Rockwell Collins, Inc.

Carlos J Chavez

Robert J Frank

Michael N Newhouse

Gunther B Frank

Jason A Fuemmeler

W Sam Spencer

Shubha L Kadambe

Gina M Reyes

Sasha N Oster

Carlen R Welty

Dennis L Hoffman

Richard L Robertson

Scott J Zogg

Scott J F Zogg

Ryan M Murphy

Vadim Olen

Karl F Hoech

Michael R Vagher

Benjamin J Haan

Bruce S Kloster

Mark W Barglof

Kent D Benson

Erik M Sjolander

William S Spencer

Shubba L Kadambe

Allan J Hammell

Robert K Fahler

Patrick J Murphy

A system and method for signal cross-correlation using adaptive polar quantization and polar multiplication is disclosed. The method includes receiving a first and second complex signal. The method includes computing a first quantized phase and a first quantized magnitude based on a first adaptive polar quantization of a sample of the first complex signal and computing a second quantized phase and a second quantized magnitude based on a second adaptive polar quantization of a sample of the second complex signal. The method includes computing a polar multiplication based on the first quantized phase, the first quantized magnitude, the second quantized phase, and the second quantized magnitude to generate a rotated quantized phase and a multiplied quantized magnitude; converting to component real and imaginary parts; and computing a sum using complex addition.

Efficient cross-correlation with adaptive polar quantization

A receiver system for correlating one or more signals (beam patterns) is disclosed. One or more antenna elements are configured to receive the signals. A controller generates correlator outputs based on a first set of duplicated signals, generates a first set of beams based on the one or more correlator outputs using a first beamforming module, generates a second set of beams based on a second set of duplicated signals using a second beamforming module, generates one or more power estimates based on the second set of beams, and divides each of the first set of beams by a corresponding power estimate to generate one or more normalized correlations.

Technique for post-correlation beamforming

A spread-spectrum transmitter is disclosed. The transmitter includes a modulator configured to produce an intermediate frequency signal, a frequency shifter configured to shift the intermediate frequency factor by a first factor, and a local oscillator (LO) configured to generate a LO signal. The transmitter further includes a ramp signal generator configured to determine the value of the first factor and a second factor, is configured to transmit the value of the factor to the frequency shifter, is configured to transmit the value of the second factor to the LO, where the frequency of the intermediate frequency signal shifted by the first factor is shifted synchronously with the frequency of the LO signal shifted by the second factor. The transmitter includes a mixer configured to mix the shifted intermediate frequency with the shifted LO signal that has been shifted by the second factor, producing a spread leaked LO signal.

Fast local oscillator tuning transmitter

A receiver system for demodulating a high-entropy continuous phase modulation (HE-CPM) signal is disclosed. A plurality of complex multipliers is configured to receive the synchronized HE-CPM signal. Each of the complex multipliers removes a phase associated with a respective one of a plurality of inter-symbol interference (ISI) hypotheses and generates a respective one of a plurality of complex multiplier outputs. Each ISI hypothesis includes a previous chip hypothesis corresponding to a binary value for a previous chip, and a next chip hypothesis corresponding to a binary value for a next chip. A summer is configured to combine real parts of the plurality of complex multiplier outputs to generate a soft decision for a current chip of the HE-CPM signal.

Technique for efficient soft-decision demodulation of HE-CPM

A system for determining a geographical position of a transmitting device is disclosed. In embodiments, the system includes a concentrator device and a plurality of sensors. In embodiments, each sensor may be configured to: receive an emitter signal from a transmitting device; generate a demodulated sequence of the emitter signal; generate a time-of-arrival (TOA) estimate of the emitter signal; and transmit the demodulated sequence and the TOA estimate to the concentrator device. In embodiments, the concentrator may be configured to: receive a first demodulated sequence and a first TOA estimate (TOA) from a first sensor; receive a second demodulated sequence and a second TOA estimate (TOA), from a second sensor; determine a first arbitrary timing offset (ATO) between the first demodulated sequence and the second demodulated sequence; and determine a first differential TOA estimate (TOA) between the first sensor and the second sensor.

System and method for blind differential time-of-arrival estimation

A communication device may include a communication interface configured to receive signals and a controller configured to: receive an input signal based on the received signals; perform transform operations on the input signal to generate a spectral periodogram of the input signal; calculate spectral vector powers for each bin of a plurality of bins of the spectral periodogram; determine a median spectral power for a selected range of bins of the plurality of bins; generate a median-scaled spectral density vector based on the median spectral power and a reference spectral density of an expected signal; calculate a detection threshold vector based at least in part on the median-scaled spectral density vector; and identify one or more interference-including bins of the plurality of bins of the spectral periodogram by comparing the spectral vector powers for each bin of the plurality of bins to the detection threshold vector.

System and method for robust interference detection

System for generating a constant envelope and suppressed cyclic feature signal may include a transmission security (TRANSEC) function, a spread spectrum chip, an M-ary continuous phase modulator, and a pulse-shaped filter. The TRANSEC may generate a pseudorandom symbol by M-ary symbol generation selects a symbol with a signal phase, and the spread spectrum chip corresponding to the generated pseudorandom symbol or a phase rotation of the pseudorandom symbol. The M-ary continuous phase modulator with a delta-phase mapper maps the signal phase based at least in part on the selected symbol. The pulse-shaped filter of the M-ary modulator introduces inter-symbol interference from a previous and a subsequent symbol into a current symbol; the inter-symbol interference may be introduced by the main lobe of the signal phase being contained within a bandwidth of a chip rate of the spread spectrum chip for frequency modulation signal transmission of information by the generated signal.

High-entropy continuous phase modulation data transmitter

In embodiments, a communication node of a multi-node communication network includes a controller communicatively coupled to a communication interface, wherein the controller is configured to: acquire a data payload to be transmitted based on a randomized transmission interval; duplicate a bit sequence of the data payload with a selected spreading pattern; perform bit-to-symbol mapping of the bit sequence based on a selected M-ary number to generate a data payload symbol sequence; randomize a location or value of one or more pilot symbols and one or more data carriers of the data payload symbol sequence; transform frequency-domain symbols of the data payload symbol sequence into time-domain symbols to generate a time-domain data payload signal; remove amplitude fluctuation of the data payload signal to generate a phasor data payload signal; and transmit the phasor data payload signal to at least one additional communication node of the multi-node communication network.

System and method for low probability of detection and low probability of intercept waveform

System and methods for generating and employing coherent multicarrier correlation can include receiving, from a transmitter, a plurality of radio frequency (RF) signals associated with a respective plurality of nominal carrier components. A processing circuitry can remove from each received RF signal the respective nominal carrier component to generate a corresponding baseband signal. The processing circuitry can generate, for each baseband signal, a respective correlation signal using the baseband signal and a reference signal. The processing circuitry can incorporate, to each correlation signal, the respective nominal carrier component of the RF signal associated with that correlation signal to generate a respective single-carrier correlation signal. The processing circuitry can aggregate the single-carrier correlation signals to generate a multi-carrier correlation signal. The processing circuitry can determine one or more attributes of the transmitter or the received RF signals based on the generated multi-carrier correlation signal.

Efficient technique for coherent multicarrier correlation

A method for pseudomorphic modulation to mimic a particular type of Radio Frequency (RF) signal transmission in an RF environment may include selecting a physical modulation scheme that is utilized for RF signal transmission in the RF environment. The method may also include pseudorandomly generating a plurality of symbols associated with the physical modulation scheme. The method may further include receiving encoded data for transmitting in the RF environment. The method may also include pseudomorphically modulating the encoded data by mapping the encoded data to the plurality of pseudorandomly generated symbols.

Pseudomorphic modulation for RF signal transmission

Disclosed is an apparatus for estimating the features of a radio frequency signal including a reference signal generator configured for generating a reference signal from a complex signal and one or more feature estimation units configured to generate one or more feature estimates from the reference signal and the complex signal. Techniques for creating reference signals from both signals spread by a scrambling code and FM signals are discussed.

Referenced-based radio frequency feature estimation

An apparatus and method for signal separation and SINR improvement is disclosed. In particular, disclosed is an iterative technique whereby a noisy signal, that may include signals from one or more distinct emitters, is first improved through an SINR improvement technique. Next, one signal from the noisy signal is identified and a reference signal substantially free of noise and interference is generated for this signal, and then this reference signal is subtracted from the noisy signal. This process is repeated until no other signals may be identified. In this way, the signal with the highest SINR may be identified first and then removed from the original signal. As such, the identified signal is no longer present as interference for the remaining signals, thus improving each of the remaining signals' respective SINRs.

Signal separation and SINR enhancement

An apparatus for identifying a specific emitter in the presence of noise and/or interference is disclosed. The apparatus includes a sensor configured to sense radio frequency signal data, the signal data containing noise and signal from at least one emitter, a reference estimation unit configured to estimate a reference signal relating to the signal transmitted by one emitter, a feature estimation unit configured to generate one or more estimates of one or more feature from the reference signal and the signal transmitted by that particular emitter, and an emitter identifier configured to identify the signal transmitted by that particular emitter as belonging to a specific device using one or more feature estimates. The emitter identifier identifies the signal transmitted by that particular emitter as belonging to a specific device using Gaussian Mixture Models and the Bayesian decision engine.

System for specific emitter identification

An apparatus for sensing and classifying radio communications is provided. The apparatus includes one or more sensor units configured to detect radio frequency signals, a signal classifier configured to classify the detected radio frequency signals into a classification, the classification including at least one known signal type and an unknown signal type, a clustering learning algorithm capable of finding clusters of common signals among the previously seen unknown signals. The system is then further configured to use these clusters to retrain the signal classifier to recognize these signals as a new signal type.

Cognitive networked electronic warfare

Methods and systems for signal quantization may include, but are not limited to: receiving a complex signal characterized by a real portion and an imaginary portion; computing a vector magnitude of a sample of the complex signal; comparing the vector magnitude of the sample to a quantization threshold value; and associating a quantized magnitude with the sample according to a comparison between the vector magnitude of the sample and the quantization threshold value.

Growing community of inventors

Marion, IA, United States of America

Carlos J Chavez