What is the relation between CQI and Bandwidth?

Specs & Protocol Testing
1

Hi Experts.

We have reduced the LTE TDD bandwidth from 20 MHz to 15 MHz.

We observed that our CQI has reduced.

What is the relation between CQI and Bandwidth?

2

Is the TA same?

Has power reduced in same proportion?

3

BWs reduced.

So RS power increased, coverage foot print increased, UE number increased, so poor RSRP sample increased resulting in poor CQI.

4

RS power was adjusted before the activity.