On Mon, Apr 25, 2011 at 6:35 PM, Marcus D. Leech
<address@hidden> 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.