Phase detection based range estimation with a dual-band robust Chinese remainder theorem

Range estimation with multifrequency phases is a common practice in localization systems. The challenge of this method is the phase ambiguity. Some Chinese remainder theorem (CRT) based phase unwrapping algorithms have been proposed to solve the problem, where the wavelengths of the multifrequency signals need to be pair-wisely co-prime after they are divided by their greatest common divisor (gcd). This condition may limit the application in practice. In this paper, a novel way based on a dual-band robust CRT is presented to reconstruct the distance from dual-band wrapped phases, where the pair-wisely co-prime condition is not necessarily needed. As more wrapped phases are involved to reconstruct the distance, the method can significantly enlarge the reconstruction range compared to the single band solution.