NLOS mitigation based on a Trellis search for wireless location

Wireless location using time of arrival (TOA) and time-difference-of-arrival (TDOA) measurements has received considerable attention over the last years to be the best selection for cell phone location. The major problem related with these types of measurements is the non-line-of-sight problem (NLOS) that happens when the direct path between the base stations (BSs) and the mobile is blocked. This paper presents a new technique to mitigate the NLOS effect in dynamic scenarios based on a Trellis search of the NLOS state. Numerical simulation shows that the proposed technique outperforms the previous contributions because it is able to detect and reject the NLOS measurements.