Supplemental Uplink Band Positioning for Power-Limited 5G Devices
Solution Overview
Problem
Current 5G wireless communication systems face challenges in accurately determining the position of mobile devices, particularly in areas where uplink data signals are power limited, and existing positioning methods are inefficient in enhancing spectral efficiency and reducing latency.
Innovation Solution
A location server is configured to provide OFDM UL-PRS resources in a second frequency band to user equipment (UE) when it is outside the uplink coverage area of a serving cell, using a supplemental uplink band to enhance positioning accuracy and coverage, and to coordinate with companion cells for multi-cell positioning techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If positioning is performed using uplink data signals in the first frequency band, then positioning can be performed within the coverage area, but positioning accuracy deteriorates in power-limited conditions where UE is outside uplink coverage area
Solution Approach 1:
The patent introduces a second frequency band (supplemental uplink band) as an additional dimension for positioning operations. When the UE is outside the uplink coverage area of the serving cell in the first frequency band, the location server identifies the second frequency band and provides OFDM UL-PRS resources in this alternative band, enabling positioning to proceed through a different operational dimension rather than failing completely.
Solution Approach 2:
The patent changes the frequency band parameter from the first frequency band to the second frequency band when uplink coverage is insufficient. This parameter change allows the system to adapt to varying coverage conditions and maintain positioning capability by switching to a frequency band where the UE can still transmit uplink positioning reference signals effectively.
2Productivity
If conventional positioning methods are used in 5G networks, then basic positioning functionality is provided, but spectral efficiency is insufficient and latency is high
Solution Approach 1:
The location server proactively determines whether the UE is within downlink coverage but outside uplink coverage area before positioning fails. By identifying coverage conditions in advance and preemptively providing OFDM UL-PRS resources in the second frequency band, the system avoids positioning delays and maintains continuous positioning capability without waiting for coverage failures.
Solution Approach 2:
The patent introduces the location server as an intermediary that coordinates between the serving cell and companion cells in the second frequency band. The location server provides PRS indications that enable the UE to transmit positioning signals through companion cells, facilitating positioning in power-limited conditions without requiring direct uplink coverage from the serving cell.
Data Source
AI summary
A method of indicating resources for uplink-based positioning includes: determining whether a UE is within a downlink coverage area of a serving cell, for a first frequency band and a transmit power of the serving cell, and outside an uplink coverage area of the serving cell for the first frequency band and a transmit power of the UE; identifying a second frequency band supported by the UE, the second frequency band including frequencies below a lowest frequency of the first frequency band; and providing at least one PRS indication indicating at least OFDM UL-PRS resources in the second frequency band for the UE based on a determination that the UE is outside the uplink coverage area of the serving cell for the first frequency band and the transmit power of the UE.