QC-LDPC Low-Rate Channel Coding for Low-SNR Long-Distance Links
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Solution Overview
Problem
Current channel coding technologies, such as those used in the 802.11n standard for WiFi, lack LDPC codes with low code rates like 1/6, 1/4, and 1/3, which are necessary for low signal-to-noise ratio and long-distance transmission environments.
Innovation Solution
The development of QC-LDPC codes with code rates of 1/6, 1/4, and 1/3, which can be multiplexed with existing codec structures, enabling their use in low signal-to-noise ratio and long-distance transmission scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing channel coding technologies (such as those in 802.11n standard) are used, then the system can maintain existing codec structures, but it cannot provide low code rate LDPC codes (1/6, 1/4, 1/3) necessary for low signal-to-noise ratio and long-distance transmission
Solution Approach 1:
The patent applies parameter changes by developing QC-LDPC codes with specific low code rates (1/6, 1/4, 1/3) that differ from existing code rates in the 802.11n standard. This involves changing the fundamental parameters of the LDPC code structure to achieve better performance in low signal-to-noise ratio environments while maintaining the QC-LDPC framework.
Solution Approach 2:
The patent segments the code rate space by introducing distinct low code rate options (1/6, 1/4, 1/3) separate from existing higher code rates. This segmentation allows the system to select appropriate code rates based on channel conditions, particularly for long-distance transmission where lower code rates provide necessary redundancy.
2Reliability
If new QC-LDPC codes with low code rates are developed, then transmission performance in low SNR environments is improved, but development cost and implementation complexity increase
Solution Approach 1:
The patent achieves universality by creating a family of QC-LDPC codes with different code rates (1/6, 1/4, 1/3) that all share the same underlying QC-LDPC structure. This multi-functional approach allows a single codec framework to handle multiple code rates, reducing overall system complexity compared to implementing separate coding schemes for different rate requirements.
Solution Approach 2:
The patent introduces dynamics by enabling the system to adaptively select among different code rates (1/6, 1/4, 1/3) based on channel conditions. This dynamic selection allows the codec to optimize between reliability and complexity by choosing appropriate code rates matching the transmission environment.
3Productivity
If higher code rates are used, then transmission speed is improved, but error correction capability in low signal-to-noise ratio environments deteriorates
Solution Approach 1:
The patent applies dynamics by enabling adaptive code rate selection among 1/6, 1/4, and 1/3 based on channel conditions. This allows the system to dynamically adjust between error correction capability and transmission speed by selecting the appropriate code rate for the current signal-to-noise ratio environment.
Solution Approach 2:
The patent uses parameter changes by varying the code rate parameter to balance transmission speed and error correction capability. Lower code rates (1/6, 1/4) provide better error correction for low SNR conditions, while the structured QC-LDPC design maintains reasonable transmission efficiency.
Data Source
AI summary
There are provided a channel coding method, a processing device, a communication method and a device. The channel coding method includes: using a generating matrix or a check matrix of QC-LDPC codes to channel-encode or channel-decode a code stream, wherein a code rate of the generating matrix or the check matrix is 1/4 or 1/3. The method can be used in a transmission environment with a low signal-noise ratio and a long distance.