On the Geo-Location Bounds for Round-Trip Time-of-Arrival and All Non-Line-of-Sight Channels

Development of future geo-location systems requires a fundamental understanding of the importance of various system parameters, such as the number of sensors, the SNR, bandwidth, and channel conditions. We consider the bounds on time-based geo-location accuracy when all sensors experience non-line-of-sight (NLOS) conditions. While location accuracy generally improves with additional bandwidth, we find that NLOS effects place a limit on these gains. Our evaluation focuses on indoor geo-location where Rayleigh fading is present, different SNR conditions occur on each link, and the sensors may not fully encircle the user. We introduce a new bound for round-trip time-of arrival (RT-TOA) systems. We find that TOA outperforms TDOA and RT- TOA, but the relative ordering of the later two depends on the sensor geometry.