Performance study of an adaptive dual antenna handset for indoor communications

The focus of the paper is the design and evaluation of adaptive diversity for mobile handsets. Usually, diversity principles are optimised for base stations. However, for mobile new concepts must be developed to the size and power consumption constraints. A new modelling approach is introduced, which combines indoor radio channel simulations with circuit design parameters. This enables the inclusion of key system parameters, such as the speed of the user, the scanning speed of the antenna beams and the number of phase shifts. The radio channel simulations are based on a high-order finite-difference algorithm using the Berenger (1994) absorbing boundary condition to truncate the computational domain. The algorithm is found to be efficient and accurate enough to simulate very large structures. The analysis has resulted in an optimal design of an adaptive dual antenna handset, which combines received signals (fixed beam) while scanning the environment at the same time (scan beams). A prototype is evaluated with the numerical modelling tools and a measurement set-up. The performance is close to that of a perfect equal gain combiner