Anti-Jam GPS Receiver Architecture Using Available Antennas

With increasing reliance on GPS, precise navigation in the presence of jamming is essential. Controlled Reception Pattern Antennas (CRPA’s) provide adaptive beamforming to project nulls towards the jammers. CRPA’s typically consist of multiple elements in a certain manifold with phase between elements adjusted for desired beam patterns. Many vehicles are not equipped with CRPA, but have multiple antennas for robust navigation (under maneuvering) and attitude determination. These antennas could be used to provide anti-jam performance against a single or multiple (depending on number and orientation of antennas) jammers. This proposal describes a plan to develop such a system. Anti-jam techniques involving phase (DFT) and time based approaches (TDOA) coupled with constrained beamforming/beam-steering will be simulated to determine the direction of arrival and null the jammer(s) under different conditions. In addition, a GPS/MEMS-INS will be integrated into the system simulation to provide enhance jammer resistance. In Phase I an anti-jam receiver will be developed and simulated in software using a simulation environment (IMPULSE™). Performance metrics obtained will be used to compare anti-jam margins in different jamming conditions versus a CRPA array. This system simulation will provide a framework to develop a working prototype that will be field tested during Phase II.