5G BWP CSI Measurement Gaps for Cross-Numerology Scheduling
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Solution Overview
Problem
Existing 5G wireless systems face challenges in efficiently determining and reporting channel state information (CSI) across different bandwidth parts (BWPs) due to varying subcarrier spacings, which affects downlink channel scheduling and resource allocation.
Innovation Solution
A wireless transmit/receive unit (WTRU) measures CSI in a target BWP during a measurement gap, determining the gap type based on subcarrier spacing and reporting the measured CSI in the current active BWP, using CSI-reference signals (CSI-RSs) to facilitate accurate downlink channel scheduling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the WTRU performs CSI measurements on multiple BWPs with varying subcarrier spacings, then the accuracy of downlink channel scheduling is improved, but the measurement time and complexity increase
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the measurement gap length based on the subcarrier spacing of the target BWP. When the target BWP has a larger subcarrier spacing, the measurement gap is shortened, and vice versa. This adaptive parameter adjustment allows the WTRU to efficiently measure CSI across BWPs with different numerologies while minimizing the total measurement time and reducing the impact on downlink channel scheduling.
2Measurement precision
If the WTRU measures CSI in the target BWP by receiving CSI-RS, then the channel state information accuracy is improved, but the device complexity and processing load increase
Solution Approach 1:
The patent applies preliminary action by configuring the WTRU with measurement gap patterns and CSI-RS resource indications in advance through RRC signaling. The network provides the WTRU with pre-configured measurement configurations including the association between measurement gaps and target BWPs, which reduces the real-time processing complexity during actual CSI measurements.
3Productivity
If the measurement gap length decreases with increasing target BWP subcarrier spacing, then the scheduling efficiency is improved, but the measurement precision may be compromised
Solution Approach 1:
The patent applies parameter changes by establishing a direct relationship between measurement gap length and target BWP subcarrier spacing. The measurement gap length is dynamically adjusted based on the numerology of the target BWP, with shorter gaps for larger subcarrier spacings and longer gaps for smaller subcarrier spacings. This adaptive approach maintains measurement precision while optimizing scheduling efficiency for different BWP configurations.
Data Source
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AI summary
Methods and systems are described herein for bandwidth part (BWP) operation in 5G wireless systems. A wireless transmit/receive unit (WTRU), configured with at least one bandwidth part (BWP), may receive a signal including an indication for the WTRU to perform measurements on a target BWP, which may be received as part of downlink control information (DCI) in the current active BWP. The WTRU may determine a measurement gap type based on at least one of a subcarrier spacing (SCS) of a current active BWP and a SCS of the target BWP. The WTRU may determine a measurement gap for the target BWP based on the measurement gap type. The WTRU may measure channel state information (CSI) in the target BWP during the measurement gap. The WTRU may send a report including the measured CSI in the current active BWP.