Hello Kyeong Su Shin Thanks very much for your kindly reply. First, the information about the software radio structure contains three kinds, which are Low-pass sampling architecture, RF direct band-pass sampling architecture, and IF band-pass sampling architecture. Among them, according to the second generation USRP structure, only the IF band-pass structure is designed for analog down-conversion.
The N210's structure(reference attachment) contains the DDC notation. And DDC contains the digital down conversion. As you mentioned the low-frequency IF stage is optional. Does this mean that the digital shifting in the IF is to adjust for the bias caused by the previous down-conversion? Or this step can be controlled by command. Kyeong Su Shin <kss...@postech.ac.kr> 于2022年11月11日周五 16:52写道： > Hello Ze Zhang: > > First, there is a dedeicated mailing list for USRP-specific questions: > USRP-users. https://kb.ettus.com/Mailing_Lists > > "the information mentioned that the common structure for all USRPs is the > IF bandpass sampling structure," -> where did you find this information? > This is, in general, not true. USRP N200/N210s, especially, usually default > to zero-IF (direct conversion) mode (not always, though). > > In case of the USRP N200s/N210s, daughterboards implement the RF/IF (if > exists) stages of the transceivers and the motherboards implement the > baseband and the digital stages of the transceivers. The daughterboards > often do not have any IF stages, and directly convert the signal to the > baseband. The motherboards CAN implement a low-frequency IF stage by > digitally shifting the baseband signals before the decimation stage. This > is optional, and not used by default. > > Regards, > Kyeong Su Shin > ------------------------------ > *보낸 사람:* Ze Zhang <zezeze...@gmail.com> 대신 > discuss-gnuradio-bounces+ksshin=postech.ac...@gnu.org > <discuss-gnuradio-bounces+ksshin=postech.ac...@gnu.org> > *보낸 날짜:* 2022년 11월 11일 금요일 오후 3:56 > *받는 사람:* discuss-gnuradio@gnu.org <discuss-gnuradio@gnu.org> > *제목:* Questions about the IF signal processing structure of USRP N210 > > > Hi, > > I am using the URSP N210, and have some questions regarding the internal > IF (intermediate frequency) signal processing structure of USRP N210. > > In the websites, the information mentioned that the common structure for > all USRPs is the IF bandpass sampling structure, and in the previous > question( > https://lists.gnu.org/archive/html/discuss-gnuradio/2013-09/msg00007.html) > it was mentioned that USRP N210 is the common second generation USRP > structure. > > So is there any difference between the second-generation USRP > structure and the digital IF transceiver structure? Also, what is the IF > frequency range of the RF signal received by the N210 after analog > down-conversion? > > Is it possible to get the value of the local oscillator frequency or the > value of IF frequency by the setting carrier frequency? > >
