Re: [Discuss-gnuradio] Concurrent Rx on USRP E312

On 03/01/2018 01:04 AM, kailash kumar wrote:

Hi,

I am trying to explore the possibility of using Rx channels(0,1) independently and concurrently on Ettus USRP E312.

Here is what I am trying:

USRP 1  --> Rx Freq 1 --> Filter --> Demodulation and Decode 1 --> Audio Sink
             --> Rx Freq 2 --> Filter --> Demodulation and Decode 2 --> Audio Sink

When transmit at frequency 2, Data gets received on both Rx channels and gets processed even though center freq is different.

Attached is the flow graph.

Is it possible to use both Rx concurrently? If yes, anything that I am missing wrt flowgraph?

Thanks
Kailash

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You're missing the fact that the AD9361 front-end on the E312 uses a *shared* LO for both RX channels.  The LO physically cannot be tuned to different
  frequencies, although differences of up to 30Mhz or so can be arranged by using DSP tunings, your tunings of 96MHz and 710MHz simply cannot be
  achieved by the hardware.

Further discussion might be more useful on the usrp-users mailing list, instead of here.