In the last years indoor positioning is getting more and more important for industrial and commercial usage. Progressive approaches are developed to use leaky coaxial cables (LCX) not only for radio coverage but also for indoor navigation, too. Here latest results of the WIPoS project are shown, which focus on indoor positioning based on LCX measurements applying RF fingerprinting. With RF fingerprinting the received signal power levels are measured at equidistant positions and are stored in a radio map. An increase of the localization accuracy is achievable by reducing the power level fluctuations measured at the LCX cable ends, which were used for RF fingerprinting. Several averaging algorithms like averaging by time, place, antenna orientation, RF channel bandwidth and combinations of them had been applied for smoothing the power level fluctuations. But the achievable improvement on the indoor positioning accuracy was still insufficient for practical applications. Therefore the different effects leading to receive power fluctuations had been extracted and are explained in this paper. Based on these investigations the results of the first LCX prototype are presented.