[USRP-users] [Discuss-gnuradio] dc offset is different from unit to unit

Josh Blum josh at ettus.com
Sat Jun 2 23:05:36 EDT 2012



On 06/02/2012 07:47 PM, James Jordan wrote:
> Hi John,
> Thanks. But how to deal with rx dc offset?
> 

Long run RX DC level is subtracted out of the signal by default. You can
turn this behaviour on and off, and even freeze the average DC level at
its current value. See set_rx_dc_offset(...)

http://files.ettus.com/uhd_docs/doxygen/html/classuhd_1_1usrp_1_1multi__usrp.html

-josh

> On 6/2/12, John Malsbury <john.malsbury at ettus.com> wrote:
>> James,
>>
>> In the case of DC calibration for tx, we'd recommend running the dc
>> calibration routines provided with UHD for each unit.  The cal routines
>> make it a relatively easy process.
>>
>> In theory, if the average DC offset is non-zero you may be able to apply
>> an average correction and see some improvement - but less than a
>> per-unit calibration.  I don't have have any data on hand for an average
>> DC offset.
>>
>> I'm cross-posting to the usrp-users list, which is more oriented to USRP
>> specific questions.
>>
>> Best Regards
>> John Malsbury
>>
>>
>>
>> On 6/1/2012 8:57 PM, James Jordan wrote:
>>> Hi list,
>>> I need to compensate usrp dc offset. but the dc offset is different
>>> from unit to unit. so do I need to calibrate each unit dc offset or
>>> there is a universal value that work
>>> for each unit?
>>>
>>> Regards
>>>
>>> _______________________________________________
>>> Discuss-gnuradio mailing list
>>> Discuss-gnuradio at gnu.org
>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>>
>>
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> 
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