Common Reference Signal Phase Discontinuity Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication systems face issues with reduced common reference signal (CRS) periodicity, leading to phase discontinuity between CRS transmissions, which results in received signal nulls and CRS coverage holes, especially with high mobility user equipment and New Carrier Type (NCT) systems.
Innovation Solution
Introducing phase discontinuity between CRS transmissions on different subframes and extending CRS sequence periodicity to increase the number of sequences transmitted, with indicators sent from base stations to user equipment (UEs) to manage phase continuity, allowing coherent combining across subframes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If reduced CRS periodicity is utilized, then CRS overhead is reduced, but phase discontinuity occurs between CRS transmissions causing received signal nulls and coverage holes
Solution Approach 1:
The patent dynamically adjusts the CRS sequence periodicity based on system configuration and mobility conditions. By making the periodicity configurable rather than fixed, the system can adapt to different scenarios - using extended periodicity when phase discontinuity causes problems, and standard periodicity when overhead reduction is prioritized, thus resolving the contradiction between reducing overhead and maintaining coverage reliability
Solution Approach 2:
The patent changes the temporal parameter of CRS sequence periodicity from a fixed value to an extended configurable period. This parameter change allows the system to maintain more distinct CRS sequences over time, preventing the phase discontinuity issues that arise with reduced periodicity while still controlling overhead through selective application
2Quantity of substance
If extended CRS sequence periodicity is used, then number of CRS sequences is increased, but system complexity increases
Solution Approach 1:
The patent segments the CRS transmission into multiple sequences distributed over an extended periodicity period. Instead of transmitting all sequences frequently, they are spread out over a longer time period, which increases the number of available sequences for measurement while reducing the instantaneous processing complexity and allowing UEs to process sequences as they arrive over time
3Measurement precision
If phase discontinuity is introduced between CRS transmissions, then coherent combining is prevented, but measurement accuracy for high mobility UEs is improved
Solution Approach 1:
The patent applies different phase continuity properties to different CRS sequences based on local conditions. Specific sequences within the extended periodicity are designed with particular phase relationships suited for high mobility measurements, while other sequences maintain properties suitable for coherent combining. This localized differentiation allows each sequence to optimize for its specific measurement purpose
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Methods, systems, and devices are described for supporting common reference signaling in wireless communications systems. Some configurations introduce a phase discontinuity between common reference signal (CRS) transmissions on different subframes. This may address issues that may arise when a reduced CRS periodicity is utilized. Indicators may also be transmitted from base stations to user equipment (UEs) to indicate whether phase continuity may be assumed or not. Some configurations may support CRS sequence initialization. These tools and techniques may utilize an extended CRS sequence periodicity, which may increase the number of CRS sequences transmitted by a cell.