DMRS Omission and Channel Estimation for Stable 5G NR Links
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Solution Overview
Problem
Existing 5G NR broadband cellular communication systems face reduced spectral efficiency, increased power consumption, and latency due to the mandatory use of demodulation reference signals (DMRS) even in stable channel conditions, particularly in Ultra-Reliable Low Latency Communications (URLLC) and Fixed Wireless Access (FWA) scenarios.
Innovation Solution
Implementing reduced pilot transmission and channel estimation techniques by omitting DMRS symbols in stable channel conditions, utilizing previous channel estimations and prediction methods to perform channel estimation, and updating channel models based on verified data and adjacent channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If demodulation reference signals (DMRS) are transmitted in every resource block, then channel estimation accuracy is maintained, but spectral efficiency is reduced
Solution Approach 1:
The patent extracts DMRS transmissions only from resource blocks where channel conditions warrant them. By selectively removing unnecessary DMRS transmissions in stable channel conditions, the system maintains channel estimation accuracy where needed while freeing up spectral resources for data transmission, thus resolving the contradiction between measurement precision and spectral efficiency
Solution Approach 2:
The patent implements dynamic DMRS transmission by allowing the presence or absence of DMRS to vary based on channel conditions. The system transitions from static mandatory DMRS transmission to dynamic selective transmission, adapting to channel stability characteristics and thereby optimizing both channel estimation accuracy and spectral efficiency
2Reliability
If demodulation reference signals (DMRS) are transmitted in every resource block, then channel estimation reliability is ensured, but power consumption increases
Solution Approach 1:
The patent extracts unnecessary DMRS transmissions from the communication system by identifying and removing them based on channel stability assessment. This selective removal reduces the energy required for signal transmission while preserving channel estimation reliability in conditions where DMRS are actually needed
Solution Approach 2:
The patent changes the transmission parameter of DMRS from a fixed mandatory state to a variable state based on channel conditions. By modifying this parameter dynamically, the system achieves reliable channel estimation only when necessary, thereby reducing overall power consumption
3Measurement precision
If demodulation reference signals (DMRS) are transmitted in every resource block, then channel estimation is continuously updated, but latency increases
Solution Approach 1:
The patent extracts redundant DMRS transmissions that occur in resource blocks with stable channel conditions. By removing these unnecessary transmissions, the system reduces the time required for signal processing and data transmission while maintaining adequate channel estimation freshness through selective DMRS placement
4Reliability
If demodulation reference signals (DMRS) are transmitted in every resource block, then channel variations are captured, but spectral resources are wasted
Solution Approach 1:
The patent extracts DMRS transmissions only from resource blocks where channel variations occur. By identifying stable versus varying channel conditions and removing DMRS from stable regions, the system maintains effective channel variation tracking where needed while maximizing spectral resource utilization in stable regions
Solution Approach 2:
The patent applies different transmission qualities to different resource blocks based on local channel conditions. Some resource blocks receive full DMRS protection while others operate with reduced or no DMRS, creating a non-uniform transmission strategy that optimizes both channel variation tracking and spectral efficiency
Data Source
AI summary
A system can, based on determining that a radio frequency channel of broadband cellular communications, facilitated by the system with at least one user equipment, satisfies a criterion with respect to a rate of change relative to a gap between demodulation reference signal transmissions, indicate, to the user equipment via a physical downlink control channel, to use a channel estimation with respect to a resource block that was made prior to transmitting the resource block, and transmit the resource block, wherein the resource block omits demodulation reference signal information.