Downlink capacity evaluation for indoor DAS in LTE networks

Providing high-performance indoor coverage, especially with continuous growth in high data rate demands, is a considerable challenge. This constitutes a major problem given that statistics indicate that 80% of data is expected to be generated from within indoor environments. Therefore, in order to achieve the objectives of LTE cellular systems in terms of reliable broadband communications, careful research has been taken into providing solutions for indoor communications. One of these solutions is the distributed antenna system (DAS). In DAS, a network of antennas is used to provide coverage within a given floor of a certain building. Consequently, multiple antennas within a given floor are expected to provide a better chance for line-of-site situations, the matter which improves the overall signal quality. In this paper, downlink capacity evaluation for an indoor distributed antenna system is performed. The aim is to find the optimum number of antennas that should be deployed in a specific system to optimize the use of available resources. The main target is to find efficient approximation models and to validate their level of accuracy through comparing them to the actual simulation. Different indoor propagation models are used in this paper to verify the validity of the proposed approaches and they all take into account the environment of the studied indoor area.