Numerology-Dependent Random Access Timing in Wireless Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication systems face inconsistencies in random access channel (RACH) timing due to varying subframe durations, leading to inefficiencies in communication procedures between user equipment (UE) and base stations.
Innovation Solution
Implementing numerology-dependent random access timing, where different numerologies are used for the RACH procedure, with the base station transmitting an indication of the numerology to the UE, allowing for the determination of a minimum time gap for communication, thereby synchronizing communication processes based on tone spacing and symbol duration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed time interval (subframe) is used for RACH timing, then the timing specification is simple, but the varying subframe durations lead to inconsistent RACH timing
Solution Approach 1:
The patent applies parameter changes by transitioning from a fixed time interval parameter to a numerology-dependent parameter. The RACH timing is no longer based on a fixed subframe duration but is instead determined by the numerology (e.g., 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz) which defines the actual time characteristics. This allows the timing to adapt to different numerologies and maintain consistency across varying subframe durations.
2Adaptability or versatility
If different numerologies are used for RACH procedure, then the communication can adapt to varying conditions, but the RACH timing becomes more complex
Solution Approach 1:
The patent introduces an intermediary mechanism in the form of a lookup table or predefined mapping that connects the numerology indication to the corresponding RACH timing parameters. Instead of the UE calculating the timing based on complex formulas, the system uses this intermediary structure to translate the numerology indication (e.g., 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz) into the appropriate time gap and timing characteristics, thereby maintaining adaptability while simplifying the UE's processing requirements.
3Adaptability or versatility
If the RACH timing is extended to accommodate longer subframe durations, then all numerologies can be supported, but the communication latency increases
Solution Approach 1:
The patent implements dynamics by making the RACH timing parameters variable rather than fixed. The time gap and timing characteristics dynamically adjust based on the specific numerology being used. For higher numerologies (e.g., 60 kHz, 120 kHz, 240 kHz) with shorter subframe durations, the timing parameters are reduced accordingly, allowing the system to maintain fast response times while still supporting all numerologies from 15 kHz to 240 kHz.
Data Source
AI summary
Methods, systems, and devices for random access channel (RACH) timing in a wireless communication are described. A base station and a user equipment (UE) may perform a RACH procedure to establish a communication link between the base station the UE. The RACH timing associated with the RACH procedure may depend on the numerology used for the RACH procedure and may be conveyed by the base station to the UE in a control message or via system information. In some cases, the numerology may indicate the RACH timing, which may be used to determine a number of symbols or absolute time to be used for portions of the RACH procedure.