OTDOA Reference Signal Measurement Prioritization
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Solution Overview
Problem
The existing OTDOA positioning method in LTE networks faces challenges in accurately determining the geographical location of UE due to limitations in RSTD measurements, particularly when dealing with OTDOA neighbor cells with poor wireless channel quality, leading to inefficient use of resources and reduced measurement accuracy.
Innovation Solution
The method optimizes OTDOA measurements by dynamically selecting which OTDOA neighbor cells to perform RSTD measurements on based on channel quality metrics, prioritizing unmeasured and weak cells while minimizing measurements on strong and dummy cells, and aggregating multiple measurements to improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If RSTD measurements are performed on all OTDOA neighbor cells, then measurement completeness is improved, but power consumption and measurement time increase
Solution Approach 1:
The patent applies local quality by differentiating measurement strategies based on cell-specific channel quality. Cells are categorized into different groups (e.g., strong signal cells, weak signal cells, dummy cells) and measurement resources are allocated differently to each group. Weak signal cells receive more measurement opportunities while strong signal cells receive fewer, optimizing the balance between measurement accuracy and power consumption.
Solution Approach 2:
The patent changes the measurement parameter (number of measurements) based on channel quality conditions. The network configures different numbers of reference signal periods for measuring different cells according to their channel quality. This dynamic parameter adjustment allows the system to adapt measurement resources to actual needs, reducing unnecessary measurements on strong cells while ensuring adequate measurements on weak cells.
2Measurement precision
If RSTD measurements are performed on all OTDOA neighbor cells, then measurement completeness is improved, but measurement time increases
Solution Approach 1:
Different measurement strategies are applied to different cell groups based on local channel quality characteristics. Weak signal cells are assigned more measurement opportunities in the measurement configuration, while strong signal cells require fewer measurements. This localized differentiation reduces overall measurement time while maintaining accuracy for critical cells.
Solution Approach 2:
The patent applies partial action by performing measurements selectively rather than uniformly on all cells. Instead of allocating equal measurement resources to every cell, the system allocates measurements partially based on need - excessive measurements for weak cells and minimal measurements for strong cells. This selective approach reduces total measurement time while ensuring adequate coverage of critical measurements.
3Measurement precision
If multiple measurements are performed on weak cells, then measurement accuracy is improved, but power consumption and time increase
Solution Approach 1:
The measurement configuration parameter (number of reference signal periods) is changed based on cell channel quality. Weak cells are configured with higher measurement repetition counts to improve accuracy, while strong cells use lower counts. This parameter differentiation ensures that measurement efficiency is optimized by avoiding redundant measurements on strong cells while providing sufficient measurements on weak cells.
Solution Approach 2:
Measurement resources are distributed with local quality consideration - weak cells receive enhanced measurement resources (more repetitions, more periods) while strong cells receive standard or reduced resources. This localized resource allocation improves overall measurement efficiency by concentrating resources where they are most needed rather than uniformly distributing them.
4Measurement precision
If measurements are performed on dummy cells with poor channel quality, then measurement completeness is improved, but power consumption increases without meaningful results
Solution Approach 1:
The patent extracts and identifies dummy cells (cells with poor channel quality that cannot provide useful positioning information) from the measurement set. These dummy cells are then excluded or given minimal measurement opportunities in the measurement configuration. This extraction of harmful elements (dummy cells) prevents wasted power consumption on measurements that would not contribute to positioning accuracy.
Solution Approach 2:
The patent converts the harmful effect of including dummy cells in measurements by using channel quality information to identify and exclude them. The channel quality metrics that initially revealed the poor condition of these cells are now used to their advantage - by configuring the measurement system to avoid or minimize measurements on these cells, the system eliminates power waste while maintaining measurement completeness for viable cells.
Data Source
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AI summary
A method for performing reference signal measurements on a plurality of cells may include obtaining a plurality of channel quality metrics for the plurality of cells, assigning a plurality of cell measurement priority rankings to the plurality of cells based on the plurality of channel quality metrics, based on the plurality of cell measurement priority rankings, selecting one or more target cells from the plurality of cells to measure during one or more reference signal periods to obtain a plurality of reference signal measurements, and reporting the plurality of reference signal measurements to a communication network.