Sparse Streaming Signal Reconstruction With Sliding Window Updates

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Solution Overview

Problem

Conventional methods for reconstructing sparse streaming signals face challenges such as significant artifacts at block boundaries, increased processing time, and uncertain processing delays, which are critical for real-time systems like video or audio data streams.

Innovation Solution

A real-time method using a sliding window approach for continuous data processing, where measurements are taken as a weighted moving average, and reconstruction is performed iteratively with a sliding snapshot of the system, ensuring guaranteed computational cost and avoiding block-based processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional blocking approach is used to process streaming signals, then finite-length reconstruction can be applied, but significant artifacts are introduced at block boundaries

Engineering Contradiction:
Improveapplicability of finite-length reconstruction methodVSAvoidsignal reconstruction quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent implements a sliding window approach where the measurement window continuously moves across the streaming signal, maintaining overlap between consecutive processing segments. This continuity eliminates the discrete block boundaries that cause artifacts, allowing the reconstruction algorithm to operate on continuous overlapping segments rather than separate blocks, thereby preserving signal quality at transition points.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent introduces dynamic adjustment of the sliding window parameters, including window size, step size, and overlap ratio, to optimize reconstruction quality for different signal characteristics. The measurement matrix and reconstruction algorithm adapt dynamically as the window slides through the signal, allowing the system to maintain high quality reconstruction across varying signal conditions without the rigid block structure limitations.

Inventive Principle:
Principle #15Dynamics

2Length of stationary object

If signal length increases for streaming signals, then more complete signal representation is achieved, but execution time and processing requirements increase significantly

Engineering Contradiction:
Improvesignal processing window sizeVSAvoidprocessing time
Core Design Contradiction:
Length of stationary objectVSLoss of time

Solution Approach 1:

The patent divides the streaming signal into overlapping segments using a sliding window of fixed size, processing each segment independently through the compressive sensing reconstruction algorithm. This segmentation allows the system to maintain a manageable processing window size while still capturing sufficient signal context, avoiding the need to process entire long-duration signals at once and thereby controlling execution time and computational requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sliding window approach processes only a partial portion of the total signal at any given time, advancing through the signal in incremental steps. This partial processing strategy enables real-time or near-real-time reconstruction by handling manageable chunks of data sequentially, rather than requiring all signal data to be processed simultaneously, thus significantly reducing processing time and computational resource requirements.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If conventional CS hardware and acquisition techniques are used, then sparse signals can be acquired at lower rates, but processing delay requirements cannot be guaranteed

Engineering Contradiction:
Improvesampling rate reductionVSAvoidprocessing delay guarantee
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The sliding window reconstruction algorithm maintains a running estimate of the signal as it processes each new segment, progressively refining the reconstruction rather than waiting until the end of signal acquisition. This preliminary reconstruction approach provides intermediate results at each window position, enabling the system to meet deterministic processing delay requirements by delivering partial reconstructions at predictable time intervals while still benefiting from compressive sampling rate reduction.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS8204718B2Method for reconstructing sparse streaming signals using greedy search
Publication Date: 2012.06.19 MITSUBISHI ELECTRIC RESEARCH LABORATORIES INC
  • US8204718B2 patent drawing
  • US8204718B2 patent drawing
  • US8204718B2 patent drawing

AI summary

A method reconstructs a streaming signal xn from streaming measurements by maintaining a working set of measurements, a working snapshot of the measurement system, an internal working signal estimate, and an external working signal estimate. Using a current working set of measurements, the internal working signal estimates, the working snapshot of the measurement system, and a model of a signal sparsity are refined. The external working signal estimate is refreshed. A subset of coefficients of the external working signal estimate is committed to an output. A next streaming measurement and a corresponding next measurement vector are received. The working set of measurements, the working snapshot of the measurement system, and the internal working signal estimate are updated to incorporate the next measurement and the corresponding measurement vector. Then, an oldest measurement and a corresponding oldest measurement vector, and an effect of the committed subset of coefficients are removed.