CHRISTOPHER DOUGLAS MOFFATT
Pilots in Melbourne, FL

8175178, May 8, 2012

Oct 1, 2008

12/242958

Christopher D. Moffatt - Palm Bay FL, US
John E. Hoffmann - Indialantic FL, US

Harris Corporation - Melbourne FL

H04K 1/10, H04L 27/00

375260, 375259

A communications device includes communications data and a training sequence corresponding to a preamble. A modulation and mapping circuit modulates the communications data and training sequence into a plurality of multiple subcarriers that are orthogonal to each other to form an OFDM communication signal having modulated subcarriers carrying the communications data forming a data payload and modulated subcarriers forming the preamble. A circuit turns OFF and ON selected subcarriers based on an encryption algorithm to increase transmit power and signal-to-noise ratio and reduce the Inter-Carrier Interference (ICI). The modulation and mapping circuit applies a quadratic modulation to the subcarriers carrying the training sequences to produce a low peak-to-average power ratio (PAPR) preamble with a PAPR value of approximately 2. 6 decibels (dB).

7822136, Oct 26, 2010

Oct 6, 2009

12/574386

Christopher Douglas Moffatt - Palm Bay FL, US
Ray J. Kolar - Grant FL, US
Charles W. Richards - Melbourne FL, US

Harris Corporation - Melbourne FL

H04L 27/28

375260, 375296

The present disclosure presents a predictive signal producing method that effectively levels transmitter output power in a multi-carrier communication system and results in approaching amplifier performance normally associated with constant carrier waveforms. Embodiments of the disclosed solution offers >10 dB reduction in the peak-to-average power required to support the transmission of, for example, orthogonal frequency division modulation (“OFDM”) modulation techniques. Embodiments of the novel system and method maximize peak-to-average power ratio (“PAPR”) reduction with selective mapping and soft clipping, which may include filtering, combined. This novel approach also minimizes overhead, bit error rate, retransmissions, and increases latency as well as implementing processing cycles with a number of iterations. The disclosed system and method improves the total system DC power efficiency and provides an optimal solution for PAPR reduction in multi-carrier communication systems such as, for example, OFDM.

8165232, Apr 24, 2012

Oct 1, 2008

12/242952

Christopher D. Moffatt - Palm Bay FL, US
John E. Hoffmann - Indialantic FL, US

Harris Corporation - Melbourne FL

H04K 1/10

375260, 375259, 375261, 375271

A communications device includes communications data and a training sequence corresponding to a preamble. A modulation and mapping circuit modulates the communications data and training sequence into a plurality of multiple subcarriers that are orthogonal to each other to form an orthogonal frequency division multiplexing (OFDM) communications signal having modulated subcarriers carrying the communications data forming a data payload and modulated subcarriers forming the preamble. The modulation and mapping circuit applies a quadratic modulation to the subcarriers carrying the training sequences to produce a low peak-to-average power (PAPR) preamble of approximately 2. 6 decibels (dB) independent of the number of subcarriers.

7555013, Jun 30, 2009

Aug 12, 2002

10/216278

Thomas Jay Billhartz - Melbourne FL, US
Travis Lee Berrier - Melbourne FL, US
Christopher Douglas Moffatt - Palm Bay FL, US

Harris Corporation - Melbourne FL

H04J 3/06, H04L 12/28

370503, 370255

A method and system for achieving synchronization at a local site to a wireless communication system transmitting data in a plurality of data packets distributed among a plurality of frequencies alternating in a sequence determined in accordance with at least two characteristics of said remote site by blindly determining at least one of said two characteristics are disclosed. The method comprises the steps of recording a plurality of occurrences of a selected one of the plurality of frequencies, determining the at least one first characteristic from at least one of the data packets, determining locally the at least one second characteristic wherein the determined at least one first characteristic and the at least one second characteristic match the selected frequency at each of the recorded detected occurrences, determining a time period for determining the first and second characteristics; and adjusting the at least one second characteristic by the time period.

8160166, Apr 17, 2012

Oct 1, 2008

12/242989

Christopher D. Moffatt - Palm Bay FL, US
John E. Hoffmann - Indialantic FL, US

Harris Corporation - Melbourne FL

H04K 1/10

375260, 375259, 375267

A communications device includes a demapping and demodulation circuit and processes an OFDM communications signal that includes modulated subcarriers carrying communications data forming a data payload and modulated subcarriers carrying a training sequence forming a preamble. Those OFDM subcarriers carrying the training sequence have a sample for each subcarrier at a frequency bin using evenly spaced, equal amplitude subcarriers that have a set phase of each sinusoid to a specific angle with quadratic phase to form a low peak-to-average power ratio (PAPR) preamble with about a PAPR value of 2. 6 decibels (dB). A channel estimate circuit is operative for measuring fluctuations within a flat-top spectrum of the received OFDM communications signal corresponding to the preamble to reflect the frequency response of the communications channel.

7639747, Dec 29, 2009

Oct 23, 2003

10/690613

Christopher Douglas Moffatt - Palm Bay FL, US
Ray J. Kolar - Grant FL, US
Charles W. Richards - Melbourne FL, US

Harris Corporation - Melbourne FL

H04L 27/28

375260, 375296

The present disclosure presents a predictive signal producing method that effectively levels transmitter output power in a multi-carrier communication system and results in approaching amplifier performance normally associated with constant carrier waveforms. Embodiments of the disclosed solution offers >10 dB reduction in the peak-to-average power required to support the transmission of, for example, orthogonal frequency division modulation (“OFDM”) modulation techniques. Embodiments of the novel system and method maximize peak-to-average power ratio (“PAPR”) reduction with selective mapping and soft clipping, which may include filtering, combined. This novel approach also minimizes overhead, bit error rate, retransmissions, and increases latency as well as implementing processing cycles with a number of iterations. The disclosed system and method improves the total system DC power efficiency and provides an optimal solution for PAPR reduction in multi-carrier communication systems such as, for example, OFDM.

8160165, Apr 17, 2012

Oct 1, 2008

12/242976

Christopher D. Moffatt - Palm Bay FL, US
John E. Hoffmann - Indialantic FL, US

Harris Corporation - Melbourne FL

H04K 1/10

375260, 375259, 375261, 375271

A communications device includes communication data and a training sequence corresponding to a preamble. A modulation and mapping circuit modulates the communications data and training sequence into a plurality of multiple subcarriers that are orthogonal to each other to form an OFDM communications signal having modulated subcarriers carrying the communications data forming a data payload and modulated subcarriers forming the preamble. A pseudo-random signal generator is operative with the modulation and mapping circuit and generates pseudo-random signals based on an encryption algorithm for frequency hopping each subcarrier at an OFDM symbol rate. The modulation and mapping circuit applies a quadratic modulation to the subcarriers carrying the training sequences to produce a low peak-to-average power ratio (PAPR) preamble with a PAPR value of approximately 2. 6 decibels (dB).

7860147, Dec 28, 2010

Aug 16, 2006

11/464868

Christopher D. Moffatt - Palm Bay FL, US

Harris Corporation - Melbourne FL

H04B 1/00

375132, 375260, 375261, 375268, 375297, 375298, 375300, 375324, 375348, 375349

A system and method communicates and generates a Coded Orthogonal Frequency Division Multiplexed (COFDM) communications signal as a plurality of subcarriers. Selected subcarriers are turned ON and OFF while also frequency hopping and spreading the selected ON subcarriers over the frequency domain based on a fixed or variable sample rate to reduce average power for enhanced Low Probability of Interception/Low Probability of Detection (LPI/LPD) and also allow for more transmit power within a spectral mask.

8619908, Dec 31, 2013

Dec 2, 2009

12/629584

John E. Hoffmann - Indialantic FL, US
Carlos G. Abascal - Melbourne FL, US
Christopher D. Moffatt - Palm Bay FL, US

Harris Corporation - Melbourne FL

H04L 27/00

375299, 375260, 375267, 375340, 370203, 370208, 370210, 455101, 455102, 4554561, 4554562, 342107, 342128, 342129, 342133, 342192, 342194, 342196, 342385, 342453, 342457, 342458, 34053913, 702158, 702159

A wireless ranging system for determining a range of a remote wireless device may include a wireless transmitter and a wireless receiver. The wireless ranging system may also include a ranging controller to cooperate with the wireless transmitter and receiver to generate a multi-carrier base waveform, transmit a sounder waveform to the remote wireless device including concatenated copies of the multi-carrier base waveform, and receive a return waveform from the remote wireless device in response to the sounder waveform. The ranging controller may also generate time domain samples from the return waveform, convert the time domain samples into frequency domain data, and process the frequency domain data to determine the range of the remote wireless device.

7642850, Jan 5, 2010

Apr 2, 2008

12/061013

G. Patrick Martin - Merritt Island FL, US
Christopher D. Moffatt - Palm Bay FL, US
James Tonti - Valkaria FL, US

Harris Corporation - Melbourne FL

H03F 1/26

330151

RF amplifier system () incorporating feedforward linearization. The system includes a digital waveform source () generating digital data s(t) representative of at least one analog signal. The system also includes a feedforward linearization circuit for reducing a distortion of an RF power amplifier (). The feedforward linearization circuit includes a differential amplifier () arranged for generating an error signal. The error signal is determined based on a difference between the distorted RF output signal and an analog RF reference signal () generated from the digital data.