Re: [Discuss-gnuradio] QPSK Receiver and Processing Power

Thanks Stephan, that was a very good point to make. I have reduce the number of taps in my equalizer.

Unfortunately, this hasn't fixed the issue I spoke of (surprisingly). I am seeing dropped packets at sample rates of 200k, on and off, and HUGE latency between making a change at the transmitter and seeing it at the receiver. I am beginning to suspect an underlying network issue. My setup is an old cheap gigabit switch which connects two N210's to my laptop. I think something in that domain isn't performing as it should. I will dig further.

v/r,

Rich

On Thu, Feb 19, 2015 at 12:01 AM, Ludwig Stephan (CR/AEH4) <Stephan.Ludwig2@de.bosch.com> wrote:

Hello Rich,

 

although Ed commented on the latency issue, regarding your performance issue my 2 pence: From my experience, using a time domain equalizer with 100 taps is a huge computational burden. Imagine: You are expecting significant echos (to be equalized) of 100*4/250kHz=1,6 ms. I do not know your application, but for wireless this is a whole lot.

 

BTW: I am about to use exactly your computer USRP setup.

 

Best regards

Stephan Ludwig

Robert Bosch GmbH
Corporate Sector Research & Advance Engineering, Communication Technology (CR/AEH4)
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Von: discuss-gnuradio-bounces+stephan.ludwig2=de.bosch.com@gnu.org [mailto:discuss-gnuradio-bounces+stephan.ludwig2=de.bosch.com@gnu.org] Im Auftrag von Richard Bell
Gesendet: Donnerstag, 19. Februar 2015 00:45
An: discuss-gnuradio@gnu.org
Betreff: [Discuss-gnuradio] QPSK Receiver and Processing Power

 

Hello all,

My question is, looking at my receiver flowgraph, would you think this design should push the limits of a good laptop? Would you believe I could be constrained to near the lowest sample rate limit with this design?

Laptop Specs: HP Elitebook 8570w, Core i7, 16 GB RAM, Ubuntu 14.04

 

I would be interested in hearing what sample rates other peoples QPSK radios run at with a USRP N210 and similar computer.

Thanks,
Rich