You are here

USMC Ground Radio LPI/LPD Interference Mitigation Active Communication Antenna

Description:

TECHNOLOGY AREA(S): Info Systems 

OBJECTIVE: The Multiband Ground Radio program needs to reduce the radio frequency (RF) signature of the Marine Air-Ground Task Force (MAGTF). The September 2016 Marine Corps Operating Concept (Reference 1) identifies a critical task to “Operate with Resilience in a Contested-Network Environment.” The development of Low probability of Detection (LPD) and Low Probability of Intercept (LPI) antenna that simultaneously provide interference mitigation is the solution to the critical subtask of “Role of Signature in Offense and Defense” and allows us to operate with resilience in the contested-network environment as per the Marine Corps Operating Concept (MOC). 

DESCRIPTION: Marine Corps Systems Command (MARCORSYSCOM) utilizes multiple communications systems, in particular dismounted ground radio systems, to interconnect with the Networking on the Move (NOTM) program. In an operational environment, the tactical communications systems encounter interference with reduced available spectrum and increased demand in data. Dismounted Marines need to be able to operate without being detected by the enemy and/or emitting RF. Increasing use of the electromagnetic spectrum reduces the available channels to communicate and increases interference between co-adjacent channels in combat. The development of technology solutions for increasing spectrum availability require systems to use spatial diversity, interference mitigation, and manage output power with directional gain so that systems may be closer, be non-detectable outside the main beam, and share the same spectrum. A communications system that simultaneously provides a small form-factor, on-the-move communications, and LPI/LPD capability with interference mitigation is a technological challenge. MARCORSYSCOM is looking for a solution that will provide an interference mitigation active antenna that will connect to the AN/PRC-117G via the J3 or J6 ports. These ports provide Ethernet, USB, or RS232 capability and one of these standards will be used for the antenna interface. Reference 2 provides a link to the AN/PRC-117G manufacture and specification sheet and Reference 3 provides a sample supplier of weatherproof cables to attach to the J3 or J6 ports. The connector used for these ports is standardized among the family of tactical radios and therefore a solution for the AN/PRC-117G will also work with other tactical radios just needing a different cable or connector. A technical paper that provides a good description of the problem to obtain LPI/LPD transmissions is titled “Hiding Information in Noise: Fundamental Limits of Covert Wireless Communication” and is provided in Reference 4. The requirements for this communications systems are as follows: The system must support a minimum throughput of 2 Megabits per second (Mbps), transmission range of up to 70nm, and be able to transmit in at least one band from L Band (0.5GHz) to X Band (12GHz) (Threshold) or transmit in multiple bands (Objective) but include L Band as one of the bands, and be a light-weight man-packable system weighing no more than 5lbs. (Threshold) - (not including the battery). The active antenna should sense all frequencies between 0.5GHz and 12GHz (Threshold) and be able to output the frequency power spectrum (Threshold). The active antenna system will operate on battery power for 8 hours of continuous use (Threshold). The system will be able to be charged or run on 110V AC, 12V DC power sources and be able to be powered by the AN/PRC-117G (Threshold). The system will be undetectable outside of the main beam (3dB point is the main beam) and will have a non-detectable RF signal that is below the ambient RF noise floor from 100MHz to 50GHz 99% of the time (Threshold) and should be undetectable by a non-cooperative system within the main beam (Objective). A non-cooperative system is one that does not have knowledge (e.g., enemy or neutral system) of the transmission waveform. The system must be able to null adjacent frequency interference from at least one source (Threshold) and up to four sources (Objective). The system shall be usable in all tactical environments and preference is given to a system concept with no moving parts (reduced maintenance). The active antenna shall be able to be reconfigurable or reprogrammable to allow for future changes or upgrades. Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. Owned and Operated with no Foreign Influence as defined by DOD 5220.22-M, National Industrial Security Program Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Security Service (DSS). The selected contractor and/or subcontractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances, in order to perform on advanced phases of this contract as set forth by DSS and the Marine Corps in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material IAW DoD 5220.22-M during the advance phases of this contract. 

PHASE I: The company will develop concepts for an interference mitigation active antenna that meets the requirements described above. The company will demonstrate the feasibility of the concepts in meeting Marine Corps needs and establish the concepts that can be developed into a useful product for the Marine Corps. Feasibility will be established by material testing and analytical modeling, as appropriate. The small business will provide a Phase II development plan with performance goals and key technical milestones, and that will address technical risk reduction. This Phase II plan will include specification for a prototype. 

PHASE II: Based on the results of Phase I and the Phase II development plan, build an operational prototype for evaluation. The prototype will be evaluated to determine its capability in meeting the performance goals defined in the Phase II development plan and the Marine Corps requirements for the interference mitigation active antenna. System performance will be demonstrated through prototype evaluation and modeling or analytical methods that demonstrate the communications throughput and LPI/LPD detection requirements. Evaluation results will be used to refine the prototype into an initial design that will meet Marine Corps requirements. The company will prepare a Phase III development plan to transition the technology for Marine Corps use. It is probable that the work under this effort will be classified under Phase II (see Description section for details). 

PHASE III: Support the Marine Corps in transitioning the technology for Marine Corps use. The company will develop interference mitigation active antenna for evaluation to determine its effectiveness in an operationally relevant environment. Support the Marine Corps for test and validation to certify and qualify the system for Marine Corps use. Directional antennas with interference mitigation have potential use in any application in which close-in interference and long-range gain is desired. A potential commercial application is in digital signal broadcasts to provide a directive antenna and reduce interference in directions not in the main 3dB beam. Products such as these are already available on the commercial market but not with the active ability to cancel interference. 

REFERENCES: 

1: "Marine Corps Operating Concept." September 2016, http://www.mccdc.marines.mil/MOC/

2:  AN/PRC-117G Wideband Tactical Radio, July 2017, https://www.harris.com/solution/harris-falcon-iii-anprc-117gv1c-multiband-networking-manpack-radio

3:  AN/PRC-117G Cables and Information, July 2017, http://www.tacticaleng.com/radio-cables/an-prc-117g/

4:  Bash, Boulat A.

5:  Goeckel, Dennis

6:  Guha, Saikat

7:  Towsley, Don, "Hiding Information in Noise: Fundamental Limits of Covert Wireless Communication", 30 May 2015, https://arxiv.org/abs/1506.00066

KEYWORDS: Interference Mitigation; Low Probability Of Intercept; LPI; Low Probability Of Detection; LPD; Active Antenna; Communications; Tactical Radios; Active Interference Cancellation 

CONTACT(S): 

Bradford Crane 

(703) 432-2847 

bradford.crane@usmc.mil 

Ralph Jean-Bart 

(703) 432-9891 

US Flag An Official Website of the United States Government