Multi-Element Modulation Mapping for Fading-Channel Reliability
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Solution Overview
Problem
Conventional communication systems face issues with low reliability due to deep attenuation and reliability unbalance of constellation points in modulation mapping, leading to poor anti-interference capabilities and high error rates, especially in fading channels.
Innovation Solution
A multi-element code modulation mapping method that divides a sequence of codes into groups, maps each group to multiple modulation symbols, and cascades them to improve reliability by distributing bits across different constellation points with varying reliability, utilizing techniques like direct total mapping, I/Q path mapping, and interleaving to enhance transmission performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional modulation mapping is used, then data transmission rate can be increased through high-order modulation, but reliability deteriorates due to deep attenuation and constellation point reliability unbalance
Solution Approach 1:
The code sequence is divided into multiple code groups, where each group is mapped to different modulation symbols. This segmentation allows different reliability levels to be assigned to different code groups, with more reliable modulation symbols carrying critical information and less reliable ones carrying less critical information, thus resolving the contradiction between high transmission rate and reliability.
Solution Approach 2:
Different code groups are assigned to different constellation points with varying reliability characteristics. The mapping process ensures that codes requiring higher reliability are mapped to constellation points with better anti-interference capability, while codes with lower reliability requirements are mapped to points with poorer characteristics. This local quality differentiation maintains high overall transmission rate while ensuring critical data reliability.
2Productivity
If all modulation symbols are mapped to low-reliability constellation positions, then modulation capacity is maximized, but anti-interference capability deteriorates
Solution Approach 1:
The mapping process assigns different code groups to different constellation points based on their reliability characteristics. Constellation points with better anti-interference capability (higher reliability) are used for mapping code groups that require higher reliability, while points with poorer characteristics are used for code groups with lower reliability requirements. This local quality differentiation ensures that modulation capacity is maximized while maintaining adequate anti-interference capability for critical information.
3Productivity
If multi-element error correcting code is combined with high-order modulation, then data transmission rate increases, but decoding reliability deteriorates under deep attenuation
Solution Approach 1:
The coded sequence is divided into multiple code groups that are separately mapped to different modulation symbols. This segmentation works in conjunction with multi-element error correcting codes to provide layered protection: the error correcting code handles random errors while the differential mapping handles deep attenuation effects. Critical code groups are mapped to more reliable symbols, ensuring decoding reliability even under deep attenuation conditions while maintaining high transmission rate.
Data Source
AI summary
Disclosed is a multi-element code modulation mapping method and device, relating to communications and designed to improve communication reliability. The method includes that: multi-element domain coding is performed on a first sequence including K multi-element codes to obtain a second sequence including N multi-element codes; K1 and K2 are calculated according to a multi-element domain element number q and a modulation order M, wherein K1*log2 q=K2*log2 M, both K1 and K2 are integers not smaller than 2, and both q and M are power of 2; the second sequence is divided into z groups of multi-element codes with each group including K1 multi-element codes, wherein C=formula (I), and formula (II) represents rounding up; each group of multi-element codes is mapped to a constellation diagram to form K2 Mth-order modulation symbols; and z groups of Mth-order modulation symbols are sequentially cascaded to form a modulation symbol to be sent. The present disclosure further discloses a computer storage medium.