In this paper, we address the problem of optimizing the spectral efficiency of cellular indoor wireless networks by adjusting the location and power of the base-stations. Focusing on the downlink, we derive general network access criteria for mobiles on the indoor floor for systems that employ omnidirectional antennas and adaptive antennas arrays at the base-stations, in order to show and explain the advantages of the use of spatial diversity. Multiple access capability measures that depend only on energy are defined for both schemes. They are then used as the cost function for the solution to the optimal base-station placement problem, for a single-frequency system. Both continuous and combinatorial approaches have been applied to the solution of the optimization problem, and near-optimal solutions have been obtained. We show that the use of adaptive arrays yields greater capacity when increased cell-area overlap is allowed. The optimization methods, channel prediction methods, and a graphic user interface are parts of an integrated software environment that we developed in support of our investigation and which is described.

We address the improvement in multiple access capability of an indoor wireless network that is achieved when equipment employing adaptive arrays is used. We specifically apply this improvement to the problem of optimal base-station placement. In the past we have considered indoor environments with conventional omnidirectional antennas. In this study we consider indoor wireless systems using adaptive arrays at the base-stations, and compare the results to those of the previous case in order to show and explain the advantages of the use of spatial diversity. The multiple access capability measures derived for the adaptive arrays scheme are used in the cost function for the solution of the optimal base-stations placement problem. We show that, in contrast to the omnidirectional case, where the minimisation of the cell-area overlap maximizes the capacity of the system, the use of an adaptive arrays scheme, achieves greater capacity when heavier cell-area overlap is allowed.