The Boeing Company

Isaac M Jeng

Brandon M Jones

David K Wen

Kamran Ghassemi

Reconstructing a partially obscured elliptical antenna dish image is provided. An image of an antenna dish contour with an obscured section is received, and a centroid for use as an origin reference is determined. Indices are sequentially assigned to samples along the contour starting with a sample having zero polar angle according to the origin reference. Sets of randomly selected N samples along the contour are prepared and used to perform least squares fit (LSF) to determine a cost function for each set. Cost functions with LSF residuals below a specified threshold show good quality-of-fit. An ensemble mean of the cost functions with good quality-of-fit is calculated. Outlier samples are identified according to local extrema for the ensemble mean. Samples having poor quality-of-fit of the ensemble mean between the extrema are considered outliers. Inlier samples are used to reconstruct the obscured section of the contour.

Reconstruction of obscured objects in segmentation maps

Methods, apparatus, systems and articles of manufacture to implement a signal scrambler are disclosed. An example method includes generating, by executing an instruction with a processor, a controlled random sequence based on a plurality of subcarriers and a random pulse sequence. The example method also includes forming, by executing an instruction with the processor, an output sequence by combining a source sequence with the controlled random sequence, the controlled random sequence to modify a characteristic of the source sequence in a frequency domain.

Methods and apparatus to implement a signal scrambler

Methods, apparatus, systems, and articles of manufacture to implement a third-order signal scrambler are disclosed. An example apparatus includes a controlled scramble generator to generate a controlled random sequence based on one or more subcarriers and a random pulse sequence, the random pulse sequence based on an output of a random number generator processed by a multi-order sinusoidal noise function. The example apparatus further includes a sequence modifier to form an output sequence by combining a source sequence with the controlled random sequence, the controlled random sequence to modify a characteristic of the source sequence in a frequency domain.

Methods and apparatus to implement a third-order signal scrambler

In accordance with one or more aspects of the present disclosure, a method for ranging of a PRN receiver including generating, at a PRN transmitting device that includes a processor and wireless transmitter and is in a line-of-sight position with the PRN receiver, at least two component codes, time shifting, with the processor of the PRN transmitting device, the at least two component codes relative to each other to form time shifted component codes, wirelessly transmitting, with the PRN transmitting device, the time shifted component codes to the PRN receiver with a predetermined modulation, and receiving the time shifted component codes with the PRN receiver that includes a PRN receiver processor, and determining a range estimate of the PRN receiver based on a combination of the time shifted component codes with the PRN receiver processor.

System and method for ranging a PRN receiver with a PRN composite code

Constant-envelope phase-optimized transmission methods and apparatus are disclosed. An example method includes determining initial values of modulation phases in a first quadrant, the modulation phases associated with binary codes to be transmitted; and optimizing the initial values to second values to enable a product of an objective function to be within a threshold value.

Constant-envelope phase-optimized transmission methods and apparatus

Methods and apparatus for generating composite code sequences are disclosed. An example method includes determining, via a determiner, a first number of samples to be contributed into a first unit duration of a composite code sequence from respective first, second, and third component code sequences; based on the first number of samples determined, randomly selecting, via a randomizer, the first number of samples from the respective ones of the first, second, and third component code sequences to enable the selected samples to more accurately represent the respective ones of the first, second, and third component code sequences; and compiling, via a compiler, the selected samples into the first unit duration of the composite code sequence by interspersing a sample from the first component code sequence between samples from the second component code sequence or between samples from the third component code sequence.

Methods and apparatus for generating composite code sequences

A method and apparatus for producing a transmission of constant envelope on a carrier signal. All possible combinations of all component codes for phases for producing the transmission are defined. Desired component code powers and desired intercode phases between all pairs of component codes are also defined. Still further, a portion of variables of a search process to reduce a number of variables searched by the search process is defined. Even further, deltas and weight variations for standard differences in a Jacobian matrix for use in the search process are defined. Penalty factors to evaluate an objective function of the search process are also defined. The search process is performed.

Signal combining system for constant envelope transmission of information

Methods and apparatus for generating composite code sequences are disclosed. An example method includes determining a first number of samples to be contributed into a first unit duration of a composite code sequence from respective component code sequences. The method also includes, based on the number of samples determined, randomly selecting samples from a plurality of samples of the respective ones of the component code sequences to enable the selected samples to more accurately represent the plurality of samples of the respective ones of the component code sequences. The method also includes compiling the selected samples into the first unit duration of the composite code sequence.

A method for time weighted combining of a plurality of binary phase shift key (BPSK) code sequences that is implemented by providing first, second and third sequences of chips of a BPSK code having a first, second and third code powers, respectively. A majority vote (MV) sequence of chips from the first, second and third sequences of chips is determined and a time multiplexed composite BPSK composite code sequence is formed by selecting a specific number of samples from each of the MV sequence of chips, and the two sequences of chips of the first, second and third sequences of chips that have the highest code powers, to form samples in a unit duration.

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Yorba Linda, CA, United States of America

Isaac M Jeng