Hi Experts,
Recently we have upgraded some FDD sites from 2T2R (2CRS) to 4T4R(4CRS).
The CRS power has reduced by 3 dB.
To compensate this loss, we have reduced the A2 threshold by 3 dB.
But there is still significant reduction in users.
Can you figure out what is the root cause?
Huawei, LTE.
If your pa and pb is zero, then for power booster to increase RS power pa as minus 3 and pb as 1 to increase RS power to same, but your throughput chanel will be affected. And is your max TX power the same as per RRU available?
Initial Configuration: 2x20W ( Pa=-3, Pb=1)
Now: 4x10W (Pa=-3, Pb=1)
Ok.
Change crs port to 2 again and monitor user throughput,volume and traffic.
And your rank KPI.
Does we have this relevant to Nokia?
But we have reduced the A2 threshold by 3dB.
Still no improvement in user count.
CRS is reduced 3 db → coverage is smaller → fewer users.
Check the reference signal, in Hedex.
Initial Configuration (10 MHz): RS power 18.2 dBm, Data Power in B type symbol: 15. 2 dBm
Current Configuration: RS power 15.2 dBm, Data Power in B type symbol: 12.2 dBm
To compensate this loss of CRS power, we have reduced the A2 threshold by 3 dB.
But there is still significant reduction in users.
Can you figure out what is the root cause.
This is mean your users are mostly served on the edge of the cell.
Maybe…
Any other observation?
Check timing advance before and after implementing.
How much your coverage reduced.
If you implement 4T4R too and keep crs port as 2, it won’t affect user that much.
RS power is reduced because of power split in RRU.
We need to improve the CQI.
How to use 4T4R with 2 CRS ports?
In Huawei you can keep CRS port number as 2, maybe some traffic come up.
Antenna port 0 and 2 will transmit one CRS.
Antenna port 1 and 3 will transmit other CRS.
CQI may be affcted by CRS port 2.
Ok, it’s just 2 layers. 
Yes, that’s why we changed to 4 CRS.
Yes.