LDPC Rate Matching with Circular Buffer and Systematic Bit Puncturing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rate matching methods for LDPC codes, such as those used in 802.11n, are inefficient and unclear in their implementation, particularly when shortening, puncturing, and repetition are applied to achieve specific code rates and block lengths, lacking a simple and effective method for modifying the code size (k, n) to (ktx, ntx).
Innovation Solution
The method involves generating a codeword vector using LDPC codes and performing circular buffer-based rate matching, which includes puncturing systematic bits, attaching dummy bits, and using redundancy versions to adjust the code size, allowing for flexible rate matching without the need for separate procedures for shortening, puncturing, and repetition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate procedures for shortening, puncturing, and repetition are used to achieve different code rates and block lengths, then flexibility in rate matching is improved, but device complexity and implementation difficulty increase
Solution Approach 1:
The patent combines shortening, puncturing, and repetition operations into a single integrated rate matching procedure. The encoder applies all three operations simultaneously through a unified process that modifies the codeword vector in one pass, eliminating the need for separate procedural steps and reducing implementation complexity while maintaining full flexibility in achieving different code rates and block lengths
Solution Approach 2:
The rate matching mechanism is designed as a universal procedure that can achieve multiple functions (shortening, puncturing, repetition) through a single integrated operation. The same encoder structure and algorithm handle all three operations regardless of the specific rate or block length target, making the system adaptable to different communication requirements without requiring separate specialized procedures
2Adaptability or versatility
If existing rate matching methods are implemented as described in 802.11n, then code rate adjustment is achieved, but clarity and efficiency of implementation deteriorate
Solution Approach 1:
The patent segments the rate matching process into clear, distinct operational phases: encoding the information bits to produce a codeword vector, applying the integrated rate matching operation (which internally handles shortening, puncturing, and repetition), and producing the final coded bits for transmission. This segmentation provides a clear implementation roadmap that improves ease of operation while maintaining code rate adjustment capability
Solution Approach 2:
The patent performs preliminary organization of the encoding and rate matching operations, establishing a clear procedural framework before actual implementation. The method defines upfront the relationship between information bits, codeword vector, and final coded bits, along with the integrated operations to be applied, making the implementation process clearer and more efficient
Data Source
AI summary
A method of producing a set of coded bits from a set of information bits for transmission between a first node and a second node in a wireless communications system, the method comprises generating a codeword vector by encoding the set of information bits with a low-density parity-check code, wherein the codeword vector is composed of systematic bits and parity bits. The method comprises performing circular buffer-based rate matching on the generated codeword vector to produce the coded bits for transmission, wherein the circular buffer-based rate matching comprises puncturing a first plurality of systematic bits.