Cooperative Indoor Localization Using 24-GHz CMOS Radar Transceivers

This paper presents the first truly wireless 24-GHz round-trip time-of-flight local positioning frontend with an integrated CMOS transceiver. The transceiver in 130-nm CMOS technology features a novel receiver/transceiver switching concept, which reduces RF losses between the receiver/transmitter and antenna and drastically improves the transmit/receive isolation. The low-power RF transceiver chip was integrated with a digital signal-processing unit and mounted on a circuit board to form a system-level demonstrator of a secondary radar node incorporating synchronization and a distributed localization algorithm. The performance of the self-organizing localization network is evaluated in an indoor setup using comparisons with reference trajectories. Experimental results show a distance precision between the active nodes close to the theoretical optimum that can be achieved with the used signal parameters, as well as an absolute localization error in the centimeter range.