MLC APSK Waveform for Phase Noise Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication systems face challenges in mitigating channel impairments such as phase noise and non-linear signal behavior, particularly at high frequency bands, where phase noise becomes a dominant impairment, leading to degraded signal quality and unequal error protection across bits in symbols.
Innovation Solution
Implementing multi-level coding (MLC) with amplitude phase shift keying (APSK) modulation, where a user equipment (UE) transmits a channel state information report to a base station to adaptively select waveform parameters, including modulation and coding schemes, to configure unequal error protection for different bits, using techniques like multi-stage decoding or parallel-independence decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional modulation schemes are used in high frequency bands, then communication can be established, but phase noise becomes a dominant impairment causing degraded signal quality and unequal error protection
Solution Approach 1:
The invention segments the coded bits into multiple groups, where each group is modulated onto a different constellation ring. This segmentation allows different error protection levels to be applied to different bit groups, with inner rings providing stronger protection against phase noise for critical bits and outer rings providing weaker protection for less critical bits, thereby resolving the contradiction between maintaining signal quality and dealing with phase noise impairment.
Solution Approach 2:
The invention applies local quality by providing unequal error protection to different groups of bits within the same modulation symbol. By assigning different coding rates and protection levels to different bit groups mapped to different rings, the system optimizes protection for phase noise affecting specific bit positions while maintaining overall communication efficiency, thus improving reliability without uniformly sacrificing performance across all bits.
2Reliability
If adaptive waveform selection is implemented to mitigate channel impairments, then communication reliability improves, but system complexity increases due to additional signaling and processing
Solution Approach 1:
The invention implements dynamic adaptive waveform selection where the UE evaluates channel conditions and dominant impairments, then dynamically selects from multiple MLC APSK waveform configurations with different ring structures, coding rates, and modulation orders. The base station receives feedback and adapts the waveform parameters in real-time, providing flexible adaptation to changing channel conditions while maintaining manageable complexity through standardized selection from predefined configurations.
Solution Approach 2:
The invention changes multiple waveform parameters simultaneously including modulation order, constellation ring configuration, coding rate, and error protection distribution. By coordinating changes across these parameters based on channel state information and dominant impairment identification, the system achieves improved communication reliability through adaptive optimization while controlling complexity through systematic parameter adjustment rather than complete waveform redesign.
3Reliability
If unequal error protection is applied to different bits, then phase noise mitigation improves, but modulation and coding complexity increases
Solution Approach 1:
The invention segments coded bits into multiple groups that are mapped to different constellation rings, with each segment receiving tailored error protection through different coding rates. This segmentation approach enables phase noise mitigation by providing stronger protection to critical bit segments while maintaining acceptable complexity through systematic grouping and standardized coding schemes applied to each segment.
Solution Approach 2:
The invention adds the dimension of multiple constellation rings to the traditional single-ring modulation, creating a multi-dimensional modulation space where different rings serve different error protection functions. This dimensional expansion allows unequal error protection to be implemented through the radial dimension (ring selection) rather than requiring complex temporal or spatial multiplexing, thereby improving phase noise mitigation while controlling modulation complexity through geometric organization.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described that support a single carrier multi-level coding (MLC) amplitude phase shift keying (APSK) modulated waveform. For example, a user equipment (UE) capable to communicate using MLC APSK modulated waveforms may transmit a channel state information (CSI) report, including a recommendation for a waveform configuration, to a base station. The base station may receive the CSI report and may transmit a configuration message to the UE, which may configure the UE with a set of waveform parameters associated with MLC APSK modulation. The UE may receive the configuration message and may communicate with the base station using MLC APSK modulated waveforms and based on the set of waveform parameters, which may reduce phase noise and provide lower peak average power ratio (PAPR) signaling.