Ranging Signals Using Kernel-Spreading Convolution for Silo SNR

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Solution Overview

Problem

In acoustic range and direction finding applications, particularly in silo measurements, there is a need for signals with enhanced signal-to-noise ratio (SNR) due to varying distances and complex silo geometries, as well as challenges from multi-path phenomena and noise, which complicates pulse discrimination and requires short, band-limited pulses to avoid interference.

Innovation Solution

A transmitter generates pulses by convolving a kernel with a spreading sequence, where the bit length and sparsity parameters form an ordered set with specific conditions, allowing for efficient pulse shaping and processing to enhance SNR and reduce interference, and a receiver deconvolves the spreading sequence to compress pulses and improve resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transmitted pulse length is increased to improve SNR, then the signal-to-noise ratio is enhanced, but the pulse interference increases and time resolution deteriorates

Engineering Contradiction:

Improvesignal-to-noise ratioVSAvoidtime resolution

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The transmitted pulse is segmented into multiple components through convolution of a kernel with a spreading sequence. The spreading sequence divides the pulse energy across multiple time samples, creating a structured waveform that can be later compressed at the receiver to achieve both high SNR and fine time resolution simultaneously

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The pulse structure employs nested parameters where the spreading sequence is convolved with the kernel, creating a hierarchical signal structure. The spreading sequence parameters (spreading length and sparsity) are nested within the overall pulse design, allowing the receiver to deconvolve and compress the signal to recover both energy and resolution

Inventive Principle:

Principle #7Nested doll (Nesting)

2Measurement precision

If the transmitted pulse length is decreased to improve time resolution, then the pulse separation is improved, but the signal-to-noise ratio deteriorates

Engineering Contradiction:

Improvetime resolutionVSAvoidsignal-to-noise ratio

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The invention changes the parameters of the spreading sequence (spreading length and sparsity) to independently control pulse duration and energy distribution. By adjusting these parameters, the system achieves short effective pulse length for time resolution while maintaining sufficient energy through optimized sparsity patterns for SNR

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If the signal bandwidth is increased to improve resolution, then the time and direction resolution are enhanced, but the signal becomes more susceptible to noise and interference

Engineering Contradiction:

ImproveresolutionVSAvoidnoise susceptibility

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The spreading sequence introduces periodic structure into the signal through its defined pattern of non-zero elements. This periodicity allows the receiver to use matched filtering and deconvolution techniques that enhance the desired signal while suppressing random noise and interference, achieving high resolution without increased noise susceptibility

Inventive Principle:

Principle #19Periodic action

4Adaptability or versatility

If the pulse length is extended to cover varying distances, then the adaptability to different ranges is improved, but the multi-path interference increases

Engineering Contradiction:

Improverange adaptabilityVSAvoidmulti-path interference

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The system dynamically adapts to varying distances by using the structured spreading sequence that can be processed through deconvolution. The spreading sequence parameters can be adjusted to match the expected range, and the dynamic deconvolution process at the receiver separates direct paths from multi-path reflections, maintaining adaptability while reducing interference

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8391336B2Variable length ranging and direction-finding signals constructed from bandlimited kernels and sparse spreading sequences

Publication Date: 2013.03.05 ROSEMOUNT TANK RADAR

AI summary

To generate a pulse for ranging, a kernel is convolved with a spreading sequence. The spreading sequence is parametrized by one or more ordered (length, sparsity) pairs, such that the first sparsity differs from the bit length of the kernel and/or a subsequent sparsity differs from the product of the immediately preceding length and the immediately preceding sparsity. Alternatively, a kernel is convolved with an ordered plurality of spreading sequences, all but the first of which may be non-binary. The pulse is launched towards a target. The reflection from the target is transformed to a received reflection, compressed by deconvolution of the spreading sequence, and post-processed to provide a range to the target and/or a direction of arrival from the target.