Analyzing Wireless Indoor Communications by Blockage Models

The performance of wireless cellular networks in indoor scenarios is in large parts characterized by the blockage objects such as walls. These objects can be included in the system model in several ways. We present in this paper different wall generation methods, ranging from approaches from random shape theory (in 1-D and 2-D) to semideterministic and heuristic approaches. To attain comparable results, we ensure that the average wall volume for each method is constant. This results in the same average attenuation for distinct paths, which is shown analytically as well as by simulations. We apply a regular transmitter grid, show the influence of the relative orientation between walls and transmitter-receiver path and also elaborate on the influence of interferers in different tiers around the desired transmitter. Based on the average attenuation, we introduce the necessary approximations to yield tractable expressions for average performance in terms of Signal-to-Interference Ratio (SIR). These approximations are necessary to reflect the fluctuations among the instantaneous SIR values for the individual realizations of the blockage scenario and also due to the spatial correlation of blockages influencing several transmitter-signals simultaneously. Our results show a good accordance among the analytical and simulation results. Furthermore, we find the random wall generation method in two dimensions as the worst case scenario and the regular wall generation method as the best case scenario under the constraint of constant average wall volume.