In this paper, three different frequency reconfigurable multiple-input-multiple output (MIMO) antennas are characterized in terms of their channel capacity performance in an indoor environment. Two 2×2 and one 4×4 MIMO antenna configurations are investigated. A complete MIMO system is implemented using software defined radio (SDR) platform. The antenna under test can be used at either transmitter or receiver ends. The channel capacity of the system is evaluated by computing the channel coefficient matrix. The measurements are performed at 2.45 GHz for line of sight (LOS) and non-line of sight (NLOS) scenarios. A comparison of the antennas is performed with an ideal system scenario with totally uncorrelated channels as well as an array of standard monopoles which are half-wavelength apart. The effects of antenna element efficiencies, radiation patterns and spacings on the channel capacity are discussed.
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