PRACH Preamble Hopping by Coverage Level for NR-Superlight UEs
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Solution Overview
Problem
Existing wireless communication systems, particularly for low-power devices like NR-Superlight UEs, face challenges in achieving sufficient bandwidth and coverage enhancement for reliable random access channel (RACH) procedures due to limited bandwidth and coverage issues, which are not adequately addressed by current frequency hopping patterns.
Innovation Solution
Implementing frequency hopping patterns tailored for each PRACH coverage enhancement level, including intra-band and inter-band frequency hopping, to improve RACH procedures for bandwidth-limited UEs like NR-Superlight devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency hopping patterns are implemented for PRACH transmission, then frequency diversity gain is improved, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by configuring different frequency hopping patterns (first and second hopping patterns with different hopping sizes) based on coverage enhancement levels. The network configures specific hopping parameters through RRC signaling, allowing the UE to switch between patterns without increasing hardware complexity, thereby improving frequency diversity while maintaining manageable device complexity through software-configurable parameters.
Solution Approach 2:
The patent implements dynamics by enabling the UE to dynamically switch between different frequency hopping patterns based on the selected coverage enhancement level. The hopping pattern is not fixed but adapts according to the CE level determined by path loss measurements, allowing the system to optimize frequency diversity gain while controlling complexity through adaptive selection rather than simultaneous implementation of all patterns.
2Area of stationary object
If multiple frequency hopping patterns are configured for different coverage enhancement levels, then coverage is improved, but signaling overhead increases
Solution Approach 1:
The patent applies segmentation by dividing the frequency hopping configuration into multiple discrete patterns (first hopping pattern and second hopping pattern) associated with different coverage enhancement levels. Each pattern is configured with specific hopping sizes suitable for its intended CE level, allowing the network to provide targeted frequency diversity without overwhelming the UE with a single complex configuration. The segmentation reduces signaling overhead by providing modular, level-specific configurations.
Solution Approach 2:
The patent implements local quality by tailoring the frequency hopping pattern characteristics to specific coverage enhancement levels. The first hopping pattern with its specific hopping size is optimized for lower CE levels, while the second hopping pattern with different hopping size is optimized for higher CE levels. This localized optimization ensures that each configuration provides appropriate frequency diversity for its intended coverage scenario without requiring all UEs to handle all possible configurations, thereby reducing overall signaling overhead.
Data Source
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AI summary
Disclosed are techniques for wireless communication. In an aspect, a UE determines a frequency hopping pattern for transmission of a physical random access channel (PRACH) preamble based on an associated PRACH coverage enhancement (CE) level, and transmits the PRACH preamble in accordance with the frequency hopping pattern and the associated PRACH CE level. A base station receives the PRACH preamble, and transmits a response (e.g., Msg2 or MsgA) to the PRACH preamble.