Optimal Power Allocation for DAS-OFDM under Joint Total and Individual Power Constraints

Abstract

We derive new optimal power allocation solutions for a distributed antenna system with orthogonal frequency division multiplexing (DAS-OFDM), in which K remote radio heads (RRHs) allocate power over N subchannels with both in-dividual RRH and total system power constraints. The individual RRH constraints may be necessary due to hardware limitations, while the total power constraint allows the system to limit the overall energy consumption for cost and/or green environmental factors. In order to obtain some insight on the optimal power allocation, we focus on a simple two-RRH case in this paper. The resulting optimal power allocation solution has an interesting sparse feature: Among N subchan..