System and methods for configurable EIRP restriction

1 . A method of operating a distributed unit, DU, of a radio network node in a wireless communication system, comprising:

obtaining a value of an antenna subarray gain, G subarrayAndElement , for a radio unit, RU, connected to the DU;

estimating a transmission gain associated with a first downlink channel of the RU based on the antenna subarray gain;

calculating an effective isotropically radiated power, EIRP, level for the first downlink channel based on the estimated transmission gain of the first downlink channel; and

adaptively limiting EIRP of downlink signals transmitted by the RU on the first downlink channel based on the estimated transmission gain.

2 . The method of claim 1 , further comprising obtaining a port-to-antenna mapping gain, G p2a , of the RU, wherein the estimated transmission gain of the first downlink channel is estimated based on the port-to-antenna mapping gain, G p2a , of the RU.

3 . The method of claim 1 , wherein the estimated transmission gain of the first downlink channel is based on one or more of a precoding gain, G precoding , a tuning gain, G tuning , and a boost gain, G boost .

4 . The method of claim 1 , further comprising receiving the antenna subarray gain from the RU.

5 . The method of claim 1 , further comprising receiving the antenna subarray gain from a local database in the DU.

6 . The method of claim 1 , further comprising receiving the antenna subarray gain in a network configuration.

7 . The method of claim 2 , further comprising obtaining the port-to-antenna mapping gain, G p2a , of the RU from a local database in the DU.

8 . The method of claim 1 , wherein adaptively limiting the EIRP of downlink signals transmitted by the RU on the first downlink channel comprises obtaining a power backoff value based on the estimated transmission gain.

9 . The method of claim 8 , further comprising:

generating a scaling factor based on the power backoff value; and

transmitting the scaling factor to the RU.

10 . The method of claim 8 , further comprising:

generating a scaling factor based on the power backoff value;

applying the scaling factor to modulated data symbols; and

transmitting the modulated data symbols to the RU for transmission.

11 . The method of claim 1 , wherein the estimated transmission gain of the first downlink channel is estimated based on one or more of a precoding gain, G precoding , a port-to-antenna mapping gain, G p2a , a antenna subarray gain, G subarrayAndElement , a tuning gain, G tuning , and a boost gain, G boost .

12 . The method of claim 1 , wherein the first downlink channel comprises a physical downlink shared channel associated with a wireless device, and wherein the estimated transmission gain of the first downlink channel, G pdsch , is calculated as:

G

pdsch

=

G

precoding

+

G

p

⁢

2

⁢

a

+

G

subarrayAndElement

+

G

tuning

+

G

layersplit

+

G

boost

where G layersplit represents a gain associated with a number of MIMO layers transmitted on the first downlink channel.

13 . The method of claim 11 , wherein the EIRP level for the first downlink channel is calculated as a sum of the estimated transmission gain and the transmission power of the first downlink channel.

14 . The method of claim 12 , wherein the EIRP level for the first downlink channel is calculated as:

EIRP

pdsch

=

G

pdsch

+

TXPower

where TXPower represents the transmission power on the first downlink channel.

15 . The method of claim 14 , further comprising calculating an EIRP backoff as:

pdschEirpBackoff

=

max

⁡

(

0

,

EIRP

pdsch

-

maxEirpTh

)

where maxEirpTh is a maximum EIRP threshold.