Measured Capacity Evaluation of Indoor Office MIMO Systems using Receive Antenna Selection

A multiple-input multiple-output (MIMO) system that uses antenna selection schemes at receiver enables us to reduce radio frequency (RF) chains and provide a gain enhancement. That means low-cost and better performance can be obtained compared to a conventional MIMO system. In this paper, we present measured capacity and bit error rate (BER) performance evaluation of an indoor office MIMO system using a receive antenna selection at 5 GHz band. It is found that an ideal selection improves approximately 4 dB in a 2 times 2 MIMO system from a result of a cumulative distribution function versus the gain enhancement. Furthermore, the ideal selection for maximizing the measured capacity and minimizing the BER performance is not always the same due to a noise enhancement which depends on a condition number or a correlation of MIMO channel matrix. Note that an antenna selecting criterion between a single-input multiple-output (SIMO) and MIMO systems is different. In the former case, the criterion is based on an SNR or a signal-to-interference-plus-noise-ratio (SINR) even if the forward error correction (FEC) techniques are used, while the criterion for the latter is not always the SNR nor the SINR