PTRS-DMRS Port Mapping for Multi-TCI PDSCH Repetitions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the New Radio (NR) system, the existing association between phase tracking reference signal (PTRS) antenna ports and DMRS antenna ports is inadequate when multiple repeated versions are transmitted in the same slot, leading to inaccurate phase noise estimation due to insufficient PTRS antenna ports and unclear time-frequency resources.
Innovation Solution
A method and apparatus for determining the association relationship between PTRS and DMRS antenna ports, including configuration or indication information to support multiple PTRS antenna ports for accurate phase noise estimation, and modifying transmission behaviors to ensure distinct time-frequency resources for each PTRS antenna port.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple repeated versions are transmitted in the same slot using beamforming technique, then transmission reliability is improved, but the existing PTRS antenna port association with DMRS antenna ports becomes insufficient, leading to inaccurate phase noise estimation
Solution Approach 1:
The patent segments the association relationship between PTRS and DMRS antenna ports by introducing a mapping rule that associates each PTRS antenna port with a specific DMRS antenna port based on port indexing. This segmentation allows multiple PTRS antenna ports to be independently associated with different DMRS antenna ports, enabling accurate phase noise estimation for each transmission layer even when multiple repeated versions are transmitted in the same slot.
2Measurement precision
If multiple PTRS antenna ports are introduced to support multiple noise sources, then phase noise estimation accuracy is improved, but time-frequency resource allocation becomes complex and unclear
Solution Approach 1:
The patent changes the parameter of PTRS antenna port association by introducing a mapping rule based on port indexing. Instead of using a fixed or ambiguous association, the patent dynamically determines the association based on the DMRS antenna port index, which clearly identifies the time-frequency resources. This parameter change resolves the complexity in resource allocation while supporting multiple PTRS antenna ports for accurate phase noise estimation.
3Device complexity
If identical DMRS antenna ports are used for all repeated versions in Rel-15, then device complexity is reduced, but the number of PTRS antenna ports becomes insufficient when multiple transmission points are used
Solution Approach 1:
The patent introduces dynamic adaptation of DMRS antenna port usage based on the transmission scenario. When multiple transmission points are used, the system dynamically assigns different DMRS antenna ports to different repeated versions, which in turn enables the corresponding PTRS antenna ports to be properly associated. This dynamic approach maintains simplicity in single-TRP scenarios while supporting multi-TRP transmissions without increasing overall system complexity.
Data Source
AI summary
A terminal apparatus includes: a receiver configured to: receive, from a network device, configuration information that is carried by a higher layer parameter, receive, from the network device, indication information, and receive physical downlink shared channel (PDSCH) transmission occasions of the same transport block in a scheduling unit according to the configuration information and the indication information, the PDSCH transmission occasions including a first PDSCH transmission occasion and a second PDSCH transmission occasion; and processor circuitry configured to determine a demodulation reference signal (DMRS) antenna port and an associated a phase tracking reference signal (PTRS) antenna port for each of the PDSCH transmission occasions according to an association relationship indicated by the configuration information, wherein the indication information indicates: a first transmission configuration indication (TCI) state for the first PDSCH transmission occasion, and a second TCI, which is different from the first TCI state, for the second PDSCH transmission occasion.