Measurements and evaluations of multi-element antennas based on limited channel samples in a reverberation chamber

In this paper, evaluations of diversity gains and capacities of multi-element antenna based on limited channel samples in a reverberation chamber (RC) are studied. It is shown that, for a large antenna array, the classical sample estimation based on finite channel samples tends to underestimate its diversity gain and capacity. An improved (yet slightly more complicated) eigenvalue estimation method is applied in both diversity gain and capacity calculations, which effectively alleviates the estimation bias. The findings of the present paper are applicable for measurements where the maximum independent channel samples per antenna element are limited. Apart from simulations, we also evaluate the performances of the classical and improved eigenvalue estimators based on measurements in a RC. Based on the results of this paper, the performance of the RC measurement (with limited samples) for multi-element antennas can be readily enhanced.