PRACH Time Gap Configuration for Wireless Random Access
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in the random access procedure, particularly in unlicensed bands, due to the lack of flexible time gap configurations between Random Access Channel (RACH) occasions, which can lead to increased latency and reduced resource efficiency.
Innovation Solution
The proposed solution involves configuring time gap durations between RACH occasions to be the same value regardless of subcarrier spacing changes, allowing for efficient transmission and reception of physical random access channels (PRACH) and random access responses (RAR) through specific processor-controlled devices, including user equipment (UE) and base stations (BS), using orthogonal frequency division multiplexing (OFDM) symbols, and employing Listen-Before-Talk (LBT) procedures to manage channel access in unlicensed bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If time gap durations between RACH occasions are configured to adapt to subcarrier spacing changes, then resource utilization efficiency improves, but system complexity and configuration overhead increase
Solution Approach 1:
The patent applies parameter changes by configuring time gap durations between RACH occasions based on subcarrier spacing values. Specifically, different time gap durations are assigned depending on whether the subcarrier spacing is 15 kHz or 30 kHz, allowing the system to optimize resource utilization for different numerologies while maintaining manageable configuration complexity through standardized parameter sets.
2Loss of time
If multiple different time gap durations are configured for different subcarrier spacing values, then random access latency is reduced, but device complexity increases
Solution Approach 1:
The patent reduces random access latency by changing the time gap duration parameter based on subcarrier spacing. When 30 kHz subcarrier spacing is used, a shorter time gap duration is configured compared to 15 kHz, enabling faster random access procedures. The UE and base station both support multiple time gap duration values and select the appropriate one based on the configured subcarrier spacing, thereby reducing latency without requiring complex adaptive algorithms.
3Device complexity
If time gap durations are fixed regardless of subcarrier spacing, then device complexity is reduced, but resource efficiency and latency performance deteriorate
Solution Approach 1:
The patent improves resource utilization efficiency by configuring appropriate time gap durations based on subcarrier spacing values. For 30 kHz subcarrier spacing, shorter time gaps are used to maximize resource efficiency and reduce idle time, while for 15 kHz spacing, longer time gaps are configured to maintain synchronization accuracy. This parameter adaptation allows the system to optimize resource efficiency for each numerology without requiring continuous real-time adjustments.
Data Source
AI summary
A method and device for transmitting and receiving a signal in a wireless communication system, according to one embodiment of the present invention, comprises transmitting a physical random access channel (PRACH) and receiving a random access response (RAR) on the basis of the PRACH, wherein the PRACH is transmitted via one random access channel (RACH) occasion (RO) of ROs in a RACH slot, timing gap durations exist between the ROs, and the same timing gap durations can be set even if a PRACH format and/or a subcarrier spacing (SCS) used for the PRACH are changed.