L-3 Communications Corporation

L3harris Technologies, Inc.

Other

L3 Technologies, Inc.

L-3 Communciations Corp.

Osama Sami Haddadin

William K McIntire

Samuel Charles Kingston

David S Nelson

L Andrew Gibson

Brad Terry Hansen

Ryan W Hinton

Janez Jeraj

Robert G Rebolledo

Roy E Prymek

Thomas R Giallorenzi

Brandon Gregory Walsh

Johnny M Harris

Eric K Hall

Francis James Smith

Zachary C Bagley

James Dyal

Jonathan C Landon

Tom R Giallorenzi

Dan Watt

Roland Richard Henrie

Joseph D Spencer

Rebekah Reeder

Radivoje Zarubica

David G Landon

Seth John Thorup

Andrew L Nelson

Nicholas T Yaskoff

Teren G Jameson

Marc Padilla

Matthew A Lake

Michael D Pulsipher

Roland R Henne

Patrick M Ryan

Boston C Terry

Armin Hedzic

Scott N Adamson

Justin Petersen

Aurora Taylor-Rojas

Timothy D Jones

Scott Talbot

A radio frequency (RF) system may include at least one RF sensor in an RF environment and at least one RF actuator. The RF system may also include at least one processor that includes a machine learning agent configured to use a machine learning algorithm to generate an RF model to operate the at least one RF actuator based upon the at least one RF sensor. The processor may also include a recommendation training agent configured to generate performance data from the machine learning agent, and change the RF environment based upon the performance data so that the machine learning agent updates the machine learning algorithm.

Recommendation training agent for machine learning algorithm and related methods

Communicating using spread spectrum. A legacy RF signal is intercepted from a legacy radio. Spread spectrum processing is performed on the legacy RF signal to create a spread signal. The spread signal is transmitted to a receiver, whereafter the spread signal is de-spread to recover the legacy RF signal.

Tactical/legacy waveform obfuscation through independent spreading overlay

A digitally controlled analog filter device. The digitally controlled analog filter device includes one or more digitally controlled analog signal amplifiers. The digitally controlled analog signal amplifiers are configured to have a gain of the digitally controlled analog signal amplifiers controlled by digital signals. The digitally controlled analog filter device further includes one or more analog time delay circuits coupled to signal input nodes of the digitally controlled analog signal amplifiers. The analog time delay circuits are configured to implement an analog signal delay. The digitally controlled analog filter device further includes a digital closed loop control circuit coupled to the digitally controlled analog signal amplifiers to digitally control the gain of the digitally controlled analog signal amplifiers.

Time-adaptive RF hybrid filter structures

A transmit signal can be distorted with non-linear distortion, and one or more characteristics of the non-linear distortion can be periodically changed in accordance with a change key. The transmission received at a receiver can thus comprise a severely distorted version of the transmission of the transmit signal. A receiver with the same change key can recognize and decode the transmission, but it can be extraordinarily difficult for receivers that lack the change key to detect and decode the transmission. The transmission can be a communications while jamming (CWJ) transmission. The CWJ transmission can contain a coded message that can be decoded only by friendly RF receivers, and the CWJ transmission can also jam unfriendly RF receivers that lack a change key for decoding the coded message.

Combining time-varying non-linear distortion with a communications signal

Embodiments are directed to synchronizing time among nodes in a network. In one scenario, a first node receives a timing message which provides an indication of the current time as measured by a second node at transmission of the timing message. The first node determines the timing message propagation time between the first and second nodes using a determined transmission frequency of the timing messages, an internal clock reading of a clock that indicates the current time in the first node, and timing and frequency measurements obtained at the first and second nodes. The first node also applies a weighting factor to the current time of the first node to adjust the current time forward or backward, and combines the determined propagation time with the adjusted clock time of the first node to generate a new, synchronized time and transmission frequency, which is broadcasted to other nodes in the network.

Distributed network time synchronization using geo-beacons

An antenna system can impart orbital angular momentum (OAM) to an incident electromagnetic (EM) signal from a feed antenna. The antenna system can include a partial OAM antenna with a reflective surface that has only part of a full OAM shaped surface. The antenna system can thus reflect the incident EM signal as a partial OAM beam rather than a full OAM beam.

Antenna for transmitting partial orbital angular momentum beams

Electromagnetic (EM) feeds can illuminate a standard primary reflective antenna with a plurality of feed beams each having a different orbital angular momentum (OAM) or polarization. The reflective antenna, which can be a non-OAM antenna, can reflect the feed beams and thereby produce a composite OAM transmission comprising each of the feed beams. A non-OAM primary antenna can thus transmit a plurality of OAM feed beams as a composite OAM transmission.

Providing a non-zero orbital angular momentum feed beam to a reflective antenna

A method for receiving and removing co-channel interference from one or more received signals that comprise different symbol or chipping rates can comprise receiving a first composite signal and a second composite signal. The method can also comprise sampling the first composite signal and the second composite signal at a particular sampling rate that is sufficient to recover signal data from both the first composite signal and the second composite signal. Further, the method can comprise estimating from the second composite signal an estimated cross-coupled second signal within the first composite signal. The estimated cross-coupled second signal is estimated from at least the second composite signal at the particular sampling rate. Further still, the method can comprise recovering a substantially decoupled first data signal by removing at least a portion of the co-channel interference caused by the estimated cross-coupled second signal from the composite first signal.

Unequal rate interference cancellation

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.

Adaptive filtering for canceling distortion in radio frequency signals

A filter and method for finite impulse response filtering an input signal is described. In one embodiment, the filter includes an input circuit configured to receive input samples in parallel, where the parallel input samples correspond to sequential samples of the input signal. In another embodiment, the filter includes a coefficient memory configured to store filter response coefficients and output a subset of those coefficients corresponding to a selected decimation factor.

Finite impulse response filter with parallel input

A radio signal transmission 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. A digitized signal is converted to an analog signal, spectrally enhanced, and passed through a selected one of a plurality of selectable bandpass filters to form the radio signal.

Multi-band direct sampling transmitter

The perceived sample rate at which a DAC can operate can be increased by allowing multiple DACs to process different portions of a digital signal in parallel. In this way, the outputs of multiple DACs can be combined into a single analog signal to achieve the desired speeds and resolutions of the analog output. This parallel processing can be implemented using a time-interleaving technique or a sub-band reconstruction technique. Pre-distortion can be applied to the digital input signal to compensate for degradation detected in the analog output signal. By applying pre-distortion, waveforms having high sampling rates can be efficiently generated.

Time-interleaved and sub-band reconstruction approaches to digital-to-analog conversion for high sample rate waveform generation

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.

Multi-band direct sampling receiver

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.

Interference channel equalizer

Growing community of inventors

Salt Lake City, UT, United States of America

Osama Sami Haddadin