Capacity of distributed antenna systems in multi-floor buildings

The requirement of high data rate in wireless communication has led to the need to shorten the distance between the base station and the mobile user. Distributed antenna system (DAS) is an effective solution to this problem. In this paper, DAS is investigated for indoor high data rate wireless transmission in high buildings. In the proposed indoor DAS, radio transmission/reception within several neighbouring floors is controlled by one central unit (CU) by exploiting the whole system bandwidth. However, the frequency channels can be reused among the CUs which results in co-channel interference. System channel capacity is analyzed based on a proposed mathematical channel model. Moreover, the impact of several system parameters, such as the position of the user on the floor, the number of remote antenna units (RAUs), the shape of the floor and the deployment of the RAUs on the performance is discussed.