Lifted LDPC Code Description for Low-Overhead Wireless Encoding
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently encoding and decoding data at high rates while maintaining practical implementation costs, particularly in next-generation technologies like NR, due to the complexity of low-density parity-check (LDPC) codes.
Innovation Solution
The method involves compactly describing LDPC codes by using a single base parity check matrix for a set of lifting sizes, allowing generation of multiple codes through operations like floor or modulo, and applying lifting values to interconnect edges in base parity check matrices to create lifted LDPC codes for encoding and decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If conventional methods are used to describe lifted LDPC codes, then code generation flexibility is maintained, but signaling overhead increases and processing efficiency decreases
Solution Approach 1:
The patent uses a base parity check matrix as a template that is copied and lifted multiple times to generate different lifted LDPC codes. Instead of signaling the entire lifted code structure, only the base matrix and lifting parameters are signaled, significantly reducing overhead while maintaining the ability to generate various code rates and lengths through systematic copying and parameter variation.
Solution Approach 2:
The patent employs parameter-based code generation where lifting size, base matrix selection, and connection patterns are controlled by signaled parameters rather than explicit code descriptions. By changing these parameters, the system can efficiently generate different lifted LDPC codes adapted to various channel conditions and performance requirements without increasing signaling overhead.
2Manufacturing precision
If detailed code description is provided for each lifted LDPC code, then code generation accuracy is ensured, but device complexity and processing overhead increase
Solution Approach 1:
The patent segments the lifted LDPC code description into a compact base parity check matrix and separate lifting parameters. This segmentation allows the system to maintain precise code generation through the base matrix structure while reducing overall complexity by separating the static base definition from the dynamic lifting parameters that can be efficiently signaled and processed.
3Adaptability or versatility
If multiple lifted LDPC codes are supported with different lifting sizes, then code adaptability improves, but signaling overhead and processing complexity increase
Solution Approach 1:
The patent creates a universal base parity check matrix that can serve as the foundation for multiple lifted LDPC codes with different lifting sizes and code rates. This universal base matrix enables the system to support diverse coding requirements through parameter variation alone, maintaining high adaptability while avoiding the need to signal separate code structures for each lifting configuration.
Data Source
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AI summary
Certain aspects of the present disclosure generally relate to techniques for compactly describing lifted low-density parity-check (LDPC) codes. A method for wireless communications by a transmitting device generally includes selecting a first lifting size value Z and a first set of lifting values; generating a first lifted LDPC code by applying the first set of lifting values to interconnect edges in copies of a base parity check matrix (PCM) to obtain a first lifted PCM corresponding to the first lifted LDPC code; determining a second set of lifting values for generating second lifted PCM corresponding to a second lifted LDPC code for a second lifting size value based on the first set of lifting values; encoding a set of information bits based on at least one of: the first lifted LDPC code or the second lifted LDPC code to produce a code word; and transmitting the code word.