Hello Issac: USRP uses I-Q sampling (there are some exceptions, though). When I-Q sampling is used, the Nyquist bandwidth is equal to the sampling rate of the stream, not half of it. So, the theoretical bandwidth of your 25MS/s stream is 25 MHz, not 12.5 MHz. See https://wiki.gnuradio.org/index.php/IQ_Complex_Tutorial and https://dsp.stackexchange.com/questions/36927/bandwidth-with-complex-sampling for further information.
I don't know how Ettus Research came up with the 20 MHz figure. I guess they are talking about the filter characteristics. You may experience some aliasing issues at the edges of the spectrum, due to the filter characteristics. Regards, Kyeong Su Shin ________________________________ 보낸 사람: isaac mario tupac davila <[email protected]> 보낸 날짜: 2021년 5월 12일 수요일 오전 7:15 받는 사람: [email protected] <[email protected]> 제목: [USRP-users] Sampling rate and bandwidth - Usrp N210 & source block Hello community I'm Isaac. I'm dealing with some questions about the interpretation of sampling rate and bandwidth in a USRP source block. What I understand is if I work with an USRP N210, my ADC works with a 100MS/s. If I use a Gigabit Ethernet and a data type of 16bits, I could receive in my host up to 25MS/s with a bandwidth of 20MHz. https://kb.ettus.com/About_USRP_Bandwidths_and_Sampling_Rates My questions are: 1. If I can receive up to 25MS/s on my host, why my bandwidth is 20MHz? I think It is up to 12.5MHz according to Nyquist. 2. Why is the sample rate value in the usrp source block equal to the bandwidth I observe? I think this bandwidth should be the half according to Nyquist too. https://wiki.gnuradio.org/index.php/USRP_Source I appreciate any help to clarify this concepts Regards Isaac T.
_______________________________________________ USRP-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
