WCDMA Common Pilot Power Control with Cost Function Minimization

This paper validates the feasibility of automating the setting of common pilot power in a WCDMA radio network. The pilot automation improves operability of the network and it is implemented with control software aiming for load balancing while also assuring pilot coverage. The pilot power of a cell is periodically updated with a gradient descent method that minimizes a cost function. The cost function describes differences in load between the cell and neighboring cells and pilot coverage that terminals of the cell measure. The approach was validated using a dynamic WCDMA system simulator with a deployment of macro and micro cells on a city region whose measured propagation characteristics were incorporated into the model. The results showed that the proposed control method slightly improved the air interface performance measured as a function of packet throughput.