QC-LDPC Parity Check Matrix for 3888-Bit 5/6 Wi-Fi Coding
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Solution Overview
Problem
Existing communication systems using LDPC codes face limitations in block length and code rate, particularly with the longest block length supported in 802.11 standards being 1944 bits, which restricts achievable gains in radio channels.
Innovation Solution
The implementation of a quasi-cyclic-low-density parity-check (QC-LDPC) code with a block length of 3888 bits and a code rate of 5/6, which allows for efficient encoding and decoding processes by utilizing a parity check matrix with a cyclic structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the block length is increased beyond 1944 bits to achieve higher coding gains, then the achievable gains in radio channels improve, but the device complexity and processing requirements increase
Solution Approach 1:
The 3888-bit block is divided into two separate 1944-bit blocks, each processed independently through the encoding function. This segmentation allows the system to achieve the coding gains of longer blocks while maintaining the processing complexity of shorter blocks, as each segment can be handled by existing hardware designed for 1944-bit blocks.
Solution Approach 2:
Two 1944-bit coded blocks are merged into a single 3888-bit transmitted block by concatenation. This merging achieves the effect of longer block processing for improved coding gain while using multiple instances of the same encoding function, thereby managing complexity through reuse of proven components.
2Reliability
If a QC-LDPC code with block length 3888 bits is implemented, then the coding gain and performance across modulation schemes improve, but the encoding and decoding processing time increases
Solution Approach 1:
The encoding process segments the 3888-bit block into two independent 1944-bit encoding operations. This allows parallel processing of segments and reuses the same encoding function multiple times, reducing the overall processing time compared to implementing a completely new 3888-bit encoding function from scratch.
Solution Approach 2:
The same encoding function designed for 1944-bit blocks is copied and applied twice to process the 3888-bit block. This copying approach leverages existing optimized code, ensuring consistent performance across modulation schemes while avoiding the need to develop and verify a new encoding function for the longer block length.
3Productivity
If the code rate is set to 5/6 with block length 3888 bits, then the data transmission efficiency improves, but the parity bit generation complexity increases
Solution Approach 1:
The parity bit generation process is segmented into two independent sets of parity bits, one for each 1944-bit segment. This segmentation allows the use of existing parity generation logic designed for 1944-bit blocks, maintaining manageable complexity while achieving the high code rate of 5/6 for improved transmission efficiency.
Solution Approach 2:
The parity bits from two separate 1944-bit encoding operations are merged into the final 3888-bit codeword. This merging approach achieves high transmission efficiency through the 5/6 code rate while keeping the complexity of parity generation manageable by reusing proven parity generation functions for each segment.
Data Source
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AI summary
In some implementations, an apparatus may include a transmitter and one or more processors. The one or more processors may be configured to identify, according to a code rate of 5/6 and a code block size of 3888 bits, a first binary parity check matrix for a quasi-cyclic-low-density parity-check (QC-LDPC) code. The first binary parity check matrix may correspond to a first exponent matrix having 96 values. The one or more processors may be configured to encode data using the first binary parity check matrix. The one or more processors may be configured to transmit the encoded data.