Experimental performance evaluation of location distinction for MIMO links

A radio channel-based location distinction system monitors physical layer measurements of received signals to detect if a transmitter has changed position since its previous transmission. This paper explores the design space for MIMO-based location distinction systems. Using extensive channel measurements collected with two different MIMO testbeds, we make several observations about the tradeoffs inherent in MIMO location distinction, and the scaling of performance with respect to bandwidth, history size and insertion delay, and number of antenna elements. We show that MIMO location distinction is very reliable. For example, a 2×2 MIMO channel with a bandwidth of 80 MHz allows a 64-fold reduction in miss rate over the single-input single-output (SISO) channel for a fixed false alarm rate, achieving false alarm rates as low as 4 × 10^-4 for a 2.4 × 10^-4 probability of missed detection.