Methods of Improving the Jamming Resistance of GNSS Receiver

Abstract Jamming of GNSS signals can be both a consequence of accidental activities and an intentional act. This issue is lately discussed as an essential threat for the use of satellite navigation systems. This is especially dangerous in the face of common usage of GPS - like systems in everyday life and the great belief of everyday users in the truth of devices indications. In spite of the legal prohibition of using them, jammers are commonly accessible, especially in the Internet. Until recently even specialists have shared the conviction that the broadband GPS signal is not a subject of disturbances in contrast to older wireless communication techniques because its power level is below natural level of noises and in addition it is randomly coded. But nowadays jammers are very often successfully applied, which is confirmed in many reports. The average user has not the suitable knowledge about the specificity of the jamming and has no technical possibilities of the detection of jammer signals. Receivers, which can indicate the presence of perturbative signals, became accessible a few months ago only. Presently accessible jamming monitors can also determine the direction of interferer signal transmission. There are also specially designed receivers with anti-jamming mechanism, which are, however, not commonly accessible. The possible way of countermeasure the jamming in the GNSS receiver are discussed in this paper.