FEC Decoder Bypass for Power Reduction in Wireless Receivers

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Solution Overview

Problem

In broadband wireless networks, the inefficient operation of forward error correction (FEC) decoders in receivers leads to significant power consumption and reduced battery life in mobile wireless communications devices, especially in poor signal conditions.

Innovation Solution

A method and device that selectively disable or bypass the FEC decoder based on a reliability metric of the received radio frequency channel quality, using a reliability threshold to predict when FEC decoding is likely to fail, thereby conserving power and utilizing a Hybrid-ARQ unit to request retransmissions when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If FEC decoding is performed on all received code blocks, then decoding reliability is maintained, but power consumption increases significantly

Engineering Contradiction:
Improvedecoding reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by performing channel quality assessment and decoding probability prediction before initiating FEC decoding. The receiver evaluates channel conditions and predicts whether decoding is likely to succeed, then selectively enables or disables the FEC decoder based on this prediction. This prevents unnecessary decoding operations in poor channel conditions, significantly reducing power consumption while maintaining decoding reliability when conditions are favorable.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If FEC decoder operates in poor signal conditions, then decoding attempts are made, but decoding success probability is low and resources are wasted

Engineering Contradiction:
Improvedecoding efficiencyVSAvoiddecoding success probability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements dynamics by making the FEC decoder operation dynamic rather than static. The receiver continuously monitors channel quality metrics and adjusts the decoding operation state in real-time based on current conditions. When channel quality deteriorates below a threshold, the system dynamically switches from active decoding to a bypass state, adapting to changing signal conditions and avoiding inefficient resource utilization in poor signal environments.

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If FEC decoding is bypassed in poor channel conditions, then power consumption is reduced, but decoding reliability may be compromised

Engineering Contradiction:
Improvepower consumptionVSAvoiddecoding reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent employs feedback mechanisms where the receiver continuously monitors channel quality metrics and uses this information to control FEC decoder operation. The system measures channel conditions, compares them against thresholds, and provides feedback to the decoding control logic to adjust operation accordingly. This closed-loop approach ensures that decoding is performed only when channel conditions support successful decoding, maintaining reliability while minimizing power consumption.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2416515B1Forward error correction decoding avoidance based on predicted code block reliability
Publication Date: 2019.01.23 BLACKBERRY LTD
  • EP2416515B1 patent drawingFigure 1
  • EP2416515B1 patent drawingFigure 2
  • EP2416515B1 patent drawingFigure 3

AI summary

A method and device for performing forward error (FEC) correction avoidance based upon predicted block code reliability in a communications device is provided. An avoidance unit comprising a metric computation unit and a decision unit generates a reliability metric based upon a received code block. The reliability metric is compared to a reliability threshold, and the forward error correction decoder in the communications device is disabled if the metric is below or equal to the threshold.