Re: [Discuss-gnuradio] Any way to sample/log the 50Mhz ISM signal in gnuradio with USRP2?

On 07/11/2014 10:20 PM, Yingjie Chen wrote:

Hi guy,

Thanks in advance.

Currently I am implementing a project based on ofdm_bentchmark  example with USRP2. I remember that the sample rate of ADC of USRP 2 with RF2450 can be up to 100MS/s. That means we can use USRP2 to capture at most 50Mhz bandwidth signal. 

Initially, I plan to log the signal on my computer (save as dat. format) and analyze it offline. Everything is fine when the sample rate(bandwidth) is set to 20MS/s in terminal. However, when we set the sample rate up to 50MS/s, nothing can be log in my computer. I guess there some software limitations in Gnuradio. 

My question is how to remove such limitation to achieve the 50MS/s sample rate. Any help will be greatly appreciated.

Best, 

Kay

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To achieve 50Msps, you'll need to use 8-bit wire format, and set the peak= parameter appropriately.  There's just not enough bits/second on a
  1GiGe link to support 50Msps with 16-bit, full-width samples.

But you also need to consider the format you're writing samples to disk in, and how much disk-write bandwidth you'll require to support that.
   If you just use the same format (2 x 8bits) into the file, that's 100Mbyte/second into the disk.  That may or may not be supportable on your
   particular system.