Indoor-GPS: Ist der Satellitenempfang in Gebäuden möglich?

Summary GPS signals penetrating a wall will be attenuated by factors up to 100 and more dependent on the material of the wall. In an outdoor environment a common receiver is capable to acquire the signal within some seconds. In contrast to this the same receiver needs a much longer period to achieve a suitable signalto-noise ratio in indoor environments. However, for the user this is not acceptable. A faster acquisition in indoor environments can be realised pursuing two approaches: assistance by a cell phone network and massive parallel correlation. The latter one can be realised either in the time domain (massive parallel) or in the frequency domain (FFT). By means of assistance respectively massive parallel correlation, on the one hand the search space can be reduced and on the other hand the computing power of the receiver during the correlation process can be increased by a factor of 500 or more. This paper focusing on indoor location using GPS presents the physical framework, technical realisations and a brief receiver test.