And to add, the possible bandwidth is even 61.44 MHz with the B210. The attenuation at the band edges gets a bit higher with this mode, and it is not too clearly mentioned in the AD9361 specs, but I am using the B210 with this setting and have no issues with it. This clock appears being a tribute to LTE demands, based on the typical 30.72 MHz from LTE.
However 56 MHz are just fine for GSM bands with the typical 45 MHz shift between uplink and downlink. Just handling the amount of data may be a problem :) Ralph. From: USRP-users [mailto:usrp-users-boun...@lists.ettus.com] On Behalf Of Marcus Müller via USRP-users Sent: Wednesday, August 30, 2017 10:33 AM To: usrp-users@lists.ettus.com Subject: Re: [USRP-users] Capturing GSM downlink and uplink signal with USRP B210 Dear Erik, in general: No, but in a specific Up/Downlink scenario, it might work. To explain: The B210 indeed has two RX chains, but they are both mixed with the *same* LO. That means that the spectrum you get can only be within the analog bandwidth around that LO at f_RF: This figure just shows a single receive channel with a digital tuning offset of f_offset. You might imagine a second one, just with -f_offset, i.e. to the left of f_RF. At the most, you could cover a piece of spectrum that is b_analog wide. That b_analog is adjustable on the B210, but it's limited on the upper end to 56 MHz. So, if the lowest channel of your Uplink and the highest channel of your Downlink fit within 56 MHz, you're fine, and this is theoretically possible (still have to choose sampling rates that work for the 56 MHz analog bandwidth, and still have to have a USB3 controller strong enough to not break down under heavy load if the combined load of your two RX channels are rushing through it)! So: that's an "it depends, but in many cases, it might work"! Best regards, Marcus On 30.08.2017 10:16, erik via USRP-users wrote: Hi List, I would like to capture GSM downlink and uplink signals with USRP B210. I have done this previously with 2 units of USRP and connected via MIMO cable. My question, is it possible to perform this activity with USRP B210, which already have 2 RF channels and do i have to add additional clock source or is it enough with USRP B210? Thanks and best regards, Erik _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com <mailto:USRP-users@lists.ettus.com> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
_______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
