Indoor Positioning with GPS-compatible Signals

Two novel indoor positioning methods with GPS compatible signals, Doppler positioning (pose estimation) with a moving receiver antenna and carrier-phase difference (CPD) positioning with a proximate multi-channel pseudolite (PMC-PL), are proposed. The Doppler positioning method determines the receiver's position by using the Doppler shift produced by moving a receiver antenna under the use of an indoor GPS transmitter. This method is extended to achieve the positioning in real-time while the receiver platform is moving, and estimate receiver's orientation with two or more transmitters. On the other hand, the CPD positioning method with a PMC-PL determines the receiver's position by using the phase differences between carrier waves transmitted from proximately-located pseudolite antennas (at the intervals of 95 mm). The experimental results show that these two methods can achieve the positioning accuracy less than one meter.