Abstract: A closed loop, real-time, cognitive Electronic Warfare (EW) system without a threat database includes an EW receiver for receiving radar threat signals; a Signal Analysis and Characterization module; a Pulse to Emitter Association sub-module; a Function De-interleaving Classifier sub-module; a Threat Behavior Model sub-module; a Countermeasures Synthesis module; a Capability, Severity, and Intent sub-module; a Countermeasure Selection sub-module; a Countermeasure Optimization sub-module; a Countermeasures Effectiveness Assessment module; a Resource Management module; and an EW transmitter.

Abstract: A distributed transmit platform deception network array system includes a plurality of platforms; each platform comprising at least one transmitter; wherein the platforms are in a geographically distributed configuration with respect to each other and at least one victim receiver; a propagating wavefront is generated by the transmitters of the plurality of platforms toward the at least one victim receiver according to deception target characteristics for each identified victim receiver; whereby the propagating wavefront is controlled, and a false location is determined by the victim receiver, Whereby detection of a deception at alternate receiver locations is minimized by selection of characteristics of the transmitted waveform.

Abstract: The discriminability of an RF fingerprint is increased by “abstracting,” “enhancing,” and “reconstructing” a digital signal before it is transmitted, where the abstraction is a reversible nonlinear compression, the enhancement is a modification of the abstracted data, and the reconstruction is a mapping-back of the abstraction. During a training phase, for each individual RF transmitter, RF fingerprints are analyzed and candidate enhancements are modified until a successful enhancement is identified that provides satisfactory discriminability improvement with minimal signal degradation. The successful enhancement is implemented in the RF transmitter, and the RF fingerprint is communicated to receivers for subsequent detection and verification. Reinforcement learning can direct modifications to the candidate enhancements. The abstraction can implement a deep generative model such as an auto-encoder.

Abstract: A closed loop, real-time, cognitive Electronic Warfare (EW) system without a threat database includes an EW receiver for receiving radar threat signals; a Signal Analysis and Characterization module; a Pulse to Emitter Association sub-module; a Function De-interleaving Classifier sub-module; a Threat Behavior Model sub-module; a Countermeasures Synthesis module; a Capability, Severity, and Intent sub-module; a Countermeasure Selection sub-module; a Countermeasure Optimization sub-module; a Countermeasures Effectiveness Assessment module; a Resource Management module; and an EW transmitter.

Abstract: The discriminability of an RF fingerprint is increased by “abstracting,” “enhancing,” and “reconstructing” a digital signal before it is transmitted, where the abstraction is a reversible nonlinear compression, the enhancement is a modification of the abstracted data, and the reconstruction is a mapping-back of the abstraction. During a training phase, for each individual RF transmitter, RF fingerprints are analyzed and candidate enhancements are modified until a successful enhancement is identified that provides satisfactory discriminability improvement with minimal signal degradation. The successful enhancement is implemented in the RF transmitter, and the RF fingerprint is communicated to receivers for subsequent detection and verification. Reinforcement learning can direct modifications to the candidate enhancements. The abstraction can implement a deep generative model such as an auto-encoder.

Abstract: An unattended apparatus and method for isolating and relaying secure communications under adverse circumstances without awareness of encryption keys uses known and/or inferred characteristics of received transmissions to identify, isolate, and retransmit only friendly communications without decryption or re-encryption, and in embodiments also without awareness of applicable TRANSEC algorithms and keys. A channelizer digitizes energy received within a bandwidth of interest, which is then analyzed to detect chip timing, identify and demodulate pulses, and assemble secure messages for retransmission. In embodiments, the retransmissions use the original frequencies and TRANSEC parameters, and/or otherwise adhere to applicable TRANSEC and MSEC constraints so that the relayed messages are accepted by intended recipients. Embodiments provide interoperability with existing secure communications such as Link 16 and CDL.

Abstract: A method of digital signal processing includes modeling a digitally-modulated radio frequency (RF) communication stream using a set of incoming samples of the stream collected from a single antenna. The stream includes a first signal, the first signal including a sequence of first digital symbols having a previous symbol and a current symbol. Each first digital symbol is chosen from a plurality of first possible values. The first signal is modulated by a first known RF communication protocol having unknown time-varying parameters, the parameters having estimated previous values from modeling the previous symbol using a previous interval of the samples corresponding to the previous symbol. The method further includes collecting a current interval of the samples, predicting current values of the parameters, deciding a value of the current symbol using maximum likelihood estimation, and estimating the current values of the parameters using maximum likelihood estimation.

Abstract: The system and method of utilizing frequency waterfilling and implicit coordination to mitigate signal jamming in Link 16 systems. The system and method of utilizing frequency waterfilling for Link 16 includes updates to both software and firmware. The frequency waterfilling approach for Link 16 modifies the process by which data bits are allocated to hops based on an assessment of hops affected by jamming, thus avoiding portions of the spectrum occupied by a jammer.

Abstract: The system and method of utilizing frequency waterfilling and implicit coordination to mitigate signal jamming in Link 16 systems. The system and method of utilizing frequency waterfilling for Link 16 includes updates to both software and firmware. The frequency waterfilling approach for Link 16 modifies the process by which data bits are allocated to hops based on an assessment of hops affected by jamming, thus avoiding portions of the spectrum occupied by a jammer.

Abstract: What is provided is a system for maintaining acceptable error rates in a MUD-enabled ad-hoc network. In this system the power spread associated with all of the nodes is maintained within the dynamic range of the system, for instance 30 dB. Also, the signal-to-noise ratio at an intended receiver is maintained above a predetermined minimum SNR, for instance above 5 dB. If the dynamic range rule is not met, then the power at the transmitting node is attenuated such that the dynamic range rule is met, checking to see that the minimum SNR rule is also met, or the transmission from this node is pulled. If there is no power control solution, then power aware scheduling is applied. Alternatively, only power aware scheduling is utilized.

Abstract: A method of providing medium access control for a wireless mobile ad hoc network includes defining a TDMA network timing frame including a data (DATA) zone having one or more time slots structured to support multiuser detection (MUD) of concurrent transmissions during each slot, a negative acknowledgment (NACK) zone during which nodes transmit requests for retransmission of packets destined to but not successfully received by the nodes, a broadcast (BC) zone during which network management messages are broadcast to the nodes, and a control (CTRL) zone. A primary master (PM) node is selected and operates as a source of network time for all the nodes. Each node synchronizes its time to that of the PM node during the CTRL zone in a distributed manner, by exchanging control messages with the PM node or other nodes located one or more hops from the PM node.

Abstract: In the method for operating an interference multiple access communications system, wherein the improvement comprises the steps of employing a distributed scheduler within a Media Access Controller (MAC) for Multiuser Detection (MUD) enabled Mobile Ad-hoc Networks (MANETS) to increase spectral efficiency by increasing spectral use and providing a way to dynamically allocate virtual channels to achieve maximum channel reuse in different network topologies and different link patterns and to ameliorate any hidden or exposed node problems.

Abstract: A system and method of reducing or eliminating training for adaptive receiver and neural networks is disclosed. The adaptive filter or neural network is pre-training using simulation or empirically received data and a took-up table is created. Coefficient instantiation from the receiver for ail permutations of the key parameters of training data are stored along with the key parameters within the look-up table. After creating the look-up table, the key parameters of the signal to be decoded are estimated. The coefficient of filter or neural network for the estimated key parameters is obtained by accessing the loop-up table. The demodulated signal is produced by setting the filter or neural network coefficents to coefficient values obtained from the look-up table. For slow varying key parameters, the coefficients from the lookup table are occasionally replaced instead of implementing the adaptive filter or neural network.

Abstract: A QR-RLS adaptive digital filter provides fast computation without excessive computational resources. 18-bit multipliers enhance speed, and a floating point inverse square root block adjusts dynamic range in 12-dB steps. A memory stores two P-matrix copies, one being delivered with rows shifted according to the clock speed so as to enhance pipeline processing. Embodiments reliably detect modulation schemes, demodulate strong signals by passing feedback bits between multiple stages, remove impulses due to lightening, etc, erase symbol estimates which exceed an error threshold, and add high frequency noise to avoid mathematical divergence caused by excessive S/N. A genetic method is provided for identifying asynchronous spreading codes with minimum correlations, whereby randomly selected candidates compete based on Frobenius norms of their correlations, the weakest being discarded and the process being iterated.

Abstract: A method of providing medium access control for a wireless mobile ad hoc network includes defining a TDMA network timing frame including a data (DATA) zone having one or more time slots structured to support multiuser detection (MUD) of concurrent transmissions during each slot, a negative acknowledgment (NACK) zone during which nodes transmit requests for retransmission of packets destined to but not successfully received by the nodes, a broadcast (BC) zone during which network management messages are broadcast to the nodes, and a control (CTRL) zone. A primary master (PM) node is selected and operates as a source of network time for all the nodes. Each node synchronizes its time to that of the PM node during the CTRL zone in a distributed manner, by exchanging control messages with the PM node or other nodes located one or more hops from the PM node.

Abstract: In the method for operating an interference multiple access communications system, wherein the improvement comprises the steps of employing a distributed scheduler within a Media Access Controller (MAC) for Multiuser Detection (MUD) enabled Mobile Ad-hoc Networks (MANETS) to increase spectral efficiency by increasing spectral use and providing a way to dynamically allocate virtual channels to achieve maximum channel reuse in different network topologies and different link patterns and to ameliorate any hidden or exposed node problems.

Abstract: What is provided is a system for maintaining acceptable error rates in a MUD-enabled ad-hoc network. In this system the power spread associated with all of the nodes is maintained within the dynamic range of the system, for instance 30 dB. Also, the signal-to-noise ratio at an intended receiver is maintained above a predetermined minimum SNR, for instance above 5 dB. If the dynamic range rule is not met, then the power at the transmitting node is attenuated such that the dynamic range rule is met, checking to see that the minimum SNR rule is also met, or the transmission from this node is pulled. If there is no power control solution, then power aware scheduling is applied. Alternatively, only power aware scheduling is utilized.

Abstract: A QR-RLS adaptive digital filter provides fast computation without excessive computational resources. 18-bit multipliers enhance speed, and a floating point inverse square root block adjusts dynamic range in 12-dB steps. A memory stores two P-matrix copies, one being delivered with rows shifted according to the clock speed so as to enhance pipeline processing. Embodiments reliably detect modulation schemes, demodulate strong signals by passing feedback bits between multiple stages, remove impulses due to lightening, etc, erase symbol estimates which exceed an error threshold, and add high frequency noise to avoid mathematical divergence caused by excessive S/N. A genetic method is provided for identifying asynchronous spreading codes with minimum correlations, whereby randomly selected candidates compete based on Frobenius norms of their correlations, the weakest being discarded and the process being iterated.