I definitely agree that buffering also adds significant latency. How
> much of the MAC can you get around? I just think that, there are a number
> of people who want the flexibility of the SDR, but want to do MAC research,
> and current common SDR architecture is just not good en
Hi George,
2010/4/6 George Nychis :
> Jeff, I definitely agree that buffering also adds significant latency. How
> much of the MAC can you get around? I just think that, there are a number
> of people who want the flexibility of the SDR, but want to do MAC research,
> and current common SDR arch
On 04/06/2010 04:19 PM, George Nychis wrote:
Jeff, I definitely agree that buffering also adds significant latency. How
much of the MAC can you get around? I just think that, there are a number
of people who want the flexibility of the SDR, but want to do MAC research,
and current common SDR ar
On 03/30/2010 11:48 AM, Jeff Brower wrote:
Matt-
We're working on a project at Signalogic to interface one of our DSP
array PCIe cards to the USRP2. This would provide a way for one or
more TI DSPs to "insert" into the data flow and run C/C++ code for
low-latency and/or other high performance a
Jeff, I definitely agree that buffering also adds significant latency. How
much of the MAC can you get around? I just think that, there are a number
of people who want the flexibility of the SDR, but want to do MAC research,
and current common SDR architecture is just not good enough. We need lo
> I would tend to blame Linux and buffering more than GbE itself (MAC + PHY).
> Here is an interesting doc where the
> researchers were asking similar questions:
>
> http://www.hep.man.ac.uk/u/rich/atlas/docs/atlas_net_note_draft5.pdf
>
> I'm not sure yet how much buffering is done in the USRP2
Two independent PC+USRP nodes. All the ACK related logic was
implemented at the Python layer.
Another thing that I tried was to connect the two nodes via Ethernet
(I have two Ethernet NICs in each of the PCs) and then use USRPs for
data and Ethernet for ACKs. I still couldn't get good results,
alt
I'm trying to make DBPSK modulation with costas alfa set to 0.05 and gain mu
set to 0.001. I got all of trues but I could not understand where can I see the
received packages ( 1 or 0 ). And in benchmark_tx code there is an option "
--from-file " to specify the file but i could not decide h
Veljko-
> I tried with a stop-and-wait ARQ and two USRP2s with XCVR2450s, but
> the delay was too long and inconsistent. I can't remember the exact
> figures, but definitely up to milliseconds.
Do you mean two USRP2s back-to-back? Or both connected to motherboard ports?
-Jeff
> 2010/4/6 George
Thank you so much Johnathan. Is that means the signal is converted before ADC?
I'm quite confused about how the FPGA configuration connect with host code. The
FPGA bitstream is loaded by usrp.source_c or usrp.source_s. Where is the FPGA
bitstream loaded into? How does the usrp source class load
I tried with a stop-and-wait ARQ and two USRP2s with XCVR2450s, but
the delay was too long and inconsistent. I can't remember the exact
figures, but definitely up to milliseconds.
Veljko
2010/4/6 George Nychis :
>
>
> On Tue, Apr 6, 2010 at 10:07 AM, Charles Irick wrote:
>>
>> Thanks for the rep
George-
>> Thanks for the reply George. I'm still looking for a little more
>> information on this topic.
>>
>> - What is PMT
>
> http://gnuradio.org/redmine/wiki/1/TypePMT
>
>> - Why was m-block removed
>
> http://osdir.com/ml/discuss-gnuradio-gnu/2010-01/msg00066.html
>
>> - Has anyone measured
On Tue, Apr 6, 2010 at 08:19, Yan Nie wrote:
> I'm trying to understand how Digital Down Conversion Implemented in
> gr-sounder project. The DDC needs to be implemented in FPGA, but there isn't
> any module in FPGA configuration implementing DDC. How does the receiver in
> gr-sounder implement Di
Dear all,
I'm trying to understand how Digital Down Conversion Implemented in gr-sounder
project. The DDC needs to be implemented in FPGA, but there isn't any module in
FPGA configuration implementing DDC. How does the receiver in gr-sounder
implement Digital Down Conversion?
Thanks a lot in
i am using the RFX-2400 with usrp-1
*i would like to know what is the minimum amount of data/ minimum number of
packets that the usrp can receive*.
i used the benchmark_rx file and changed the default packet size to 10
bytes. by using the --from-file option and sending only 1 packet (10 bytes)
of
On Tue, Apr 6, 2010 at 10:07 AM, Charles Irick wrote:
> Thanks for the reply George. I'm still looking for a little more
> information on this topic.
>
> - What is PMT
>
http://gnuradio.org/redmine/wiki/1/TypePMT
> - Why was m-block removed
>
http://osdir.com/ml/discuss-gnuradio-gnu/2010-01/m
Thanks for the reply George. I'm still looking for a little more
information on this topic.
- What is PMT
- Why was m-block removed
- Has anyone measured latency with the USRP2 and GigE
- Is GigE alone not capable of handling MAC turnaround times or is
software to blame for this
- Is the scheduler
Dear All,
I have a TVRX board, and am trying to do some experiments with it. My
requirement is to scan the entire spectrum (50MHz - 860MHz), and dump the
samples for processing using MATLAB. At a time, I am sensing 250KHz of
spectrum (decimation 256), and I am collecting 10,000 samples (40 ms sens
Hi all,
I'm trying to combine both sensing program (usrp_spectrum_sense.py) and
transmitting program, the initialization is done using the classes
usrp_options, generic_usrp, usrp_receive_path, receive_path
But when i try to pass the usrp_source_c object to spectrum sensing program
to set its
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