# About USRP's Bandwidth **URL:** \ **Category:** GNU Radio\ **Created:** [November 8, 2011, 3:30pm UTC](https://www.ruby-forum.com/t/about-usrps-bandwidth/213670 "2011-11-08T15:30:49Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\ **Post date:** [November 8, 2011, 3:30pm UTC](https://www.ruby-forum.com/t/about-usrps-bandwidth/213670/1 "2011-11-08T15:30:49Z")
I’m a starter in using the USRP, it’s known that the bandwidth of USRP is 8M beacause of the USB bandwidth ,my question is the 8M refers to the Nquist Bandwith or the actual signal bandwidth?If it refers to the Nquist Bandwith, it is mean that USRP can only process the signal with 4M bandwidth,so if a signal larger than 4M, how can USRP deals with it ? ---
**Author:** ![SSS\_SSSSS\_SSS\_SSS](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/8baadc/32.png) [@SSS\_SSSSS\_SSS\_SSS](https://www.ruby-forum.com/u/SSS_SSSSS_SSS_SSS)\ **Post date:** [November 8, 2011, 3:50pm UTC](https://www.ruby-forum.com/t/about-usrps-bandwidth/213670/2 "2011-11-08T15:50:00Z")
On 11/8/11 9:29 AM, wrote: > I’m a starter in using the USRP, it’s known that the bandwidth of USRP > is 8M beacause of the USB bandwidth ,my question is the 8M refers to the > Nquist Bandwith or the actual signal bandwidth?If it refers to the > Nquist Bandwith, it is mean that USRP can only process the signal with > 4M bandwidth,so if a signal larger than 4M, how can USRP deals with it ? Because the USRP does complex samples, an 8 megasample/sec rate is enough to resolve up to 8 MHz. This is in contrast to magnitude-only real samples, where an 8 megasample/sec rate would only resolve up to 4 MHz. A qualitative way to think about it is that complex samples provide twice the data as magnitude-only real samples, providing that “factor of 2”. Nyquist will not be cheated! @(^.^)@ Ed ---
**Author:** ![SSS\_SSSSS\_SSS\_SSS](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/8baadc/32.png) [@SSS\_SSSSS\_SSS\_SSS](https://www.ruby-forum.com/u/SSS_SSSSS_SSS_SSS)\ **Post date:** [November 8, 2011, 4:03pm UTC](https://www.ruby-forum.com/t/about-usrps-bandwidth/213670/3 "2011-11-08T16:03:37Z")
On 08/11/2011 9:29 AM, 弓长张 wrote: > I’m a starter in using the USRP, it’s known that the bandwidth of USRP > is 8M beacause of the USB bandwidth ,my question is the 8M refers to > the Nquist Bandwith or the actual signal bandwidth?If it refers to the > Nquist Bandwith, it is mean that USRP can only process the signal with > 4M bandwidth,so if a signal larger than 4M, how can USRP deals with it ? USRP use complex-baseband sampling, which allows you to “cheat” Nyquist. With complex sampling, the sample-rate == bandwidth. With the very-latest UHD updates from Josh last night, 8-bit “wire format” samples are supported, which doubles the effective bandwidth-to-the-host for all the USRP platforms, meaning that USRP1 and B100 can support 16Msps maximum, and USRP2/N2XX can support 50Msps maximum. I’d like to see someone be able to “do something” with 50Msps into their host 🙂