Location Distinction in a MIMO Channel

Location distinction is defined as determining when a device has changed its position. Previous work [4], [8] has shown that a wireless network can be exploited to successfully perform location distinction by measuring the characteristics of the SISO radio channel between the wireless device and one or more receivers. We propose methods and metrics for MIMO-based location distinction. Using a large set of MIMO channel measurements, we show that location distinction can be successfully applied to a MIMO channel. The accuracy of MIMObased location distinction improves as the number of antennas in the MIMO array is increased. In particular, a 2x2 MIMO channel demonstrates a significant performance improvement over the SISO channel, achieving, for example, a 0.0004 probability of false alarm for a 0.0001 probability of missed detection. The very high reliability of location distinction in MIMO enables location distinction systems to detect the change in position of a transmitter even when using only one receiver.