 # How to calculate RS power?

How to calculate RS power?
If i have 20 MHz bw, by 80 W power, what will be the exact RS on the field?
Vendor is Ericsson.

Generally rs power = pmax - 10 log 10 (number of rb * 12 ) + any mimo gain.

Please use above formula and check in sib2 if value matches or not for rs power you calculated.
Pmax in dBm in above formula.

1 Like

Find EPRE in type-A symbol and then use Pa, Pb values to find RS Power.

20 MHz BW, this implies 100 RB X 12 RE -> 1,200 RE

Total power = 8 W = 80,000 mWatt
Power per RE = 80,000 /1,200 = 66.66 mWatt

Let’s say Pa = -3, this implies Reference Signal is 3 dB stronger
(In Ericsson it’s equivalent to CRsgain = 300)
3 dB means double
So RS power will be 66.66 x 2 = 133.32 mili Watt

Convert it into dbm
10 log (133.32 mW / 1 mW) = 21.24 dBm

Assuming Pb = 1
Otherwise there will be power imbalance [either over or under Utilization]

Another assumption is 2x2 MIMO enabled.

Hope you got it :)… Cheers 2 Likes

Appreciated. And how about if it have crsgain = 0?

It means RS power will be same as of EPRE.

So we calculated EPRE = 66.66 mWatt

In this case RS Power will be same i.e. 66.66 mWatt

Convert it into dBm.
10 log (66.66 mW / 1mW)
RS Pwr = 18.2386 dBm 2 Likes

Nice explanation @AbdurRehman87, thanks! 