Thanks marcus , i very much appreciate the info and has cleared many of my wrong concepts about usrp and gnuradio. As you have said , processing 100Mhz of bandwidth using gnuradio will be a bit Hard unless handcrafting the signal processing block by hand , what if I processes the 100Mhz bandwidth by a 200Mhz , 12 bit ADC and later on i choose only 10 channels out of my 100Mhz full band data , by a 32 channel DDC , in which i can access each channel data from software. Which might reduce my bandwidth entering the CPU to about for example: 350 * 10 = 3500 Khz . If i follow this trend, i could reduce much of the overhead to the CPU. But my doubt still exist, processing the 100Mhz bandwidth using gnuradio wil be possible or not ? ... Do we need high IF upto how much so as it can process 100Mhz ... ?
Thanks in advance for your genuine and helpful guide , and again i highly apologize any illogical post from my side . Thanks. On Mon, Apr 25, 2011 at 6:35 PM, Marcus D. Leech <mle...@ripnet.com> wrote: > 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. > > > > > -- Phenomenon # Life is the most precious phenomenon ever happen ... # Lets pray and give emotional strength to the innocent brave victims of japan.
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