How to Calculate Reference Signal Tx Power?

4G LTE
1

Dear all,
How to calculate Reference Signal Tx power for 40 watts,10 MHz LTE system?
40 / (50 * 12 * 14)?
Total power distributed among all subcarrier in frequency domain and in time domain is it among symbol level or TTI level.
Or do we need to consider only among frequency?
40 / (50 * 12)?

Admin note: this post was updated with image below.
How to Calculate Reference Signal Tx Power

1 Like
2

Correct. Assuming equal distribution, no RS Boost, etc… 18.2dBm

3

Ok.
Does it vary with no of Tx?
Say for 1T no, if reference signal REs are 4, and for 4T it is 12. How this impact reference signal Tx power?

4

By adding Tx paths you add some gain like 3dB from 1T to 2T in DL and same for Rx paths too.

5

Sure, you must consider your MIMO config, the amount of Watts per antenna port? Usually when you deploy 4x4 you double the PA power.
Not mandatory, but rule of thumb.

6

Doubling the PA power to ensure power per branch in 4×4 remain same as 2×2.
Is that correct?

7

This calculator might be useful:

*available in our Coummunity here: Resources & Links

8

Thank You.
Whether MIMO will double the Total Tx power?
Suppose my reference signal Tx power is 18.2 dbm for 2TX, 10MHz, 40 Watts total power.
What may be the reference signal Tx power for 4TX?

9

It’s 3 dB less in 4TX compared to 2TX, like Pa is -3 in 2TX then in 4TX Pa is -6.

10

In Huawei you put directly the RS power by dBm, and then you are calculating the power/per (Watt) by (RS , Pa, Pb, and BW). Then calculate the total power depending on number of port , either 2x2 or 4x4.

In Nokia you configure power/port by, and from it you are calculating the RS by dlrsboost parameter.

11

In Nokia, If I am not using dlrsboost (dlrsboost as zero dB), then power per port distributed among all subcarriers right?
Ie 40 / (50 * 12) = 18 dBm?
.

12

dlrsboost is not on/off switch, you configure it by values 700 till 1300 (-3dB till 3 dB).

If you set it to 1000 ( 0 dB), then you are not boosting the RS compared to the other REs.

14

I have made one sheet for my reference to calcuate the RS Power in LTE. Try it out and let me know if it works for you
RS Power Calculator.xlsx (22.1 KB)

5 Likes
15

Thanks, I went through this:

But I need some more details, if any expert can help.