Design Criteria for Distributed Antenna Systems

In this paper, we discuss three different design criteria for a distributed antenna system (DAS). They are maximizing throughput under the constraint of the overall transmit power, minimizing the overall transmit power while guaranteeing the minimum spectral efficiency (SE) requirements, and maximizing energy efficiency (EE) under the constraints of minimum SE requirements and overall transmit power. We use sub-gradient iteration approach to solve the first two optimization problems and exploit fractional programming method to deal with the third one. Based on these design criteria, three power allocation algorithms are developed for the downlink multi-user DAS. Depending on application enviroments, we can use the first and second criteria to achieve the highest throughput and to save the most energy, respectively, while we can balance throughput and energy consumption using the third criterion.