Abstract: A method for locating the source of a passive intermodulation (PIM) fault in a radio frequency (RF) system, the method comprising: a) generating a PIM fault fingerprint database by: modelling an RF network; defining a plurality of PIM fault patterns for the modelled RF network by defining PIM faults at one or more sources; simulating a received RF signal for each respective PIM fault pattern; generating the PIM fault fingerprint database in dependence on the simulated received RF signals for each defined PIM fault pattern; b) measuring an RF signal for a real network having a PIM fault and abstracting the measured RF signal to define a given signal; c) searching and matching the given signal using the fingerprint database to determine the PIM fault pattern; and d) locating the source of the PIM fault, or giving a further measuring guideline in dependence on the determined PIM fault pattern.

Abstract: A method for determining the position of a mobile or asset in an indoor location in a radio frequency system, the method comprising: a) generating a Wi-Fi multi-band fingerprint database using at least one multi-band Wi-Fi access point configured to simultaneously transmit multiple frequency band wireless signals; b) selecting a most probable frequency band having the highest probability function for a target location of the mobile or asset given one or more measured signals; c) selecting one or more fingerprints from the Wi-Fi multi-band fingerprint database in dependence on the selected frequency band and selecting a measured signal that is needed to determine the location in dependence on the said most probable frequency band for each Wi-Fi access point; and d) comparing the selected measured signal and the selected one or more fingerprints to determine the location of the measured signal in dependence on a location estimation algorithm.

Abstract: A method for rapidly creating an indoor wireless signal fingerprint database, comprising the following steps: constructing an indoor and outdoor combined three-dimensional scene model of a target building, predicting wireless signal field intensity information of 3D space using a ray-tracing algorithm, selecting a small quantity of testing points to perform manual field measurements and recording the wireless signal intensity information, correcting/calibrating 3D ray-tracing propagation model parameters based on the difference between the actually measured wireless signal intensity information and the theoretical wireless signal intensity information calculated through the 3D ray-tracing propagation model.

Abstract: A method for rapidly creating an indoor wireless signal fingerprint database, comprising the following steps: constructing an indoor and outdoor combined three-dimensional scene model of a target building, predicting wireless signal field intensity information of 3D space using a ray-tracing algorithm, selecting a small quantity of testing points to perform manual field measurements and recording the wireless signal intensity information, correcting/calibrating 3D ray-tracing propagation model parameters based on the difference between the actually measured wireless signal intensity information and the theoretical wireless signal intensity information calculated through the 3D ray-tracing propagation model.