LMS TxLO noise
alexander.chemeris at gmail.com
Sat Jul 21 07:51:06 UTC 2012
On Sat, Jul 21, 2012 at 7:03 AM, Thomas Tsou <thomastsou at gmail.com> wrote:
> I tried calibrating LO leakage cancellation again and found out that
> it wasn't calibrated enough. The settings are very sensitive and
> increasing the I and Q shifts by one made a large difference on the
This is my experience as well. Near the optimum point even change of
calibration registers by 1 makes big difference. When you're far off,
a change of a calibration register could be almost unnoticeable.
I've started adding notes about LMS calibration here:
Please write down there all useful notes about all types of
calibration we're doing.
> The RSA seems to compensate, though, because the same changes
> don't affect it at all.
How could it compensate? For RSA it should look like a genuine sine signal.
> I also tried some different frequencies. At the not useful frequency
> of 240 MHz, we are not far from target values. At 945 MHz, it is
> better than before, but still too high. The 1900 MHz band is not so
Well, we're more interested in GSM900, but this clearly shows that
there is an issue with the LMS PLL noise.
CEO, Fairwaves LLC / ООО УмРадио
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