RC-LDPC Parity Check Matrix for Multi-Rate Error Correction
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Solution Overview
Problem
Current rate-compatible low density parity check (RC-LDPC) codes in communication systems suffer from performance degradation across various code rates, affecting overall system performance and stability, particularly in link adaptation and incremental redundancy-hybrid automatic retransmission request (IR-HARQ) schemes.
Innovation Solution
The proposed solution involves designing an RC-LDPC code structure with a parity check matrix that concatenates LDPC codes using both greedy and direct schemes, optimizing error correction performance across different code rates by incorporating sub-matrices that enhance link adaptation and IR-HARQ efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If simple puncturing operation is performed to adjust code rate, then code rate flexibility is improved, but error correction performance deteriorates
Solution Approach 1:
The parity check matrix is segmented into multiple sub-matrices (first sub-matrix, second sub-matrix, third sub-matrix) where each sub-matrix corresponds to a specific code rate. This segmentation allows the system to select the appropriate sub-matrix for the desired code rate, avoiding the performance degradation associated with simple puncturing while maintaining code rate flexibility.
Solution Approach 2:
The invention changes the structure of the parity check matrix by incorporating multiple sub-matrices with different configurations. Each sub-matrix is designed with specific properties optimized for its corresponding code rate, allowing the system to change parameters (sub-matrix selection) to achieve both code rate flexibility and maintained error correction performance.
2Reliability
If RC-LDPC code structure is optimized for specific code rates, then error correction performance is improved, but system adaptability to various code rates deteriorates
Solution Approach 1:
The parity check matrix is designed with a universal structure that can support multiple code rates through the inclusion of multiple sub-matrices. The first sub-matrix can be used for a first code rate, the second sub-matrix for a second code rate, and the third sub-matrix for a third code rate, allowing a single RC-LDPC code structure to universally support various code rates while maintaining optimized error correction performance for each.
3Reliability
If multiple separate LDPC codes are designed for different code rates, then error correction performance for each code rate is improved, but system complexity increases
Solution Approach 1:
Multiple LDPC codes designed for different code rates are merged into a single RC-LDPC code structure. The parity check matrix combines the first sub-matrix, second sub-matrix, and third sub-matrix, each optimized for specific code rates, into one unified structure. This merging allows the system to maintain the error correction performance benefits of multiple specialized codes while reducing system complexity by using a single code structure.
Data Source
AI summary
The present disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-generation (4G) communication system such as a long term evolution (LTE). A method and apparatus for transmitting a signal in a transmitting apparatus in a communication system supporting a rate compatible-low density parity check (RC-LDPC) code are provided. The method includes encoding information bits based on a first parity check matrix and a first code rate to generate a codeword, processing the codeword to generate a transmission signal, and transmitting the transmission signal.