Time-Varying DMRS Patterns for 5G NR Single Carrier Waveforms
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Solution Overview
Problem
Current wireless communication systems, particularly in 5G NR, face challenges in efficiently managing demodulation reference signals (DMRS) within single carrier waveforms, leading to suboptimal performance due to fixed DMRS configurations that do not adapt well to varying channel conditions, resulting in overhead inefficiencies and limited flexibility.
Innovation Solution
The implementation of a time-domain DMRS pattern that allows for varying DMRS locations and densities within single carrier waveforms, enabling dynamic resource allocation and improved multiplexing with other reference signals like PTRS, to enhance channel estimation and phase noise compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fixed DMRS configurations are used in single carrier waveforms, then device complexity is reduced and ease of operation is improved, but adaptability to varying channel conditions deteriorates and overhead efficiency worsens
Solution Approach 1:
The patent applies dynamics by transitioning from fixed DMRS configurations to time-varying DMRS patterns. The DMRS starting location and duration are dynamically adjusted based on channel conditions, allowing the system to adapt to varying multipath environments while maintaining manageable complexity through standardized adjustment rules.
Solution Approach 2:
The patent changes parameters by modifying DMRS configuration parameters (starting location, duration, density) based on channel conditions. Different time-domain patterns are selected from a predefined set, changing the temporal distribution of DMRS resources to optimize performance for different channel scenarios.
2Productivity
If fixed DMRS configurations are used, then device complexity is reduced, but overhead efficiency and spectral efficiency deteriorate
Solution Approach 1:
The patent enables dynamic resource allocation where DMRS density and positioning are adjusted over time based on channel variability. This dynamic approach optimizes spectral efficiency by allocating more DMRS resources when channel conditions require it and fewer resources when conditions are stable, improving overall productivity.
Solution Approach 2:
The patent implements periodic updates of DMRS patterns at different time scales (within slots and across slots), allowing the system to periodically adapt to changing channel conditions while maintaining structured resource allocation that avoids excessive complexity.
3Reliability
If time-varying DMRS patterns are implemented, then adaptability to channel conditions is improved, but device complexity and signal processing complexity increase
Solution Approach 1:
The patent achieves improved channel estimation accuracy through dynamic DMRS patterns that adapt to multipath channel characteristics. The time-varying starting locations and durations provide better temporal sampling of channel conditions, enhancing reliability of channel estimates while using predetermined patterns that limit processing complexity.
Solution Approach 2:
The patent uses predetermined DMRS patterns that can be copied and applied across different time instances and frequency resources. These standardized patterns reduce signal processing complexity by providing templates that receivers can efficiently correlate with, while still achieving adaptive performance through selective pattern application.
4Measurement precision
If DMRS resources are increased for better channel estimation, then measurement precision is improved, but overhead increases and spectral efficiency worsens
Solution Approach 1:
The patent applies local quality by concentrating DMRS resources in specific time-frequency regions where they are most needed based on channel conditions. Instead of uniformly increasing DMRS density everywhere, the system selectively places DMRS at varying starting locations and durations, achieving precise channel estimation where required while maintaining overhead efficiency in other regions.
Solution Approach 2:
The patent uses periodic DMRS patterns that cycle through different configurations, providing enhanced measurement precision at periodic intervals rather than continuously. This approach maintains good channel estimation accuracy while reducing average overhead compared to continuous high-density DMRS allocation.
Data Source
AI summary
Apparatus, methods, and computer-readable media for facilitating multiplexing of time-varying DMRS within a symbol are disclosed herein. An example method for wireless communication at a receiving device includes receiving a first symbol of a single carrier waveform, the first symbol including a first set of DMRS resources. The example method also includes receiving a second symbol of the single carrier waveform, the second symbol including a second set of DMRS resources, the second set of DMRS resources associated with at least one of a DMRS starting location and a DMRS duration that is different than the first set of DMRS resources.