Multi-Layer FEC Parity Coding for Low-Latency HARQ Reliability
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Solution Overview
Problem
Current wireless communication systems face challenges in meeting the demands of future applications requiring high throughput, low latency, and high reliability due to insufficient error-detection capabilities and inflexible HARQ operations, especially in noisy channels and varying device computational power.
Innovation Solution
Implementing multi-layer packet coding (MLPC) that segments data into multiple layers of FEC codewords and parity codewords, using XOR operations to generate additional parity codewords, and employing HARQ processes for retransmission based on feedback, to enhance error detection and reduce latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multi-layer packet coding with multiple XOR operations is implemented, then error detection capability is improved, but device complexity increases
Solution Approach 1:
The data stream is segmented into multiple data segments that are encoded into separate FEC codewords, which are then organized into multiple layers. Each layer undergoes independent XOR operations to generate parity codewords. This segmentation allows the system to improve error detection capability through multiple layers while managing complexity by processing each layer independently rather than as a monolithic structure.
Solution Approach 2:
The patent extends the traditional single-layer FEC structure into multiple dimensions by creating a multi-layer hierarchy. Instead of a single XOR operation on one set of codewords, the system performs XOR operations across multiple layers (first layer parity from FEC codewords, second layer parity from first layer parity codewords). This dimensional expansion improves error detection capability by providing multiple layers of redundancy while organizing complexity into a structured multi-dimensional framework.
2Reliability
If traditional HARQ retransmission is used, then reliability is improved, but transmission latency increases
Solution Approach 1:
The system performs preliminary error detection and correction by generating multiple layers of parity codewords before transmission. The receiver can attempt to decode and correct errors using these pre-generated parity codewords before requesting retransmission. This preliminary action reduces the need for full HARQ retransmission cycles, thereby improving reliability while reducing the time loss associated with repeated retransmissions.
Solution Approach 2:
The patent implements a feedback mechanism where the receiver sends acknowledgments (ACK/NACK) based on successful decoding of FEC codewords. When errors are detected, the system triggers selective retransmission of only the affected data segments rather than entire transport blocks. This feedback-driven selective retransmission improves reliability by ensuring error-free delivery while reducing latency by avoiding unnecessary retransmission of correctly received data.
3Productivity
If selective retransmission of FEC codewords is implemented, then productivity is improved, but device complexity increases
Solution Approach 1:
The transport block is divided into multiple independently encodable data segments, each generating separate FEC codewords. This segmentation enables the receiver to identify and request retransmission of only specific failed FEC codewords rather than requiring retransmission of entire transport blocks or sections. The segmentation improves productivity by reducing redundant transmissions while managing complexity through modular, independent processing of each segment.
Solution Approach 2:
The HARQ process is made dynamic by allowing selective retransmission based on real-time feedback about which specific FEC codewords failed decoding. Rather than following a fixed retransmission pattern, the system adapts by retransmitting only the necessary codewords identified through feedback bits. This dynamic approach improves transmission efficiency by optimizing retransmission resources while the structured feedback mechanism keeps complexity manageable through clear, segment-specific control signals.
Data Source
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AI summary
Communication devices, systems and methods for performing multi-layer packet coding (MLPC) in a wireless system are provided. The MLPC includes segmenting a data stream into a plurality of data segments, encoding each of the plurality of data segments into a plurality of forward error correction (FEC) codewords, performing a first exclusive OR (XOR) operation on the plurality of FEC codewords to generate a plurality of first layer parity codewords, performing a second XOR operation on the plurality of first layer parity codewords to generate at least one second layer parity codeword, and transmitting at least one of: the plurality of FEC codewords, the plurality of first layer parity codewords, or the at least one second layer parity codeword.