Hi all, Looking at implementing a TDMA like system with UHD and I'm interesting in qualifying what constraints or limitations exist w.r.t. AD9361 based devices. From my look into the code, UHD places the AD9361 FDD mode with both chains enabled and basically always receives samples unless a burst of transmit data is sent, which will also activate a TX/RX RF switch. So in comparison with the AD9361 TDD mode, we shouldn't have to worry about delays caused by bringing the chains back online like ADC turn on delay, VCO calibration delay, etc.
Despite this I'm guessing there is still some significant amount of delay in transitioning from the TX to RX states and vice versa.. As a first stab at this, on an E310 I used the tx_bursts UHD example script at a 2MSps rate sending 100 sample bursts, I continually reduced the repetition rate down until it no longer had an effect, at this point scoping the output showed about 70 microseconds between transmit bursts. Not sure if this is reasonable or the best way to go about this, but ideally I'd like to figure out limitations on how small slots can realistically be and how much guard time should be allocated to the transition delay (of course this delay should hopefully be much smaller than the guard needed for errors in the node clock synchronization). thanks, Michael _______________________________________________ USRP-users mailing list USRP-users@lists.ettus.com http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
