Periodic Timing Reference Detection Using Recursive Integration

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Solution Overview

Problem

Current methods for detecting periodic timing references in signals, such as those used in LTE cell search, often result in false positives due to noise spikes, which can degrade detection sensitivity and accuracy.

Innovation Solution

An apparatus and method that utilize a correlator and integrator configured to correlate and accumulate signals with delayed versions, using integer multiples of the periodic timing reference's period, to distinguish between actual periodic timing references and noise spikes by analyzing the peak profile of the accumulated signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If recursive integration of correlation powers is performed for one slot duration, then detection sensitivity is improved, but false positives due to noise spikes increase

Engineering Contradiction:
Improvedetection sensitivityVSAvoidfalse positive rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The integration period is segmented into multiple slots rather than integrating over a single slot. The detector performs recursive integration across multiple slot durations, allowing it to distinguish true periodic signals (which appear in consistent positions across slots) from random noise spikes (which do not repeat periodically). This segmentation approach resolves the contradiction by improving detection sensitivity through extended integration while maintaining reliability through periodicity verification.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detector uses feedback by comparing correlation results from previous slots with current slot results. The recursive integration mechanism feeds back accumulated correlation values across multiple slots, and the system verifies whether detected peaks maintain consistent time offsets across slots. This feedback loop enables the system to confirm true periodic timing references while rejecting false noise-induced detections, thereby improving both sensitivity and reliability.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If integration time is extended to improve signal resolution, then detection accuracy improves, but power consumption increases

Engineering Contradiction:
Improvesignal resolutionVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The detector performs integration over multiple slots (excessive action beyond a single slot), but only processes and compares results at specific periodic intervals corresponding to the expected timing reference period. This partial processing approach allows the system to extend integration time for improved signal resolution while avoiding continuous processing that would excessively increase power consumption. The system selectively accumulates data over extended periods but only performs full analysis at relevant periodic points.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2728789B1Detecting a periodic timing reference in a received signal
Publication Date: 2019.09.18 BLACKBERRY LTD
  • EP2728789B1 patent drawingFigure 1
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  • EP2728789B1 patent drawingFigure 3

AI summary

An apparatus for detecting a periodic timing reference in a received signal comprises a correlator and an integrator. The correlator is configured to correlate the received signal with a template to produce a correlated signal indicating the presence of the periodic timing reference in the received signal. The integrator is configured to produce an accumulated signal by overlaying one or more delayed versions of the accumulated signal onto the correlated signal, and is further configured to delay the accumulated signals by integer multiples L of a period of the periodic timing reference, the integer multiples L being at least two.