Re: [Discuss-gnuradio] [USRP-users] Multi channel transmission reception using USRP N210/GNURadio

On 11/20/2016 01:49 PM, Damindra Bandara wrote:

Dear Marcus,

Thank you very much for the quick response.

Is it possible for you to give me some more details about what I should do to transmit and receive multiple channels using N210+WBX?

Regards,

Damindra

Well, the N210+WBX has only enough hardware for a single analog TX channel.    If you carriers are close enough in frequency that they
  can be encompassed in a digital baseband bandwidth the fits your application, then this becomes more of a "how do I mux multiple
  baseband carriers on the DSP side", in which case, this is MUCH more appropriate for the discuss-gnuradio mailing list, and not here.

I have taken the liberty of cross-posting this reply to the discuss-gnuradio mailing list, which I encourage you to subscribe to.

On Sun, Nov 20, 2016 at 1:44 PM, Marcus D. Leech via USRP-users <usrp-users@lists.ettus.com> wrote:

On 11/20/2016 01:37 PM, Damindra Bandara via USRP-users wrote:

Hi,

I am trying to implement a multi channel transmitter and a receiver using GNURadio+ Ettus USRP N210+WBX board. Initially I developed a simple transmitter with two transmit channels. In USRP sink block I choose the number of channels to 2 and set the specifications for the two channels. When I try to run the flowgraph I got the following error.

RuntimeError: LookupError: IndexError: multi_usrp: TX channel 1 out of range for configured TX front ends

When I searched this online, I read that it is a problem with the  subdev specifications. I tried to set the subdev specifications to [A:AB]. However it gave the following error.

  A:AB is not a valid tx subdevice specification on mboard 0.
  possible values are: [A:0].

I appreciate if you could give me some guidance to solve this problem.  Print screen of the flowgraph is attached herewith.

Thank you,

Damindra

--

Damindra Savithri Bandara,

Ph.D. in Information Technology (Candidate)
George Mason University,
Fairfax,
Virginia

A single N210 + WBX only has a single TX channel, so your configuration cannot work as-is.

Further, the lowest possible sample rate of an N210 is 100e6/512 == 195312.5 SPS.  So, you'll have to re-sample your baseband stream as
  appropriate.

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--

Damindra Savithri Bandara,

Ph.D. in Information Technology (Candidate)
George Mason University,
Fairfax,
Virginia