B.4 BTS power control

05.083GPPRadio subsystem link controlTS

The same algorithm as above can be used for downlink power control. The formula for quality based control in the MS

Pn+1 = Pref +  (Ln + IBTS,n)

can be written for the BTS as:

Pdn+1 = Pref +  (Ln + CH,n)

where Pd is the BTS output power (equal to PBTS – Pb). CH is the received interference level at the MS.

Substituting the path loss and dropping the iteration index gives: Pd = Pref +  (PBTS – C + CH)

The received signal C and interference CH is measured in the MS and transferred to the BTS, which can calculate the output power.