LDPC Channel Encoding with Shortening and Puncturing Patterns
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Solution Overview
Problem
Existing communication systems face challenges in efficiently supporting various codeword lengths and code rates using Low-Density Parity Check (LDPC) codes due to the high memory requirements for storing different parity check matrices, which reduces system efficiency.
Innovation Solution
The method involves shortening or puncturing a given parity check matrix to generate LDPC codes with different codeword lengths and code rates, using a Bose-Chaudhuri-Hocquenghem (BCH) code for encoding and applying specific shortening or puncturing patterns to optimize performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different parity check matrices are stored to support various codeword lengths and code rates, then the system can support diverse coding requirements, but the memory requirements increase significantly
Solution Approach 1:
The patent applies universality by designing a single parity check matrix that can serve multiple functions by applying different shortening and puncturing patterns. Instead of storing separate matrices for each codeword length and code rate, one universal matrix is used to generate various LDPC codes through systematic modification patterns, thereby reducing memory requirements while maintaining support for diverse coding requirements
Solution Approach 2:
The patent employs parameter changes by modifying the structure of the parity check matrix through controlled shortening and puncturing operations. By changing parameters such as the number of shortened bits, number of punctured bits, and their positions, the system generates different effective code rates and codeword lengths from a single base matrix, avoiding the need to store multiple complete matrices
2Adaptability or versatility
If multiple parity check matrices are stored for different coding configurations, then various code rates can be supported, but system complexity increases
Solution Approach 1:
The system uses a universal parity check matrix that can be adapted to multiple code rates through standardized shortening and puncturing procedures. This universal approach reduces system complexity by eliminating the need to manage and switch between multiple separate matrices, while still providing flexible code rate support through controlled modifications
Solution Approach 2:
The patent segments the parity check matrix into functional regions (information bits, parity bits, shortened positions, punctured positions) that can be independently controlled. This segmentation allows systematic generation of different code rates by applying specific patterns to different segments, reducing the complexity of managing complete alternative matrices
3Quantity of substance
If shortening and puncturing operations are applied to a given parity check matrix, then memory requirements are reduced, but the encoding complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-defining standardized shortening and puncturing patterns that can be systematically applied to the parity check matrix. These predetermined patterns reduce encoding complexity by providing clear, repeatable procedures rather than requiring complex real-time decisions about which bits to shorten or puncture, while still achieving memory reduction through the use of a single base matrix
Data Source
AI summary
A method is provided for channel encoding in a communication system using an LDPC code. The method includes encoding input bits using a BCH code, shortening bits of the encoded input bits according to a number of bit groups to be shortened and an order among a plurality of orders according to which the bit groups are shortened, wherein the number of bit groups to be shortened is based on a number of bits to be shortened, which is based on a number of the encoded input bits, encoding information bits including the encoded input bits and the shortened one or more bits, using an LDPC code to generate parity bits, puncturing bits in the parity bits based on a puncturing parameter among puncturing parameters, and transmitting a signal generated from the encoded information bits based on the punctured bits. The plurality of orders being based on the puncturing parameters and including first and second orders.