# High Precision ISM Band Spectrum Recording with USRP N210

**URL:** <https://www.ruby-forum.com/t/high-precision-ism-band-spectrum-recording-with-usrp-n210/233972>\
**Category:** GNU Radio\
**Created:** [January 27, 2015, 12:17pm UTC](https://www.ruby-forum.com/t/high-precision-ism-band-spectrum-recording-with-usrp-n210/233972 "2015-01-27T12:17:19Z")\
**Posts on this page:** 2\
**Page:** 1

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**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:** [January 27, 2015, 12:17pm UTC](https://www.ruby-forum.com/t/high-precision-ism-band-spectrum-recording-with-usrp-n210/233972/1 "2015-01-27T12:17:19Z")

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Hi All,

I have a USRP N210 with RFX2400 2.3-2.9GHZ RX/TX. I want to view the ISM  
Spectrum band from 2.40GHz - 2.48Ghz. Record it with a very high  
precision.

I have the following doubts :

1. Which port the antenna should be connected to get better accuracy ?  
TX/RX or RX. As said, I just want to record the activity the ISM band.

2. I connected the antenna to the TX/RX port, configured the center  
frequency of the USRP at 2.44Ghz and a bandwidth of 80MHz. To view the  
complete spectrum activity with an antenna gain of 30db. Can usage of  
any  
post processing block after sampling lead to higher accuracy of the  
samples  
compared to storing the raw samples ?

Thanks and Regards,  
Vaibhav

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**Author:** ![vaibhav\_kulkarni](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/5fc32e/32.png) [@vaibhav\_kulkarni](https://www.ruby-forum.com/u/vaibhav_kulkarni)\
**Post date:** [January 27, 2015, 4:08pm UTC](https://www.ruby-forum.com/t/high-precision-ism-band-spectrum-recording-with-usrp-n210/233972/2 "2015-01-27T16:08:20Z")

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On 01/27/2015 06:15 AM, vaibhav kulkarni wrote:

> 1. I connected the antenna to the TX/RX port, configured the center  
> frequency of the USRP at 2.44Ghz and a bandwidth of 80MHz. To view the  
> complete spectrum activity with an antenna gain of 30db. Can usage of  
> any post processing block after sampling lead to higher accuracy of  
> the samples compared to storing the raw samples ?
> 
> Thanks and Regards,  
> Vaibhav  
> Either port will produce nearly-identical results.

The maximum sample-rate of the N210 is 25Msps. You’ll have to piece  
together four chunks of spectrum to cover your desired 80MHz.

Also, what is it that you mean by “accuracy” in this case? Faithful  
reproduction of the amplitudes as seen at the antenna port? Faithful  
reproduction of the signals as sent by the transmitter?