# How do you improve a spectrum analysis on a USRP1? **URL:** \ **Category:** GNU Radio\ **Created:** [September 24, 2014, 10:26pm UTC](https://www.ruby-forum.com/t/how-do-you-improve-a-spectrum-analysis-on-a-usrp1/232205 "2014-09-24T22:26:11Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [September 24, 2014, 10:26pm UTC](https://www.ruby-forum.com/t/how-do-you-improve-a-spectrum-analysis-on-a-usrp1/232205/1 "2014-09-24T22:26:11Z")
I am using GNURadio with a USRP1 and would like some clarity on how the USRP1 works because I’m new to both. Because of the limited speeds of USB transmission, the USRP1 cant efficiently perform a spectrum analysis. So to analyse a large range of frequencies, GNURadio measures 8 MHz chunks by changing the center frequency and stitches the data together before performing an analysis. But constantly changing the center frequency causes a time delay before the correct samples from the ADC can be seen by the computer. Are there any better ways to do this with a USRP1? Is it possible to apply a sub-Nyquist sampling rate in hardware before transmission through USB to create a more efficient spectrum analysis? From what I understand, a sub-Nyquist sampling rate can somehow allow the reconstruction of a signal using a rate below Nyquist. If possible, this would mean more information could be transmitted through the same USB cable and fewer changes in the center frequency. Or is GNURadio’s implementation about as good as its going to get on the USRP1? I already asked ETTUS about directly controlling the hardware, and they suggested I ask the GNURadio community.