How should 5G cell power/max power/reference signal power be calculated?

Base station power in mobile communications is a key factor in determining wireless cell coverage and communication quality; in the 5G (NR) system base station (gNB) total power, cell power and reference signal power in addition to the BBU (baseband unit) output, but also with the antenna (Port) number and the cell bandwidth (BW) related to the calculation are as follows;

I. Reference Signal Power This is the power value measured and reported by the terminal (UE) and the total transmit power of the cell can be calculated by the following formula first for each channel power;

In the above equation:

• Maximum Transmit Power: Transmit power per single channel (in dBm);
• Reference Signal Power (Reference Signal Power): single channel per RE power (in dBm units).
• RBcell (cell bandwidth): the total number of RBs in the cell (each RB has 12 REs).

Calculation example Assuming that the maximum output power of the BTS system configuration is 40dBm (10W per channel), the results for different subcarrier intervals are as follows.
 

1. at subcarrier interval 15KHz 270RBs (cell bandwidth 50MHz):

• Reference signal power = 40-10 x log10(270x12) = 40-35.10
• Reference signal power = 4.9dBm

2. at subcarrier spacing of 30 KHz 273 RBs (cell bandwidth 100MHz):

• Reference signal power = 40-10 x log10(273 x12) = 40 - 35.15
• Reference signal power = 4.85 dBm

3. At subcarrier spacing of 60KHz 130RBs (cell bandwidth 100MHz)

• Reference signal power = 40-10 x log10(130x12) = 40 - 31.93
• Reference signal power = 8.07dBm

II.the total transmit power of 5G (NR) base station The calculation needs to take into account the maximum transmit power and the number of Tx antennas, which can be calculated by the following formula:

Antennas and cells with the same maximum power are 40 dBm, which can be calculated for different antenna configurations total Tx (transmit) power, which:8, 16, 64 and 128 antenna system when respectively as follows:

• 8Tx antenna total transmit power = 40 + 10xlog10(8) = 40 + 9.03 = 49.03 dBm
• Total transmit power of 16Tx antenna = 40+10xlog10(16) = 40+12.04 = 52.04 dBm
• 64Tx antenna total transmit power = 40+10 x log10(64) = 40+18.06 = 58.06 dBm
• 128Tx antenna total transmit power = 40+10x log10(128) = 40+21.07=61.07dBm

----- Total transmit power is the top-of-air power, including the antenna gain (directional gain in dBi) used to calculate the equivalent omnidirectional radiated power (EIRP).