I am noticing poor CINR results of around 5 to 10dB around few void areas of a shopping center, where the RSRP is better than -80dBm and there is no macro interference at these areas (Note the site is vertically sectorised - so there is no spillage between the sectors at these areas). We walk-tested the site again to make sure the scanner is working properly - but the same poor CINR levels have been noticed at the same areas. And the CINR drops for all LTE bands on the same areas too. But the SINR calculated from the UE is better than 20dB at these areas.
Could anyone please explain what other factors could affect CINR levels?
And is there any formula that I can use to calculate the SINR and CINR values? The formulas that I have found on the web does not match with the calculated values from the log-files!!
Any help would be appreciated. Cheers.