Multiple-input multiple-output (MIMO) systems with antenna selection are practical ones that can intuitively alleviate the computational complexity at the receiver and achieve good reception performance. Channel correlation, not just carrier-to-noise ratio (CNR), has a great impact on the reception performance in MIMO channels. We propose a simple antenna selection algorithm that exploits the condition number of the channel matrix and a predetermined threshold CNR. This paper describes the hardware implementation of the proposed algorithm and its performance evaluation, which was conducted in an indoor measurement using received signals obtained in the actual mobile outdoor experiment. The results confirm that our proposed method provides good bit error rate performance by setting a threshold CNR properly.