Ec/No decrease after changing Power

In 3G can any one explain to me why I’m having a huge decrease in Ec/No when I rise the power of the WRFU from 40 Watt to 80 Watt without increasing the pilot?


More power, more traffic, more noise, lower Ec/no.

Ecno = CPICH / Total Power.

This equation persists for 4G?

No Ec/No in 4G.

How about the impact of increasing RF power in 4G?
I mean if we increase RF power from 40 watt to 80 watt for example.
How about the impact in terms of Coverage and Capacity?
Thanks in advance.

It’s a balance between between received RSRP and SINR.
Increasing power can enhance RSRP and SINR, and sometime it enhances RSRP but degrades SINR.

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Is there an equation or relation to prove it?

Increasing RF power will improve RSRP of own cell but it will be treated as noise for adjacent cell and will degrade performance of neighbour cells.

Does the number of UEs increase?

No, it decreased.:sweat_smile:
About 30%, that’s what confusing me.
But the HSDPA user throughput in DL increased about 50%.

I have increased the power of 4 cells in the same site.
May it be the reason of Ec/No degredation?

If we increase Pilot power coverage may get improve but Ec/No may decrease.
Instead of that to improve HSDPA performance we can keep pilot power same and can increase Total power.

Ya, it’s true and that what I was doing.
But the low EcNo surprised me with its huge degredation.
I got the opposite.

What about Throughput and data usage in those cells?

User throughput, R99 increased.

Please verify if it was the unique change performed for this site cell coverage, maybe an optimization related to its neighbors or overshooting cells had been done on other neighborcluter.
As all we know the EcNo is calculated by the energy received from others compared to cell pilot power, so if there was not change on pilot power the change should be on overall interference received.
Nevertheless by doing as you related there is more power for HSDPA which explains the throughput increasing this can be decreasing the number of connected users, depending on the inactive timer setting, since throughput incresing can help on decreasing the connected time.
Your CQI probabily was decreased, as well.

Increase RF power from 40 to 80W will overall coverage improvement in RSRP, SINR, DL throughput as well.
Overshooting will need control by adjust of E-tilt or Mtilt, Azimuth or height changes.

Better go for CRS Deboosting in such case to maintain the coverage, avoid overshoots but still utilize the maximum possible power for the shared channel.

EcNo = 10log(CPICH Power/ Total Power)
For example, if your CPICH power is fixed on 2W
So, for 40W EcNo will be -13, but for 80W EcNo will be -16