[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Help : Is this right that the daughterboard passe

From: Marcus D. Leech
Subject: Re: [Discuss-gnuradio] Help : Is this right that the daughterboard passes data to the usrp board in the I and Q format.
Date: Mon, 25 Apr 2011 09:05:57 -0400
User-agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv: Gecko/20110303 Thunderbird/3.1.9

On 25/04/2011 8:34 AM, ton ph wrote:
Hi marcus
thanks for immediate reply and your guide was very helpful from my side ... Now the question is , suppose, i have 12 bit 200 mhz adc , and i do not want to reduce my processing bit , as per the instruction from your side it could be hard to process in my i5 , 4Gb ddr3 configuration computer and also i am not aware of the IF bandwidth which might require to make the bandwidth process instantly ( simultaneously ) . Will gnuradio be able to support the instantaneous processing of the 100Mhz bandwidth,
I have a bit doubt as i learnt that gnuradio can support 8Mhz only.

Thanks , and i highly apologize if my post is a bit out of track or may be called a bit illogical ....

Thanks marcus.

I process 25MHz bandwidth from a USRP2 with my Radio Astronomy applications, on a 6-core AMD Phenom II X6 running at 3.2GHz.

The "8MHz" figure you quote is likely from the original USRP--nothing to do with Gnu Radio, per se. The USRP1 has a maximum
  bandwidth of 8MHz unless you drop down to 8-bit samples.

The computational load of a signal flow-graph is proportional to bandwidth X complexity.

If you want to process 200Msps, with full 12-bit resolution, you'll need to find some other host interface than 1GiGe--you'd likely
  need to go to a 10GiGe interface.

And while Gnu Radio "scales" arbitrarily, there are limits to the degree to which you can optimize a flow-graph for performance. The "Lego brick" approach to constructing processing graphs isn't optimal if really-high performance and low-latency are important to you. In order to process 200Msps, you'd likely need to hand-craft your signal processing chain, and carefully parallelize it in an optimal way. No way are you going to be able to do this on a single-processor machine.

Further, as you point out, the post-mixer bandwidth of the USRP-family daughtercards is limited to much less than 50MHz, in order for there not to be an aliases when sampled at the 100Msps rate of the ADC on the USRP.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]