What causes of Bad DL SINR (Bad CQI) in LTE network?

4G LTE
1

Hello Experts,

What causes of Bad DL SINR (Bad CQI) in LTE network?

2

Actually there are mainly two reasons for that bad DL CQI:

  1. In low load network (Non-BH):
  • RSRP_Overlap between serving and NBRs cells.
  • PCI Mod3 Clashes between serving & NBRs cells.
  • Bad RSRP level (less than -100)
  1. In high load network (BH) ::
  • Bad DL SINR so DL CQI due to high DL PRB consumption between serving and NBRs cells.
3

Hi Experts.

We have installed multiple LTE small cells.

Site is at 50m distance round shape.

But unable to get good SINR.

Any suggestions?

4

Bands?

5

FD1800 and TD2300.

6

You are getting bad SINR on which band?

7

In both bands.

8

Controlling the coverage overlap is going to be a challenge definitely, if the intra site distance is just 50m.

Specially FDD1800.

9

Yes.

Should I increase a3offset?

10

For LTE minimising RS power can help.

And for 5G SSB power reduction.

For SINR improvement.

11

First try to play with power, to control the overlap without creating the coverage gaps.

12

If one layer is turned off, will it be good?

13

High capacity is required.

Working on it.

14

Play with power if overshooters

15

Sure… But you can try for let’s say 30 minutes.

16

But what the design says?

I cannot believe those small cells were deployed without a minimum design in a tool like Atoll.

17

We didn’t used Atoll.

18

Did you use omni for antenna?

19

No, clip antenna with 15 dB gain.

20

Then try playing with antenna for each cell.

Alternatively, you can shutdown the even ones, so you have intercell distance of 100m.