Signal Processing Techniques to Enhance Anti-Jam Performance for Low SWAP-C M-Code-based GPS User Equipment

TECH FOCUS AREAS: General Warfighting Requirements (GWR) TECHNOLOGY AREAS: Electronics OBJECTIVE: This topic seeks to identify and research signal processing techniques and/or algorithms improving anti-jam (AJ) performance over current MGUE capability and can be implemented in low size, weight, power, and cost (SWAP-C) military GPS M-code User Equipment utilized in multi-service operational applications. DESCRIPTION: For nearly three decades, anti-jam (AJ) research and products for GPS User Equipment (UE) have largely been focused on high performance systems like adaptive antenna systems. The capabilities of these primarily hardware-based systems have steadily evolved to extend enhanced AJ performance to military applications with Size, Weight, and Power and Cost (SWaP-C) constraints. In addition, under the MGUE Increment 1 Resiliency and Software Assurance Modification (RSAM) effort, additional receiver-based AJ enhancement techniques were investigated and in part implemented in the MGUE Increment 1 products. Nonetheless, there are still additional challenges in addressing the ever-increasing GPS threats for those military applications and equipment with significant SWaP-C limitations such as handheld receivers, very small, unmanned aerial and ground vehicles, and diver underwater navigation systems where adaptive antenna systems may not be operationally suitable because of array size, high cost, and computational complexity. The objective of this SBIR is to develop and assess single antenna signal processing techniques and algorithms for SWaP constrained M-code capable receiver to enhance the AJ performance by at least 20 dB (30 dB objective) over the current AJ performance specified for the MGUE Increment 1 ground-based receiver in the presence of both narrowband and broadband jammers (e.g., CW, Pulsed CW, Swept CW, Matched Spectral, Gaussian noise). The tradeoffs between jammer suppression, implementation complexity, and SWaP impact should be assessed with respect to representative SWaP constrained military receiver applications and integrations. Evaluate the benefit of utilizing existing built-in sensors like an IMU that are typically integrated within a military diver navigation unit along with an M-code GPS receiver to further enhance jammer suppression. Offerors are encouraged to work with MGUE prime contractors and developers of low SWaP M-code- receiver based systems to help ensure applicability of their efforts and begin work towards technology transition. Offerors' proposals should clearly indicate what Government furnished property or information are required to conduct this effort. PHASE I: Selected efforts will conduct a comprehensive comparative assessment and trade-offs of pre-and/or post correlation signal processing AJ enhancement algorithms and techniques for implementation with low SWAP-C M-code single antenna receivers and applications such as military underwater navigation systems which utilize various embedded sensors which can aid AJ implementation. Conduct analysis and simulations to demonstrate the level of AJ enhancement over the baseline MGUE Increment 1 AJ performance. Assess implementation complexity of candidate techniques and conduct trade-offs with respect to impact on SWAP-C, AJ performance, and operational suitability. Deliverables will be reporting of trade studies and accompanying analysis. PHASE II: Companies selected for Phase II will design, implement, integrate, and test the most promising and effective low SWAP-C AJ signal processing/algorithmic techniques with a representative M-code based receiver prototype to demonstrate AJ implementation and performance applicable to evolving low SWaP M-code based receivers. Efforts will demonstrate measurable AJ performance with the prototype utilizing representative sensor inputs like those provided by an M-code receiver-based military underwater navigation system. Deliverables will include any software or hardware demonstrations used for analysis and reporting. PHASE III DUAL USE APPLICATIONS: In cooperative efforts with one or more M-code-based receiver manufacturers and military underwater navigation system developers, integrate the proposed signal processing/algorithmic techniques with their respective products. Demonstrate the AJ performance, SWaP compatibility, and operational effectiveness of the algorithmic/signal processing enhancements in one or more upgraded products utilizing laboratory and field tests in representative operational and EW environments. Evaluate transition opportunities for utilization in approved Government civilian applications. NOTES: The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the proposed tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the Announcement and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the Air Force SBIR/STTR Help Desk: usaf.team@afsbirsttr.us REFERENCES: 1. M. W. Rosen and M. S. Braasch, Low-cost GPS interference mitigation using single aperture cancellation techniques, in Proc. ION NTM 1998, Long Beach, CA, USA, 1998, pp. 47 58 ; 2. T. Kraus, F. Ribbehege, and B. Eissfeller, Use of the signal polarization for anti-jamming and anti-spoofing with a single antenna, in Proc. ION GNSS+ 2014, Tampa, FL, USA, 2014, pp. 3495 3501. ; 3. K. Park and J. Seo, Adaptive signal processing method using asingle-element dual-polarized antenna for GPS interference mitigation, in Proc. ION GNSS+ 2017, Portland, OR, USA, 2017, pp. 3888 3897 KEYWORDS: GPS M-code; anti-jam; signal processing