Non-binary LDPC Interleaver Mapping for QAM Decoding
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Solution Overview
Problem
In high-capacity communication systems using quadrature-amplitude modulation (QAM) with non-binary LDPC codes, the increased complexity of error correction and decoding performance varies with modulation order, necessitating improved methods for mapping codeword symbols to modulation symbols to enhance decoding performance.
Innovation Solution
A transmitter and signal processing method that interleaves non-binary symbols based on their error correction capabilities, mapping higher-order symbols to most significant symbols and lower-order symbols to least significant symbols in modulation symbols, thereby optimizing the placement of symbols in modulation symbols to reduce performance degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the modulation order of QAM is increased to achieve high frequency efficiency, then data transmission capacity is improved, but the complexity of non-binary LDPC encoding increases drastically
Solution Approach 1:
The patent changes the mapping relationship between codeword symbols and modulation symbols by introducing different mapping patterns (first mapping pattern and second mapping pattern) based on the modulation order. This allows the system to adapt to different complexity levels while maintaining high data transmission capacity, resolving the contradiction between productivity and device complexity.
2Reliability
If different variable nodes have different error correction capabilities, then decoding performance varies, but determining optimal mapping becomes more complex
Solution Approach 1:
The patent applies local quality by assigning different mapping patterns to different variable nodes based on their individual error correction capabilities. Variable nodes with higher error correction capabilities use one mapping pattern while those with lower capabilities use another, optimizing decoding performance for each node's specific characteristics without requiring complex centralized control.
Solution Approach 2:
The patent performs preliminary classification of variable nodes into different groups based on their error correction capabilities before the actual encoding process. This preliminary action allows the system to pre-determine which mapping pattern each variable node should use, simplifying the overall mapping determination process while maintaining optimal decoding performance.
Data Source
AI summary
A transmitter, a receiver and signal processing methods are provided. The transmitter includes: an encoder configured to perform encoding on an information word based on a parity check matrix to generate a codeword including a plurality of non-binary symbols; an interleaver configured to interleave the codeword; and as modulator configured to modulate the interleaved codeword to generate a plurality of modulation symbols. The interleaver is configured to interleave the codeword such that the modulator maps a predetermined non-binary symbol from among the plurality of non-binary symbols constituting the codeword to a predetermined position in a modulation symbol among the plurality of modulation symbols.