Variable Forward Error Correction Encoding for Packet Headers
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Solution Overview
Problem
Existing communication systems lack the ability to provide variable forward error correction (FEC) protection levels within data packets, particularly failing to offer enhanced protection for critical header data compared to other data, leading to inefficiencies in error correction and potential packet discarding due to single bit errors.
Innovation Solution
Implementing a system with a convolutional encoder that varies the code rate and repetition rate for different portions of the data packet, using a single interleaver and decoder, allowing for variable FEC protection across segments, thereby enhancing error correction and reducing the need for flush bits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate FEC processes are used for headers and data, then different protection levels can be provided, but system complexity increases and flush bits are required for each process
Solution Approach 1:
The patent segments the data stream into header portions and data portions, applying different FEC protection levels to each segment. The encoder varies the code rate and repetition rate specifically for header portions compared to data portions, allowing differentiated protection without requiring separate FEC processes. This resolves the contradiction by achieving segment-specific protection within a unified FEC framework.
Solution Approach 2:
The patent applies local quality by providing enhanced FEC protection specifically to header portions where reliability is critical, while using standard protection for data portions. The encoder selectively varies code rate and repetition rate based on the portion type (header vs. data), optimizing reliability where needed without unnecessarily increasing complexity across the entire system.
2Reliability
If multiple interleavers are used for different data portions, then variable protection levels are achieved, but device complexity and memory requirements increase
Solution Approach 1:
The patent employs a single interleaver that serves multiple functions: it interleaves both header and data portions, and works with variable code rates and repetition rates. This universal interleaver eliminates the need for separate interleavers for different data portions, reducing device complexity and memory requirements while maintaining the capability to provide variable protection levels through the encoder's selective parameter variation.
Solution Approach 2:
The patent merges the interleaving function into a single unified structure that handles all data portions (headers and data) rather than requiring separate interleavers. This consolidation reduces device complexity and eliminates the overhead of multiple interleaver structures while preserving the variable protection capability through the encoder's selective parameter application.
3Reliability
If higher FEC protection is applied to headers, then packet error rate decreases, but transmission efficiency decreases due to increased redundancy
Solution Approach 1:
The patent applies local quality by providing enhanced FEC protection (higher code rate variation and repetition rate) specifically to header portions where reliability is critical for packet processing, while using standard protection levels for data portions. This selective approach improves packet header reliability without unnecessarily sacrificing transmission efficiency across the entire packet, as only the header portion incurs the redundancy overhead.
Solution Approach 2:
The patent employs parameter changes by dynamically varying the code rate and repetition rate based on the data portion type. The encoder uses different parameter sets for headers (higher protection) versus data (standard protection), optimizing the balance between reliability and transmission efficiency. This parameter adaptation allows the system to achieve high header reliability while maintaining overall transmission efficiency.
Data Source
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AI summary
A communications system includes a transmitter having an encoder for encoding communications data and varying at least one of a puncturing of the code rate and a repetition rate on different portions of the communications data. As a result, a variable forward error correction is added to different portions of the communications data.