SBIR-STTR Award

Ensco will determine the feasibility of incorporating an adaptive antenna array in a GPS receiver for use on air-to-surface weapons. The array will be used to null interference such as that produced by intentional jammers. To date, little, if any, research has investigated the feasibility of using adaptive antenna arrays in GPS receivers. We will determine the cost effectiveness of system designs which achieve fast interference nulling and provide fast, reliable GPS information. We will develop and run simulations to analyze and compare antenna arrays and adaptive beamforming algorithms suitable for a tactical environment. We will also determine what changes must be made to an off-the-shelf GPS receiver to incorporate the adaptive array.

Keywords:
Beamforming Adaptive Antenna Array Anti-Jam Spread-Spectrum Gps

ENSCO's Phase II technical objectives are to: 1) build a printed circuit board (PCB) prototype of the adaptive antenna array that was designed and simulated in the Phase I study, and interface it to a GPS receiver, and 2) demonstrate and evaluate the anti-jam performance of the system in field tests. The array is expected to null multiple broadband jammers with jammer to signal power ratios (JSR) of up to 100 dB and nulling will typically be achieved within 20 microseconds after the jammers are activated. No modification to the GPS receiver will be required, but ephemeris satellite position data, provided by the receiver, will be processed in order to determine satellite orientation relative to the antenna array. The system uses this information to aid the selection of an optimum antenna gain pattern; providing gain in the directions of the GPS satellites and nulls in the directions of the jammers.

Keywords:
Beamforming Adaptive Antenna Array Anti-Jam Spread-Spectrum Gps