[USRP-users] UBX coherence between TX and RX

Marcus D. Leech patchvonbraun at gmail.com
Wed Mar 27 16:58:12 EDT 2019


On 03/27/2019 04:48 PM, Michael R. Freedman wrote:
>
> This is on a single UBX card within a single USRP.
>
>
> ./uhd_usrp_probe --args=addr=192.168.40.100
> [INFO] [UHD] linux; GNU C++ version 7.3.0; Boost_106501; 
> UHD_3.14.0.0-0-unknown
> [INFO] [X300] X300 initialization sequence...
> [INFO] [X300] Maximum frame size: 8000 bytes.
> [INFO] [X300] Radio 1x clock: 200 MHz
> [INFO] [0/DmaFIFO_0] Initializing block control (NOC ID: 
> 0xF1F0D00000000000)
> [INFO] [0/DmaFIFO_0] BIST passed (Throughput: 1320 MB/s)
> [INFO] [0/DmaFIFO_0] BIST passed (Throughput: 1294 MB/s)
> [INFO] [0/Radio_0] Initializing block control (NOC ID: 0x12AD100000000001)
> [INFO] [0/Radio_1] Initializing block control (NOC ID: 0x12AD100000000001)
> [INFO] [0/DDC_0] Initializing block control (NOC ID: 0xDDC0000000000000)
> [INFO] [0/DDC_1] Initializing block control (NOC ID: 0xDDC0000000000000)
> [INFO] [0/DUC_0] Initializing block control (NOC ID: 0xD0C0000000000000)
> [INFO] [0/DUC_1] Initializing block control (NOC ID: 0xD0C0000000000000)
>   _____________________________________________________
>  /
> |       Device: X-Series Device
> |     _____________________________________________________
> |    /
> |   |       Mboard: X310
> |   |   revision: 6
> |   |   product: 30410
> |   |   mac-addr0: 00:80:2f:0a:ff:98
> |   |   mac-addr1: 00:80:2f:0a:ff:99
> |   |   gateway: 192.168.10.1
> |   |   ip-addr0: 192.168.10.100
> |   |   subnet0: 255.255.255.0
> |   |   ip-addr1: 192.168.20.100
> |   |   subnet1: 255.255.255.0
> |   |   ip-addr2: 192.168.30.100
> |   |   subnet2: 255.255.255.0
> |   |   ip-addr3: 192.168.40.100
> |   |   subnet3: 255.255.255.0
> |   |   serial: F5BE45
> |   |   FW Version: 6.0
> |   |   FPGA Version: 35.1
> |   |   FPGA git hash: 4c165a5
> |   |   RFNoC capable: Yes
> |   |
> |   |   Time sources:  internal, external, gpsdo
> |   |   Clock sources: internal, external, gpsdo
> |   |   Sensors: ref_locked
> |   |     _____________________________________________________
> |   |    /
> |   |   |       RX Dboard: A
> |   |   |   ID: UBX-40 v2 (0x007c)
> |   |   |   Serial: 313C181
> |   |   | _____________________________________________________
> |   |   |    /
> |   |   |   |       RX Frontend: 0
> |   |   |   |   Name: UBX RX
> |   |   |   |   Antennas: TX/RX, RX2, CAL
> |   |   |   |   Sensors: lo_locked
> |   |   |   |   Freq range: 10.000 to 6000.000 MHz
> |   |   |   |   Gain range PGA0: 0.0 to 31.5 step 0.5 dB
> |   |   |   |   Bandwidth range: 40000000.0 to 40000000.0 step 0.0 Hz
> |   |   |   |   Connection Type: IQ
> |   |   |   |   Uses LO offset: No
> |   |   | _____________________________________________________
> |   |   |    /
> |   |   |   |       RX Codec: A
> |   |   |   |   Name: ads62p48
> |   |   |   |   Gain range digital: 0.0 to 6.0 step 0.5 dB
> |   |     _____________________________________________________
> |   |    /
> |   |   |       RX Dboard: B
> |   |   |   ID: UBX-40 v2 (0x007c)
> |   |   |   Serial: 313C191
> |   |   | _____________________________________________________
> |   |   |    /
> |   |   |   |       RX Frontend: 0
> |   |   |   |   Name: UBX RX
> |   |   |   |   Antennas: TX/RX, RX2, CAL
> |   |   |   |   Sensors: lo_locked
> |   |   |   |   Freq range: 10.000 to 6000.000 MHz
> |   |   |   |   Gain range PGA0: 0.0 to 31.5 step 0.5 dB
> |   |   |   |   Bandwidth range: 40000000.0 to 40000000.0 step 0.0 Hz
> |   |   |   |   Connection Type: IQ
> |   |   |   |   Uses LO offset: No
> |   |   | _____________________________________________________
> |   |   |    /
> |   |   |   |       RX Codec: B
> |   |   |   |   Name: ads62p48
> |   |   |   |   Gain range digital: 0.0 to 6.0 step 0.5 dB
> |   |     _____________________________________________________
> |   |    /
> |   |   |       TX Dboard: A
> |   |   |   ID: UBX-40 v2 (0x007b)
> |   |   |   Serial: 313C181
> |   |   | _____________________________________________________
> |   |   |    /
> |   |   |   |       TX Frontend: 0
> |   |   |   |   Name: UBX TX
> |   |   |   |   Antennas: TX/RX, CAL
> |   |   |   |   Sensors: lo_locked
> |   |   |   |   Freq range: 10.000 to 6000.000 MHz
> |   |   |   |   Gain range PGA0: 0.0 to 31.5 step 0.5 dB
> |   |   |   |   Bandwidth range: 40000000.0 to 40000000.0 step 0.0 Hz
> |   |   |   |   Connection Type: QI
> |   |   |   |   Uses LO offset: No
> |   |   | _____________________________________________________
> |   |   |    /
> |   |   |   |       TX Codec: A
> |   |   |   |   Name: ad9146
> |   |   |   |   Gain Elements: None
> |   |     _____________________________________________________
> |   |    /
> |   |   |       TX Dboard: B
> |   |   |   ID: UBX-40 v2 (0x007b)
> |   |   |   Serial: 313C191
> |   |   | _____________________________________________________
> |   |   |    /
> |   |   |   |       TX Frontend: 0
> |   |   |   |   Name: UBX TX
> |   |   |   |   Antennas: TX/RX, CAL
> |   |   |   |   Sensors: lo_locked
> |   |   |   |   Freq range: 10.000 to 6000.000 MHz
> |   |   |   |   Gain range PGA0: 0.0 to 31.5 step 0.5 dB
> |   |   |   |   Bandwidth range: 40000000.0 to 40000000.0 step 0.0 Hz
> |   |   |   |   Connection Type: QI
> |   |   |   |   Uses LO offset: No
> |   |   | _____________________________________________________
> |   |   |    /
> |   |   |   |       TX Codec: B
> |   |   |   |   Name: ad9146
> |   |   |   |   Gain Elements: None
> |   |     _____________________________________________________
> |   |    /
> |   |   |       RFNoC blocks on this device:
> |   |   |
> |   |   |   * DmaFIFO_0
> |   |   |   * Radio_0
> |   |   |   * Radio_1
> |   |   |   * DDC_0
> |   |   |   * DDC_1
> |   |   |   * DUC_0
> |   |   |   * DUC_1
>
>
>
> Mike
>
OK, so could you use the tx_waveforms example in multi-channel mode and 
confirm correct output on a spectrum analyser,
   or another X310 doing receive?


>
>
> On 03/27/2019 03:42 PM, Marcus D. Leech via USRP-users wrote:
>> On 03/27/2019 03:39 PM, Michael R. Freedman via USRP-users wrote:
>>>
>>> Marcus,
>>>
>>>
>>> I tried a 10MHz LOOffset with no change.  I also tried it at 
>>> 1155.0MHz and 1160.0MHz.  At 1155 the phase rolls... at 1160 it does 
>>> not.
>>>
>>>
>>> Mike
>>>
>> Could you give us a dump of uhd_usrp_probe for an X310 that displays 
>> this issue?  What version of UHD?   Also, to be clear, this is within
>>   a *single* X310, correct?
>>
>>
>>>
>>> On 03/27/2019 11:10 AM, Marcus D. Leech via USRP-users wrote:
>>>> On 03/27/2019 10:41 AM, Michael R. Freedman via USRP-users wrote:
>>>>>
>>>>> Any thoughts on this?
>>>>>
>>>>>
>>>>> Mike
>>>>>
>>>> Given that in this case, the incoming carrier will be fighting 
>>>> DC-offset removal rather hard, I wonder if this is a weird artifact 
>>>> of DC-offset
>>>>   removal?
>>>>
>>>> If you use offset tuning on the RX, do you still see a significant 
>>>> phase roll?
>>>>
>>>>
>>>>>
>>>>> On 03/25/2019 01:04 PM, Michael R. Freedman via USRP-users wrote:
>>>>>>
>>>>>> Marcus,
>>>>>>
>>>>>>    190Hz is what we calculated.  I have attached a text file with 
>>>>>> the data we used.  This is a single UBX40 tuned to 155MHz 
>>>>>> sampling at 2MHz.
>>>>>>
>>>>>>
>>>>>> Mike
>>>>>>
>>>>>>
>>>>>> On 03/25/2019 12:34 PM, Nick Foster wrote:
>>>>>>> Well, according to your description, you could transmit a 
>>>>>>> carrier from TX to RX (through an attenuator) with both sides 
>>>>>>> set to the same frequency. Your received signal should look like 
>>>>>>> a sine wave at the frequency of the offset.
>>>>>>>
>>>>>>> On Mon, Mar 25, 2019 at 9:16 AM Michael R. Freedman via 
>>>>>>> USRP-users <usrp-users at lists.ettus.com 
>>>>>>> <mailto:usrp-users at lists.ettus.com>> wrote:
>>>>>>>
>>>>>>>     Hello,
>>>>>>>
>>>>>>>     Do you have any suggestions as to how to measure the
>>>>>>>     frequency delta between the transmit channel and the receive
>>>>>>>     channel?
>>>>>>>
>>>>>>>     As I sat down to do this, I realized I have no real way to
>>>>>>>     do that.
>>>>>>>
>>>>>>>
>>>>>>>     Mike
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>     On 03/24/2019 03:23 PM, Marcus D. Leech via USRP-users wrote:
>>>>>>>>     On 03/24/2019 02:39 PM, Freedman, Michael - 1008 - MITLL
>>>>>>>>     via USRP-users wrote:
>>>>>>>>>     It is not just a phase offset. It is a frequency offset. The phase drifts between the two. I can tolerate a phase offset at startup. A freq offset however is causing problems.
>>>>>>>>>
>>>>>>>>>     Mike
>>>>>>>>>
>>>>>>>>>     Sent from my iPhone
>>>>>>>>>
>>>>>>>>>     On Mar 24, 2019, at 4:28 AM, Marcus Müller<marcus.mueller at ettus.com>  <mailto:marcus.mueller at ettus.com>  wrote:
>>>>>>>>>
>>>>>>>>>     Can you elaborate on what "not coherent" means to you – the relative
>>>>>>>>>     phase should be constant after each tune, but if you don't tune
>>>>>>>>>     simultaneously, i.e. with timed commands, random at each tune.
>>>>>>>>>
>>>>>>>>>     Best regards,
>>>>>>>>>     Marcus
>>>>>>>>     Also, what version of UHD?  What hardware rev of UBX cards?
>>>>>>>>
>>>>>>>>
>>>>>>>>>     On Sat, 2019-03-23 at 17:06 -0400, Michael R. Freedman via USRP-users
>>>>>>>>>     wrote:
>>>>>>>>>>     Hello,
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>     I have an issue where I tune both the TX and RX side of a UBX40 card
>>>>>>>>>>     in
>>>>>>>>>>     an X310 to the same frequency and find that the transmitted signal
>>>>>>>>>>     and
>>>>>>>>>>     what is received are not coherent.  I am using an external 10MHz
>>>>>>>>>>     reference and have tried the documented suggestions.
>>>>>>>>>>
>>>>>>>>>>     at 150MHz it is coherent.
>>>>>>>>>>
>>>>>>>>>>     at 155MHz it is NOT coherent.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>     I have tried setting the dboard_clock_rate to 20MHz.  This made the
>>>>>>>>>>     problem appear at 150MHz as well.  I've tried integer_n tuning.
>>>>>>>>>>
>>>>>>>>>>     I have verified that the ref_lock and lo_lock are both true.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>     Any suggestions?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>     Mike
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>     _______________________________________________
>>>>>>>>>>     USRP-users mailing list
>>>>>>>>>>     USRP-users at lists.ettus.com  <mailto:USRP-users at lists.ettus.com>
>>>>>>>>>>     http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>     _______________________________________________
>>>>>>>>>     USRP-users mailing list
>>>>>>>>>     USRP-users at lists.ettus.com  <mailto:USRP-users at lists.ettus.com>
>>>>>>>>>     http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>     _______________________________________________
>>>>>>>>     USRP-users mailing list
>>>>>>>>     USRP-users at lists.ettus.com  <mailto:USRP-users at lists.ettus.com>
>>>>>>>>     http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>>>>>>
>>>>>>>     _______________________________________________
>>>>>>>     USRP-users mailing list
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>>>>>>>     http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> USRP-users mailing list
>>>>>> USRP-users at lists.ettus.com
>>>>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
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>>>>
>>>>
>>>>
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>>>
>>>
>>>
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>>
>>
>>
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