UE-Assisted SRS Resource Allocation for 5G Beam Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In 5G wireless networks, the lack of beam correspondence between transmit (TX) and receive (RX) antennas due to non-ideal analog beamforming components leads to inconsistent TX and RX antenna patterns, necessitating effective uplink beam-management techniques to determine suitable TX beam directions for data transmission.
Innovation Solution
The system employs dynamic UE capability messages to communicate the number of beam directions associated with different antenna arrays, allowing the TRP to assign SRS resources and schedule multi-layer MIMO uplink transmissions in accordance with UE beamforming capabilities, ensuring consistent resource allocation and beam management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If beamforming is used to compensate for high path loss at mmW frequencies, then signal quality is improved, but TX and RX antenna patterns become inconsistent due to non-ideal analog beamforming components
Solution Approach 1:
The patent inverts the traditional approach by having the UE determine its own TX beam directions based on downlink measurements rather than relying on the network to configure them. The UE measures downlink reference signals (DL-RS) using different RX beam directions, identifies corresponding beam directions, and autonomously determines TX beam directions based on these measurements, thereby bypassing the antenna pattern inconsistency issue.
Solution Approach 2:
The UE performs self-service by autonomously selecting and determining beam directions without requiring complex network configuration or calibration. The UE measures downlink signals, processes the measurements locally, and independently determines the optimal TX beam directions, reducing the burden on the network and avoiding the antenna pattern consistency problem.
2Device complexity
If the network configures SRS resources without UE beam capability information, then resource allocation is simplified, but beam management accuracy deteriorates
Solution Approach 1:
The patent applies preliminary action by having the UE determine TX beam directions and report beam capability information to the network before SRS resource allocation. The network then uses this pre-reported information to configure SRS resources accurately, achieving both simplified allocation procedures and high beam management precision.
3Adaptability or versatility
If the UE reports all possible beam directions, then beam management flexibility is improved, but uplink transmission overhead increases
Solution Approach 1:
The patent extracts only the essential beam direction information from the full set of possible beam directions. The UE determines TX beam directions corresponding to the best downlink beam directions and reports only these relevant directions to the network, rather than reporting all possible beam directions, thereby reducing uplink overhead while maintaining beam management flexibility.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A dynamic UE capability message specifying a number of beams to be evaluated within different groups of UE TX beam directions associated with different antenna arrays of a UE may be communicated to a transmit receive point (TRP). Each group of UE TX beam directions may include beam directions that are candidates for uplink data transmission. Based on information in the dynamic UE capability message, the TRP can assign SRS resources (for uplink beam management or uplink channel sounding) and/or schedule a multi-layer MIMO uplink transmission in accordance with a UE capability constraint. This may ensure that the SRS resources assignment and/or scheduled multi-layer MIMO uplink transmission is consistent with the UE's beamforming capabilities.