A theoretical performance analysis of the modernized GPS signals

The frequency and signal design of the American global positioning system (GPS) is currently in a modernization period. The baseline configuration of GPS only consists of two signals on two carrier frequencies (C/A and P(Y) code). At present the existing satellites (IIA, IIR) are replaced by new modernized satellites (IIR-M, IIF) which are capable of transmitting additional signals. The modernization of GPS includes the extension of the frequency plan by a third frequency band (L5). We will evaluate the theoretical potential performance of the baseline signals and the new modernized signals of GPS in terms of positioning accuracy. This includes a discussion of the main error sources and the signal characteristics (signal modulation, carrier frequency and receiver bandwidth). Based on the contributions of the individual error sources we will give estimations of the typical performance of GPS for single-frequency and double-frequency receivers.