Polar SCL Decoding With Dynamic List Size Reduction
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Solution Overview
Problem
Current wireless communication systems face challenges in balancing decoding reliability and latency during polar decoding, as maintaining a large list size improves reliability but increases latency, while a smaller list size reduces latency but may decrease decoding accuracy.
Innovation Solution
A user equipment (UE) initiates successive cancellation list (SCL) decoding and dynamically adjusts the list size based on path metrics, reducing the list size when specific threshold conditions are met, such as a relationship between the first and second path metrics, to maintain accuracy while reducing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large list size is maintained during SCL decoding, then decoding reliability is improved, but latency increases
Solution Approach 1:
The patent implements dynamic list size adjustment during SCL decoding by monitoring path metric relationships between candidate paths. The list size is adaptively changed based on real-time decoding conditions, allowing the system to maintain high reliability when needed while reducing latency when the channel conditions permit smaller list sizes.
Solution Approach 2:
The patent changes the list size parameter during decoding based on path metric comparisons. When the difference between the best and second-best path metrics exceeds a threshold, the list size is reduced, thereby decreasing latency while maintaining decoding performance when the metric gap indicates sufficient confidence in the current best path.
2Loss of time
If a small list size is used during SCL decoding, then latency is reduced, but decoding accuracy decreases
Solution Approach 1:
The patent employs feedback mechanisms by continuously monitoring path metric relationships during decoding. The system uses the relationship between path metrics as feedback to dynamically adjust list size, ensuring that accuracy is maintained when path metrics indicate uncertainty while allowing latency reduction when metrics show clear differentiation between candidate paths.
Solution Approach 2:
The decoding system performs self-adjustment of list size based on its own internal path metric evaluations. The SCL decoder autonomously determines when to reduce list size by comparing path metrics without external intervention, enabling it to self-optimize between accuracy and latency based on the current decoding state.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. The user equipment (UE) may initiate a successive cancellation list (SCL) decoding procedure, and may perform the SCL decoding procedure across various nodes (e.g., for each information bit through a decoding tree). At each node, the UE may determine whether a relationship between a first path metric and a second path metric satisfy a threshold. In some examples, the UE may determine whether multiple thresholds are satisfied. If conditions are satisfied (e.g., the relationship between the two path metrics satisfies a threshold), then the UE may decrease a list size of the SCL decoding.