Product Overview

As the use of GPS becomes more widespread in both commercial and military navigation and guidance systems, the need to assure the accurate and continuous functionality of the GPS receiver has become more acute. Radix Technologies has applied advanced signal and communications intelligence techniques developed for the exploitation of direct-sequence spread spectrum signals (DSSS) to processing GPS frequency bands and the embedded waveforms. By leveraging its adaptive beamforming expertise, Radix Technologies has developed an all digital Anti-Jam receiver for GPS applications. The receiver employs Radix’s patented Code Gated Maximum Likelihood (CGML) technique to simultaneously steer antenna beams towards the GPS satellites and deep antenna nulls towards the interfering signals. CGML generates the maximum signal to interference plus noise ratio (SINR) possible allowing GPS signal reception even in heavily jammed environments. CGML provides these benefits without requiring an Inertial Navigation System (INS) input to steer the beams as needed by other anti-jam receivers (this capability is called blind adaptation).

The BEAMSTAR receiver can accept up to eight antenna inputs, forms separate beams for each GPS satellite in view and adapts them independently for the given jamming environment. The receiver forms a Position VelocityTime (PVT) solution and has also been adapted to support carrier phase operation for high accuracy differential positioning applications. The BEAMSTAR receiver processes both the Standard Positioning Service (C/A code) and Precise Positioning Service (P(Y) code) signals and is available in L1 or L1/L2 configurations. The BEAMSTAR receiver includes eight high dynamic range, parallel RF receiving paths and high speed analog to digital conversion. The resulting very high rate digitized RF environment is then processed in Field Programmable Gate Arrays (FPGA) that provide the digital equalization, correllation and doppler removal functions. Spatial beamforming, signal detection and demodulation, satellite management and PVT solution generation are then performed by parallel Power PC processors. The allocation of functions to processing elements is illustrated in the block diagram.

Features and Benefits

• Simultaneous Beamsteering and Nulling action
  ­ Maximizes signal to interference plus noise ratio for highest anti-jam performance
  ­ Effective against broadband and narrowband jamming
• Blind Adaptive Anti-Jam Technique
  ­ Does not require special antenna arrays or antenna calibration
  ­ Does not require an INS input
• All Digital Design
  ­ Digital equalization mitigates the effect of multiple RF path differences to provide deep nulls on jamming signals
  ­ Field Programmable Gate Arrays (FPGA’s) provide ease of feature upgrades and integration with ultratightly coupled navigation system architectures
  

BEAMSTAR GPS Anti-Jam Receiver Block Diagram

click for larger image

Contact Radix Technologies, Inc. Marketing at 1-650-988-4707 for details and adaptation to alternate configurations and mission scenarios.