Hello Experts,
RSRP, RSSI, RSRQ and SINR; how these quantities are calculated and more, much more in my latest post!
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Hello,
Hi Experts.
I am facing a problem where the difference between RSSI and RSRP (LTE) is very large at a certain area.
This should indicate interference, but it is in the middle of nowhere, at a farm, with no other cell within a 20km radius (FDD Band28).
Drive test shows good CQI also.
Is it possible to have some kind of interference on the reference block (RSRP - RSSI too far) and no interference at CQI (is it calculated over reference power or PDSCH)?
The cellsite covers over 10km, but the bad RSRP spot with the RSSI-RSRP difference is located at the farm’s offices.
All data is based on drive testing
Has anybody faced something like that?
It is hard to say exactly what type of interference.
As possible solution is to collect special counters which related to interference for each PRB block. Then to build a graph and see at which time or bandwidth interference is presented. Also try to analyse if other BS or sectors are facing an interference issues.
But anyway it’s better to start from BS checks, alarms, RRU way of working, Antennas reports and configuration, historical reports about any previous event on site etc.
Interference could vary in time and in frequency as well.
Also try special tools like Huawei Discovery or Ericsson Cognitive SW or similar.
They can help a lot. Or even to perform root cause analysis and give to you exact reason and solution
Thank you for the tips!
I’ll check on interference per RB, it might help.
BTS has already gone through cleanup.
Still have one doubt. How is CQI estimated?
Depends on SINR.
Is it estimated upon Reference Signal measurements?
Or over traffic blocks?
I think I found something.
It explains why RSRP is poor and CQI is fine.
Channel estimation may be done over CRS.
How does it sound like, my friends?
