- Ask a related questionWhat is a related question?A related question is a question created from another question. When the related question is created, it will be automatically linked to the original question.
Hi expert,
Below is the ACLR test on Tx3 and Tx4 channel from customer. They used FPGA for DPD. The HW circuit design on each channel are the same, but ACLR result is different.
The yellow waveform in the figure is connected on Tx3, the ACLR is passed. The blue waveform is connected to Tx4 but ACLR is failed.
May we know what parameters in the AFE7799 we can tune or any others factors might relate to this?
Thanks,
Allan
Allan,
The customer can check if the TX4 and ORX have worse isolation (i.e. TX to ORX isolation) than TX3 to ORX isolation. In DPD calculation, if there are additional observed signal due to poor isolation, then the DPD may not converge well as the main signal and the aggressor signal have same identity except different time delay.
From the picture above, it seems TX4 crosses ORX2. This may be the reason for the poorer isolation spec compare to TX3 to ORX2.
-Kang
Hi Kang,
Clarify the test environment, DA path/ORX path and PA module are used the same HW, only swap the transceiver port.
BR,
Adis
