In this paper, a distributed antenna system (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. The capacity of the system is analyzed considering direct propagation inside the building and reflection from a nearby building. 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 position of the RAUs on the performance is discussed.