Abstract: A digital signal processing (DSP) apparatus is used for processing a plurality of different signals. The DSP apparatus includes a DSP module configured to perform a DSP algorithm on samples of the signals. The DSP apparatus also has a parameter memory that includes a plurality of memory cells. The parameter memory has a signal number input and a parameter output. The parameter output is connected to the DSP module. The parameter memory is configured to output to the parameter output a parameter corresponding to a signal identifier at the signal number input.

Abstract: A wedge shaped scimitar radio frequency (RF) antenna can include a lip, an RF signal feed connected to the lip, a base, and a back surface. The antenna can also include a convexly curved outer surface that extends from the lip to the back surface. The convexly curved outer surface can be wedge shaped from the back surface of the antenna to the lip. The antenna can also include a concavely curved outer surface that extends from the lip to the base of the antenna, and the concavely curved outer surface can be wedge shaped from the base of the antenna to the lip.

Abstract: The peak-to-average power ratio of an input signal can be reduced prior to amplification. This reduction in the peak-to-average power ratio can be accomplished without adding significant intermodulation distortion to the input signal. The resulting input signal can therefore have a peak-to-average power ratio that does not exceed the output backoff of the amplifier thereby preventing the amplifier from being operated in saturation and, as a result, minimizing the intermodulation distortion added by the amplifier. The peak-to-average power ratio of an input signal can be reduced using two stages of signal clipping. By employing two stages, the intermodulation distortion introduced to the input signal as it passes through the stages is minimized. Also, because this two-stage approach does not attempt to account for intermodulation distortion introduced by the downstream amplifier, it can be implemented without any prior knowledge of the amplifier's transfer function or any output monitoring scheme.

Abstract: Methods and systems are disclosed for testing and/or validating that an untrusted device is operating according to an expected state or configuration. The methods and systems may be designed such that the volatile memory of the untrusted device is brought to a known state for validation, for example upon ingress to or egress from a protected mode of operation. The device may execute a first operating system when operating outside of the protected mode. Upon determining to transition to protected mode, an operational image of a second operating system may be loaded into the device. The device may write a pattern to unused memory for validation. The device may receive a first challenge request from a trusted monitor (TM). In order to be successfully validated, the device may answer the challenge correctly within a given response window based on the current state of its volatile memory.

Abstract: A system and method for training a student employ a simulation station that displays output to the student and receives input. The computer system has a rules engine operating on it and computer accessible data storage storing (i) learning object data including learning objects configured to provide interaction with the student at the simulation system and (ii) rule data defining a plurality of rules accessed by the rules engine. The rules data includes, for each rule, respective (a) if-portion data defining a condition of data and (o) then-portion data defining an action to be performed at the simulation station. The rules engine causes the computer system to perform the action when the condition of data is present in the data storage. For at least some of the rules, the action comprises output of one of the learning objects so as to interact with the student. The system may be networked with middleware and adapters that map data received over the network to rules engine memory.

Abstract: Systems and methods that may be implemented to provide digital data from a remote information source to multiple local user devices using a multi-layer communication path and a local wireless server node. The multi-layer communication path may, for example, include a relatively long range secure first layer wireless communications path from the remote information source to a local wireless server node, and relatively short range second layer wireless communications path from the local wireless server node to one or more local user devices.

Abstract: A digital electronic message comprising datawords to be transmitted in a communications system can be encoded prior to transmission using an asymmetric error detection coding scheme. The coding scheme is asymmetric because the coding scheme includes multiple codeword groups each with a different minimum coding distance. The codewords in a group having a greater minimum coding distance can correspond to datawords that have a relatively high susceptibility to transmission errors. The codewords in a group having a lesser minimum coding distance can correspond to datawords that have a relatively low susceptibility to transmission errors.

Abstract: A radio signal reception technique includes selecting a sample rate from a plurality of predefined sample rates so that the radio signal is contained entirely within a Nyquist zone corresponding to the sample rate. The radio signal is passed through a selected one of a plurality of selectable bandpass filters to provide an analog signal. The analog signal is sampled at the sample rate and converted to a digital signal.

Abstract: A symbol de-mapper can determine soft values for the bits of a complex symbol R that has been transmitted and received at a receiving device. The symbol de-mapper can reduce the number of calculations needed to determine soft values of the bits by limiting the symbols S utilized to calculate the soft values to subsets of the symbols S associated with sectors of symbol rings in the symbol constellation.

Abstract: Embodiments of strain-balanced superlattice infrared detector devices and their fabrication are disclosed. In one embodiment, an infrared detector device includes a first contact layer, and absorber superlattice region, a wider gap unipolar barrier region, and a second contact layer. The absorber superlattice region has a period defined by a first InAs layer, strain-balancing structure, a second InAs layer, and an InAsSb layer. The strain-balancing structure comprises an arbitrary alloy layer sequence containing at least one constituent element of aluminum or phosphor, e.g., InGaAs, AlInAs InAsP. In another embodiment, the absorber superlattice region has a period defined by a first InAs layer, first strain-balancing structure, a second InAs layer, a first GaSb layer, a second strain-balancing structure, and a second GaSb layer. The first strain-balancing structure includes at least one constituent element of aluminum or phosphor, e.g., InGaAs, AlInAs InAsP.

Abstract: Methods and systems for increasing the security or trust associated with an untrusted device are provided. For example, a trusted hardware component may send a request to the untrusted device. The request may indicate one or more challenges to be performed by a secure application executing on the untrusted device. The trusted hardware component may determine an expected response to the one or more challenges. The expected response may be determined at the secure hardware component based on an expected configuration of the untrusted device. The trusted hardware component may receive a response to the request from the untrusted device. The trusted hardware component may determine a security status of the untrusted device based on the expected response and the received response.

Abstract: A galvanically isolated DC/DC converter includes a first and a second side converter circuit coupled between a pair of first side DC terminals and a pair of second side DC terminals, respectively. The first side converter circuit has a first and a second switching element, each including a switch and a diode. When the DC/DC converter is in power transfer operation from the second side DC terminals to the first side DC terminals, the second side converter circuit alternates between two power transfer states. A conductive state of the diode of one of the first and second switching elements is the result of one of the two power transfer states. The first side converter circuit is controlled such that the switch of the respectively other of the first and second switching elements is closed for an adaptation interval before the one of the two power transfer states starts.

Abstract: Effective atomic numbers associated with pixels in a region are received. An effective atomic number is associated with each pixel in the region. X-ray data for the region is received, and an item within the region is identified from the x-ray data. Some of the pixels in the region are correlated with the item such that the item is associated with an effective atomic number. An image of the region is rendered. The pixels of the item have a display style based on the effective atomic number of the item.

Abstract: Diode barrier infrared detector devices and superlattice barrier structures are disclosed. In one embodiment, a diode barrier infrared detector device includes a first contact layer, an absorber layer adjacent to the first contact layer, and a barrier layer adjacent to the absorber layer, and a second contact layer adjacent to the barrier layer. The barrier layer includes a diode structure formed by a p-n junction formed within the barrier layer. The barrier layer may be such that there is substantially no barrier to minority carrier holes. In another embodiment, a diode barrier infrared detector device includes a first contact layer, an absorber layer adjacent to the first contact layer, a barrier layer adjacent to the absorber layer, and a diode structure adjacent to the barrier layer. The diode structure includes a second contact layer.

Abstract: A digital signal processing (DSP) apparatus can be used to process a serial stream of digital signal samples of a plurality of “n” number of different signals. The DSP apparatus can include a DSP module configured to perform a DSP algorithm on digital signal samples of the signals. The DSP apparatus can have a delay memory with an “n” number of memory cells that each corresponding to one of the signals. The delay memory can also have a digital signal sample input connected to said initial input of said DSP module, a signal-number-in input, a signal-number-out input, and a digital signal sample output connected to said delay input of said DSP module. The delay memory can be configured to store a digital signal sample at the digital signal sample input in a memory cells identified by a signal identifier at said signal-number-in input.

Abstract: Systems and methods are disclosed for locating signal wave (SW) emitter/s using at least one moving signal collection platform. The disclosed systems and methods may be employed in one embodiment to estimate the signal energy transmitted from a grid of locations (such as a map) using collected IQ data (or other raw data representation such as IQ data covariance matrix), and without requiring computation of any intermediate geolocation-observable measurements (such as angle-of-arrival, direction-of-arrival, etc.). In a further embodiment, the disclosed systems and methods may be implemented in a blind manner (i.e., transmitted emitter signal/s are unknown and processed blindly) to geolocate SW emitters using a single SW signal collection platform (e.g., at relatively large standoff distances in some implementations) without relying on a known signal modulation or operation of multiple simultaneous SW signal collection platforms.

Abstract: Adaptive filtering is used to substantially cancel distortion in radio frequency (RF) signals. Such adaptive filtering can be used in an RF transmitting module to pre-compensate an RF signal with compensation (inverse) distortion to cancel inherent transmission path distortion from the RF signal. Adaptive filtering can also be used in a multi-carrier RF receiving module to cancel from a given carrier signal distortion due to cross talk from adjacent carrier signals. Adaptive filtering in an RF transceiver can be used to cancel from a received RF signal distortion arising from leakage of a transmit signal into the receive path.

Abstract: Stepped radio frequency (RF) reflector antennas are disclosed in which an inner RF reflector is disposed in a central opening of at one or more annular RF reflectors. The RF reflecting surface of the inner RF reflector and the RF reflecting surface(s) of the one or more annular RF reflectors can be shaped and positioned relative to each other to have different focal lengths but nevertheless reflect an RF signal to the same focal plane. The depth of the inventive reflector antenna system can be less than the depth of prior art reflector antennas with a comparable RF aperture.

Abstract: Systems and methods that may be implemented to determine the location of an emitter of electromagnetic radiation having an unknown location, using a cooperative TDOA-based location methodology. The cooperative TDOA-based location methodology (e.g., such as TDOA/TDOA, TDOA/FDOA, etc.) may be implemented using at least one cooperative transmitter that transmits a cooperative electromagnetic (EM) signal from a known location that is received at multiple different EM sensing platforms that are also each of known location. The known geolocation of the cooperative transmitter may be used to resolve the signal arrival timing relationships between the different sensing platforms that is utilized to determine the location of another EM transmitter of unknown location.

Abstract: An interference channel equalizer for receiving and processing at least two distinct RF data signals transmitted over the same frequency to a single receiving station that has at least one receiver for each distinct transmitted RF data signal. Each receiver processes an RF data signal received by its antenna and outputs an output data signal which corresponds to one of the distinct transmitted RF data signals. Each receiver includes an antenna configured to receive an RF data signal, a demodulator, a delay block to selectively delay the received RF data signal, an interference cancellation feed forward filter that uses the received signal from another receiver to remove co-channel due to another distinct RF transmitted data signal from the signal being processed, and a decision feedback equalizer to mitigate both intersymbol and multi-path interference from the received signal being processed.