LDPC Encoding Rate Adaptation With Reduced Table Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current WLAN encoding technologies face challenges in efficiently supporting higher encoding rates without incurring significant storage overheads, particularly in transitioning from low to high encoding rates in LDPC encoding processes.
Innovation Solution
An encoding method that determines a second codeword number and length based on first available bits and a correspondence established at a lower encoding rate, allowing the encoding apparatus to avoid storing separate correlations for high encoding rates, thereby reducing storage requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an encoder supporting a relatively low encoding rate is used for encoding, then a relatively high encoding rate may be implemented by puncturing more parity bits, but the encoding apparatus needs to store correspondence between available bits, codeword number, and codeword length at multiple encoding rates, increasing storage overheads
Solution Approach 1:
The encoding apparatus uses a single encoder designed for a lower encoding rate (e.g., 1/2) to perform encoding at multiple encoding rates (1/2, 2/3, 3/4, 5/6) by selectively puncturing parity bits. This universal encoder eliminates the need to store separate correspondence tables for each encoding rate, reducing storage overhead while maintaining adaptability across different encoding rates.
Solution Approach 2:
The system changes the effective encoding rate by varying the puncturing pattern of parity bits rather than changing the encoder itself. By adjusting which parity bits are punctured and how many are punctured, the same encoder can operate at different encoding rates, and the correspondence stored is only for the base encoding rate, not for each possible rate.
2Reliability
If separate encoders are used for different encoding rates, then encoding performance is optimized for each rate, but device complexity increases
Solution Approach 1:
Instead of having separate encoders for each encoding rate, the system employs a single universal encoder that can operate at multiple encoding rates through selective puncturing. This reduces device complexity by eliminating redundant encoder structures while maintaining optimized encoding performance through the use of a well-designed base encoder (e.g., 1/2 rate encoder) that serves multiple purposes.
3Productivity
If puncturing is used to achieve higher encoding rates, then transmission efficiency is improved, but the accuracy of determining codeword number and length becomes more difficult
Solution Approach 1:
The system pre-calculates and stores the correspondence between available bits, codeword number, and codeword length for the base encoding rate before transmission. This preliminary preparation allows the receiving end to accurately determine codeword parameters even when puncturing is applied, because the base correspondence is known and can be used to infer the punctured parameters through the known puncturing pattern.
Data Source
AI summary
Embodiments of this application disclose an encoding method, a decoding method, and a related apparatus, which may be applied to a wireless local area network system. An encoding apparatus determines first available bits based on to-be-encoded data bits and a first encoding rate, and determines a second codeword number and a second codeword length based on the first available bits and a correspondence between the first available bits, a first codeword number, and a first codeword length at the first encoding rate. The second codeword number is obtained based on the first codeword number, and the second codeword length is obtained based on the first codeword length. The encoding apparatus does not need to store a correspondence between available bits, a codeword number, and a codeword length at a second encoding rate, thereby reducing storage overheads of the encoding apparatus.