Pulsed Interference Mitigation for a NavIC Reference Receiver

Abstract

Navigation with Indian Constellation (NavIC), also known as Indian Regional Navigation Satellite System (IRNSS), is the Indian regional satellite navigation system. NavIC relies on a vast network of one-way ranging reference stations for its precise orbit determination and time synchronisation (OD&TS) functions. These reference stations are equipped with reference receivers which act as measurement engines and provide the raw code and carrier phase measurements to the OD&TS process. NavIC provides navigation services in two Radio Frequency (RF) bands, namely L5 and S. L5 band, centred at 1176.45 MHz is susceptible to pulsed interference from Distance Measuring Equipment used for civil aviation. ISTRAC is currently undertaking the development of an indigenous tri band reference receiver for the one way ranging stations of the NavIC ground segment. An asynchronous Pulse Blanker has been implemented for the in-house NavIC Tri-band Reference receiver for the detection and mitigation of the pulsed interference in L5. Furthermore, implementation of digital pulse blanking has been designed to be independent of the RF band and thus can provide benefits to NavIC receivers operating at frequencies other than L5, i.e. S with its known dense interference environment.