Multi-level channel coding for wireless communications
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently utilizing higher-order modulation schemes due to unequal protection of bits, leading to unreliable least significant bit (LSB) log likelihood ratios (LLRs) in non-coherent transmission, which affects spectral efficiency and network resource utilization.
Innovation Solution
The implementation of multi-level channel coding, where bits are segmented into most significant bits (MSBs) and least significant bits (LSBs) and processed using different chains, with MSBs mapped to higher-order constellations formed from lower-order constellations, enhancing LSB LLR reliability and enabling higher modulation orders without performance degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher-order modulation schemes are used to improve spectral efficiency, then data transmission rate is improved, but bit protection reliability deteriorates due to unequal protection of MSBs and LSBs
Solution Approach 1:
The patent segments the bit stream into MSBs and LSBs, applying different processing chains to each. MSBs are processed with one coding/modulation path while LSBs are processed with a different path, allowing tailored protection strategies for each bit type to overcome the unequal protection problem in traditional higher-order modulation schemes
Solution Approach 2:
The patent applies different quality levels of protection to different parts of the data stream. MSBs receive one level of channel coding and modulation treatment, while LSBs receive a different level of treatment, optimizing overall system performance by matching protection quality to bit significance rather than treating all bits equally
2Productivity
If higher-order constellations are used to increase data rate, then spectral efficiency is improved, but LSB LLR reliability deteriorates in non-coherent transmission
Solution Approach 1:
The patent divides the modulation process into separate processing chains for MSBs and LSBs. LSBs are processed through a dedicated chain that generates more reliable LLRs, enabling higher-order constellations to be used in non-coherent transmission without sacrificing LSB decoding accuracy
Solution Approach 2:
The patent changes the processing parameters specifically for LSBs, applying different channel coding rates, modulation schemes, or LLR scaling factors to improve LSB LLR reliability. This allows the system to use higher-order modulations while maintaining adequate LSB protection through parameter optimization
3Reliability
If multi-level channel coding is implemented to improve LSB LLR reliability, then bit protection is improved, but system complexity increases due to multiple processing chains
Solution Approach 1:
While segmentation into multiple processing chains inherently increases complexity, the patent organizes these chains efficiently with shared components where possible, such as common modulation schemes or coding structures, to minimize the actual implementation complexity while maintaining the benefits of differentiated processing
Solution Approach 2:
The patent employs universal processing blocks that can handle both MSB and LSB processing with different parameters. By using multi-functional components that can be configured for different processing chains, the overall system complexity is reduced compared to having completely separate dedicated hardware for each chain
4Reliability
If different processing chains are used for MSBs and LSBs to enhance reliability, then bit-level performance is improved, but implementation complexity increases
Solution Approach 1:
The patent achieves different processing for MSBs and LSBs primarily through parameter changes rather than fundamentally different processing architectures. By using the same processing chain structure with different coding rates, modulation orders, or LLR scaling parameters, implementation becomes simpler while still achieving differentiated bit-level protection
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a transmitter device may segment a plurality of bits of a communication into a first set of bits and a second set of bits; process the first set of bits using a first processing chain and the second set of bits using a second processing chain, wherein the first set of bits is mapped to most significant bits (MSBs) of one or more symbols of a composite constellation and the second set of bits is mapped to least significant bits (LSBs) of the one or more symbols of the composite constellation, and wherein the composite constellation is formed from a plurality of lower order constellations; modulate the first set of bits and the second set of bits to generate a set of modulated symbols; and transmit the set of modulated symbols. Numerous other aspects are provided.