RACH Occasion Selection Using RSRP Thresholds in Subband Full-Duplex
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Solution Overview
Problem
In subband full-duplex communication, UEs face challenges in determining appropriate RACH occasions due to potential interference and increased path loss, leading to radio link failures and degraded system performance.
Innovation Solution
A method and apparatus for a UE to determine RACH occasions based on comparing the RSRP for the DL pathloss reference with an SBFD threshold, selecting either SBFD or non-SBFD symbol-based RACH resources, ensuring optimal power configuration and minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RACH occasions are determined without considering SBFD conditions, then the RACH procedure can be performed using standard resources, but interference and path loss increase leading to radio link failures
Solution Approach 1:
The patent changes the parameter of RACH occasion selection by introducing an RSRP threshold comparison mechanism. When the RSRP of DL pathloss reference is below the threshold, the UE selects non-SBFD RACH occasions; when above, SBFD RACH occasions are selected. This dynamic parameter adjustment resolves the contradiction by adapting RACH resource selection to current channel conditions, thereby reducing interference and path loss impacts while maintaining reliable random access.
Solution Approach 2:
The patent implements a dynamic RACH occasion determination mechanism where the UE continuously monitors RSRP levels and adapts its RACH resource selection accordingly. This dynamic behavior allows the system to switch between SBFD and non-SBFD RACH occasions based on real-time channel quality, resolving the contradiction between maintaining standard procedure simplicity and avoiding interference-induced failures.
2Productivity
If SBFD symbol-based RACH resources are used when RSRP is high, then spectral efficiency is improved, but radio link failures occur when RSRP is low
Solution Approach 1:
The patent introduces an RSRP threshold parameter that dynamically controls the selection between SBFD and non-SBFD RACH occasions. When RSRP exceeds the threshold, SBFD resources are utilized to maximize spectral efficiency; when below, non-SBFD resources ensure reliable transmission. This parameter-based adaptation resolves the contradiction by optimizing the trade-off between spectral efficiency and radio link stability based on current channel conditions.
Solution Approach 2:
The patent implements a dynamic switching mechanism where the UE adapts its RACH resource selection based on real-time RSRP measurements. This dynamic approach allows the system to exploit SBFD resources for high spectral efficiency when channel conditions permit, while automatically falling back to more robust non-SBFD resources when reliability is compromised, thus resolving the contradiction between productivity and reliability.
3Device complexity
If RACH configuration does not differentiate between SBFD and non-SBFD conditions, then configuration complexity is reduced, but system performance degrades due to interference
Solution Approach 1:
The patent introduces an RSRP threshold parameter that dynamically controls the selection between SBFD and non-SBFD RACH occasions. When the RSRP of DL pathloss reference is below the threshold, the UE selects non-SBFD RACH occasions; when above, SBFD RACH occasions are selected. This parameter-based approach resolves the contradiction by enabling performance optimization through conditional configuration without requiring complex separate configuration structures for different SBFD scenarios.
Data Source
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AI summary
Provided are a method and apparatus for determining random access channel (RACH) occasions in a sub-band full-duplex (SBFD) wireless communication system. The method of the terminal may include receiving random access channel (RACH) configuration information including a reference signal received power (RSRP) threshold for subband full duplex (SBFD) from a base station, comparing an RSRP for a downlink (DL) pathloss reference with the RSRP threshold for the SBFD, and determining at least one RACH occasion based on the comparison result.