Rate-1/4 LDPC Coding Scheme for Low-SNR Wireless Transmission
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Solution Overview
Problem
Existing information transmission systems using Low Density Parity Check (LDPC) codes face challenges in securing excellent communication quality, particularly in wireless communication systems where interference and low signal-to-noise ratios are prevalent.
Innovation Solution
The implementation of a new communication scheme that employs LDPC codes with a code length of 736 bits and a code rate of 1/4, combined with frequency hopping and error correction techniques, to improve signal reliability and reduce interference in wireless systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LDPC codes with conventional parameters are used, then error correction ability is provided, but communication quality deteriorates in low signal-to-noise ratio environments
Solution Approach 1:
The patent applies parameter changes by optimizing the LDPC code parameters specifically for rate 1/4 with code length 736. The parity check matrix is designed with specific row weights (3, 4, or 5) and column weights (3, 4, or 5) to improve decoding performance in low signal-to-noise ratio environments. This parameter optimization resolves the contradiction by tailoring the code parameters to the specific communication conditions.
2Reliability
If longer code length is used to improve error correction, then block error probability decreases, but transmission time increases
Solution Approach 1:
The patent resolves this contradiction by selecting an optimized code length of 736 bits for rate 1/4 LDPC codes. This specific parameter choice provides excellent error correction performance while maintaining reasonable transmission time. The parity check matrix is constructed with dimensions that balance error correction capability with decoding complexity and time requirements.
3Productivity
If higher code rate is used to increase data transmission speed, then productivity improves, but error correction ability deteriorates
Solution Approach 1:
The patent addresses this contradiction by optimizing the code rate parameter to 1/4, which provides a balanced trade-off between transmission speed and error correction capability. The parity check matrix is designed with specific density and structure that enable effective error correction even at this relatively low code rate, while still maintaining practical transmission speeds for the application.
Data Source
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AI summary
This technique relates to a transmitting apparatus and a transmission method, a receiving apparatus and a reception method, and programs that each enable securing of excellent communication quality in information transmission using an LDPC code. LDPC coding is executed using a check matrix of an LDPC code whose code length is 736 bits and whose code rate is 1/4, and modulation is executed using a repetition unit that has an LDPC code obtained by the LDPC coding, repeatedly arranged therein. The LDPC code includes information bits and parity bits, the check matrix includes an information matrix portion corresponding to the information bits and a parity matrix portion corresponding to the parity bits, the parity matrix portion has a stepwise structure, the information matrix portion is indicated by a check matrix initial value table, and the check matrix initial value table is a predetermined table indicating positions of elements of "1" of the information matrix portion for each eight columns. This technique is applicable to, for example, information transmission using the LDPC code.