Robust power allocation for cognitive radio system in underlay mode

Abstract

. In this paper, the power allocation problem in cognitive underlay system is studied given a number of samples of interference channel’s gain. System throughput of secondary users is aimed to be maximized while limiting the worst-case interference outage probability. With only a number of samples of interference channel’s gain, we define an uncertain region of possible probability density function (PDF) of interference channel’s gain and further derive the closed-form expression for the interference outage probability constraint. By replacing the formulated constraint on interference outage probability with closed-form one, we show the originally formulated problem is a convex optimization problem.