Hardware implementation of the space-time radio interferometric positioning system

Space-time radio interferometric positioning system (STRIPS) is a indoor localization system with low complexity that is robust to multipath effects. Its general idea follows a radio interferometric positioning system (RIPS), where two transmitters transmit sinusoidal signals at slightly different frequencies to create a slowly-varying envelope at a receiver. The receiver employs a cost-efficient envelope detector to extract the low-frequency differential signal, of which its phase contains a range information. Unlike the original RIPS, however, the STRIPS operates in the millimeter-wave (MMW) band, where the signal interference and multipath are less prominent than a typical radio-frequency (RF) band. In this paper, we implement the STRIPS on hardware and experimentally validate its performance. The experimental results show that the prototype we have built successfully achieves a submeter accuracy on average.