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Today's Topics:
1. Re: Data length of USRP2 receiver in Matlab simulink
(Mike McLernon)
2. Gen 2 RFID in gnuradio (Vijay Pillai)
3. How to build USRP2 binary for BASIC RX/TX from scratch
(Uzair Rauf)
4. Lost contact with USRP (Farhad Abdolian)
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Message: 1
Date: Wed, 9 Mar 2011 21:53:44 +0000
From: Mike McLernon <[email protected]>
To: yqluo <[email protected]>
Cc: "[email protected]" <[email protected]>
Subject: Re: [USRP-users] Data length of USRP2 receiver in Matlab
simulink
Message-ID:
<e3879be9a282cb45aab7ce258a9ae48f071...@exmb-01-ah.ad.mathworks.com>
Content-Type: text/plain; charset="us-ascii"
Hi Yuanqian,
Can you send a model?
Mike
From: [email protected] [mailto:[email protected]] On Behalf Of yqluo
Sent: Wednesday, March 09, 2011 1:53 PM
To: Mike McLernon
Cc: [email protected]
Subject: Re: [USRP-users] Data length of USRP2 receiver in Matlab simulink
Hi, Mike:
I have tried your suggestions on multi-rate FIR filter to change data length
and rate simultaneously. However, when I add the corresponding FIR filter at
the receiver part, the received signal suffers lots of errors.
For example, FIR rate converter with mfilt.firsrc(358,96) is implemented in
sender, and FIR filter with mfilt.firsrc(96,358) is in the receiver (as a
simple case, I do it in simulink system without usrp2 modules). But the error
rate is too high in this structure.
Is there anything wrong with the design of FIR rate converter at the receiver?
Any help will be really appreciated.
On Wed, Feb 2, 2011 at 3:00 PM, Mike McLernon
<[email protected]<mailto:[email protected]>> wrote:
Hi Yuanqian,
Good questions - see responses below . . .
From: [email protected]<mailto:[email protected]>
[mailto:[email protected]<mailto:[email protected]>] On Behalf Of yqluo
Sent: Thursday, January 27, 2011 4:38 PM
To: Mike McLernon
Cc: [email protected]<mailto:[email protected]>
Subject: Re: [USRP-users] Data length of USRP2 receiver in Matlab simulink
Hi, Mike:
Thanks for your quick reply. I have several questions on this technique.
1. for certain transceiver system, does that mean we need to apply the
downsampling FIR filter ( 356/578) in the transmitter part, and then use
upsampling FIR filter (578/356) in the receiver to change the frame length back?
I believe the actual numbers are 358 and 576, but you have the idea correct.
2. do we need to consider about the effect of time-offset of FIR filter? since
FIR filter in this case should have very large order grade.
It depends on what you want to do with the signal. If you are using it to
transmit audio, and you don't care about a small delay, then you don't need to
worry about it. If the model needs to transmit digitally modulated signals,
then you may need to compensate for the effect. However, if you have a
standalone receiver model, then you will need to perform synchronization using
only the received data, and the filter delays shouldn't matter.
3. how to deal with the situation that the data rates diverse greatly? i.e., if
we need 1000/356 upsampling, then FIR filter may not work in this situation. I
think the rebuffering may be the only solution in this case.
If you can avoid the rebuffering, please do. Remember that you can start with
an arbitrary frame size, and use resampling as necessary to create the length
358 frame. I've attached a model, mResmplingForUSRP.mdl, that does this with
the USRP Transmitter block.
Hth,
Mike
Really appreciate your help.
Regards,
On Thu, Jan 27, 2011 at 4:41 AM, Mike McLernon
<[email protected]<mailto:[email protected]>> wrote:
Hi Yuanqian,
We empirically found that rebuffering to change frame size in models with USRP
I/O blocks severely degraded real-time performance. You'll note in our FM
demos that we do not perform any rebuffering, so that we can keep the model
single rate in Simulink.
However, if you can be flexible on your sample rate, I can show you a technique
so that you can get a frame size of 576 while still keeping the model single
rate in Simulink. You would use resampling filters to change the size of the
frame. Take a look at the FM demos to see how this is done - turn on the
display of signal dimensions, and it should become clear. If not, I can show
you a simple model that converts a frame size of 358 to one of 576 while
keeping the Simulink model single rate.
Best,
Mike
From:
[email protected]<mailto:[email protected]>
[mailto:[email protected]<mailto:[email protected]>]
On Behalf Of yqluo
Sent: Wednesday, January 26, 2011 8:27 PM
To: [email protected]<mailto:[email protected]>
Subject: [USRP-users] Data length of USRP2 receiver in Matlab simulink
Hi, everyone:
I have tried to modify the transceiver parts of USRP2 model in the Matlab
simulink environment. I want to change the receiver data length to 576 instead
of 358 to match the receiver design. But after changing the value, there is no
signal received at all.
Here is what i did:
1. Disable link at "Link option", and then break the link. (in order to change
the length value)
2. change the packet length and data length to 576.
I am not sure whether the received data length in the USRP2 receiver model can
be changed or not? Is there any user manual to show how to modify the USRP2
model in simulink?
Regards,
--
Yuanqian Luo
Department of Electrical and Computer Engineering
University of Victoria
--
Yuanqian Luo
Department of Electrical and Computer Engineering
University of Victoria
--
Yuanqian Luo
Department of Electrical and Computer Engineering
University of Victoria
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Message: 2
Date: Wed, 9 Mar 2011 22:23:48 -0800 (PST)
From: Vijay Pillai <[email protected]>
To: [email protected]
Subject: [USRP-users] Gen 2 RFID in gnuradio
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
I came across the following site that apparently implemented a Gen2 UHF rfid
reader using a USRP. However accessing the website on firefox gave me the
warning that this is an untrustworthy site or something to that effect.
https://www.cgran.org/wiki/Gen2
Does anyone know if this is a legit website?
Best regards,
-Vijay
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Message: 3
Date: Thu, 10 Mar 2011 12:25:52 +0500
From: Uzair Rauf <[email protected]>
To: [email protected], Farooq Shah <[email protected]>,
Farooq Shah <[email protected]>
Subject: [USRP-users] How to build USRP2 binary for BASIC RX/TX from
scratch
Message-ID:
<[email protected]>
Content-Type: text/plain; charset="iso-8859-1"
Hi
I am a student who is working on the radar signal processing project using
custom firmware, retaining as much of the original code as we can. To wet my
feet, I must build the binaries for USRP2 for BASIC RX/TX from scratch. I
got the git but am somewhat lost in the maze. I need to know which is the
top level makefile which builds the entire project OR perhaps a bunch of
makefiles that build parts of it. Also the process of going from the coed to
the files to be burned on the SD. I do have xilinx ISE12.4.
Uzair Raoof
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Message: 4
Date: Thu, 10 Mar 2011 08:25:39 -0800 (PST)
From: Farhad Abdolian <[email protected]>
To: [email protected]
Subject: [USRP-users] Lost contact with USRP
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
Hi,
I have a USRP1 that was working fine, but I can no longer communicate with it.
Is there anywhere I can diagnose the problem?
Thanks in advance,
/Farhad
PS. I am using Ubunto 10.10
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