QCL Beam Estimation Using TRS and TCI States
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Solution Overview
Problem
In beam-based communication, the current quasi-colocation (QCL) assumption process in terminal devices inaccurately determines receive beams due to reliance on synchronization signals, leading to inefficient signal reception and demodulation, particularly in high-frequency environments.
Innovation Solution
The method involves using a more accurate QCL reference by incorporating channel state information reference signals (CSI-RS) and transmission configuration indicators (TCI states) to determine receive beams, reducing reliance on synchronization signals alone, thereby improving beam estimation and communication efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal device uses SSB as the default QCL reference for beam estimation, then the initial access process can be completed, but the accuracy of receive beam determination deteriorates
Solution Approach 1:
The patent applies preliminary action by configuring TRS resources and QCL parameters in advance through RRC signaling before the terminal device needs to receive data. The network device pre-configures multiple TRS resources with different QCL parameters, so when data reception is needed, the terminal device can directly use the pre-configured TRS as QCL reference without relying on the inaccurate SSB-based beam estimation from initial access.
Solution Approach 2:
The patent changes the QCL reference parameter from SSB to TRS. By introducing TRS as a new reference signal type with configurable QCL parameters, the system transitions from using synchronization signal-based beam estimation to TRS-based beam estimation, thereby improving measurement precision while maintaining reliability.
2Device complexity
If the terminal device relies on SSB for QCL assumption, then the system complexity remains low, but signal reception efficiency deteriorates
Solution Approach 1:
The patent segments the QCL reference signal functionality into different types: SSB for initial access and TRS for data reception. By dividing the reference signal purposes, the system can use simple SSB for basic access while employing more sophisticated TRS for efficient data reception, thereby improving productivity without significantly increasing overall system complexity.
Solution Approach 2:
The patent introduces TRS as an intermediary between SSB and data channels. TRS serves as a bridge that provides accurate QCL parameters for data reception while being separately configurable and transmittable. This intermediary allows the system to maintain low complexity in initial access while achieving high efficiency in signal reception through the TRS mediation.
3Measurement precision
If the network device configures multiple TRS resources with different QCL parameters, then the beam estimation accuracy improves, but the configuration complexity increases
Solution Approach 1:
The patent applies dynamics by making the TRS configuration flexible and adaptable. The network device can dynamically configure multiple TRS resources with different QCL parameters based on channel conditions and terminal capabilities. The terminal device can select the most appropriate TRS resource from the configured set, allowing the system to adapt to varying conditions while maintaining manageable configuration complexity through standardized procedures.
Data Source
AI summary
This application provides example signal transmission methods and communications apparatuses. One example method includes receiving first configuration information, where the first configuration information includes at least one transmission configuration indicator (TCI) state and a configuration of a tracking reference signal (TRS) of a first channel, and the TRS is a set including a plurality of channel state information reference signal (CSI-RS) resources. A quasi-colocation (QCL) parameter of the first channel is determined based on one or more of a first CSI-RS resource in a plurality of CSI-RS resources included in a first TRS in the TRS, a first TC state in the at least one TCI state, and a synchronization signal and PBCH block (SSB). The first channel is then received on the QCL parameter of the first channel.