[srslte-users] MIMO and srsUE

[Andrés García Saavedra]

Thanks for the tips. Will try that.

Best,
Andres

On Thu, Oct 19, 2017 at 4:04 PM, Ismael Gomez <
ismael.gomez at softwareradiosystems.com> wrote:

> There seem to be buffer overflows in the USRP. That's a sign that the CPU
> can't keep up with the processing. You can see in the ue.log a few Warning
> Overflow.
>
> Since you are doing 2x2 at 20 MHz, which is the most demanding
> configuration, you need to make sure that:
>
> - You have a powerful enough CPU, i7 quad-core 3 GHz at least
> - set expert.nof_phy_threads=3 in ue.conf to run 3 threads for the PHY
> - set rf.device_args = "otw_format=sc12" to use 12-bit over-the-wire
> format for the USRP
>
>
>
>
>
>
>
> On Thu, 19 Oct 2017 at 17:48 Andrés García Saavedra <
> andres.garcia.saavedra at gmail.com> wrote:
>
>> Hi,
>>
>> Yes, sorry forgot to mention, yes, we did set nof_rx_antennas=2 in the
>> ue.conf.
>>
>> Andres
>>
>> On Thu, Oct 19, 2017 at 3:21 PM, Ismael Gomez <ismael.gomez@
>> softwareradiosystems.com> wrote:
>>
>>> Hi Andres,
>>>
>>> Have you set nof_rx_antennas=2 in the ue.conf?
>>>
>>> On Thu, 19 Oct 2017 at 16:51 Andrés García Saavedra <
>>> andres.garcia.saavedra at gmail.com> wrote:
>>>
>>>> Hi all,
>>>>
>>>> We are trying to test the 2x2 MIMO setup of srsUE and we are having
>>>> issues.
>>>>
>>>> We are using the latest code from the git repository (up to today). We
>>>> are using an USRP b210 for srsUE and a commercial LTE base station from
>>>> spidercloud Wireless. We are using plain air in band 7 (which we have a
>>>> licensed for).
>>>>
>>>> If we plug in 2 antennas on one RF Chain A of the USRP the attachment
>>>> works well and we achieve around 70Mb/s of downlink throughput as expected
>>>> for a SISO setup. UE log can be found here
>>>> <https://www.dropbox.com/s/xttw1s8wg4pkg7l/ue-1RX%20antenna.log?dl=0>
>>>> (there is an error notifying that TM 3 is not supported by the UE which is
>>>> expected as we dont have antennas on the RF chain B).
>>>>
>>>> If we now add 2 more antennas to RF Chain B and repeat the process we
>>>> have plenty of "Sync error. Sending out-of-sync to RRC" messages and
>>>> therefore the attachment procedure fails, as shown in the ue.log file
>>>> here
>>>> <https://www.dropbox.com/s/d7xutmasglirk22/ue-2RX%20antenna.log?dl=0>.
>>>>
>>>> Somebody has experienced a similar problem or have some suggestion?
>>>>
>>>> Thanks!
>>>> Andres
>>>> _______________________________________________
>>>> srslte-users mailing list
>>>> srslte-users at lists.softwareradiosystems.com
>>>> http://www.softwareradiosystems.com/mailman/listinfo/srslte-users
>>>>
>>>
>>
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