Random Access Procedure Optimization in Non-Terrestrial Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In Non-Terrestrial communication systems, the existing Random Access Procedure (RACH) is inefficient due to the large Cyclic Prefix (CP) and Guard Time (GT) required in RACH preambles, which significantly reduces the number of available RACH occasions for User Equipment (UE) and leads to delays in downlink control information arrival, especially in scenarios with varying propagation delays and multipath fading.
Innovation Solution
The method involves a User Equipment (UE) and a base station collaborating to determine a default Timing Advance (TA) based on altitude and beam information, allowing the UE to select an optimal RACH resource and configure reduced CP and GT lengths for the RACH preamble, thereby optimizing the random access procedure and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If large Cyclic Prefix (CP) and Guard Time (GT) are used in RACH preambles to compensate for propagation delay and multipath fading, then reliability of signal transmission is improved, but the number of available RACH occasions is reduced and access delay increases
Solution Approach 1:
The patent applies dynamics by making the CP and GT lengths variable rather than fixed. The base station configures different CP and GT lengths based on the UE's altitude information, creating a dynamic adaptation mechanism that optimizes the balance between reliability and access efficiency for different propagation conditions
Solution Approach 2:
The patent changes the parameters of CP and GT lengths based on altitude. By receiving altitude information from the UE and selecting appropriate CP/GT configurations from multiple options, the system adapts the time domain parameters to match the actual propagation delay characteristics, resolving the contradiction between using large values for reliability and small values for access efficiency
2Reliability
If large Cyclic Prefix (CP) and Guard Time (GT) are configured to cover maximum propagation delay, then coverage and reliability are improved, but power consumption increases and RACH procedure efficiency decreases
Solution Approach 1:
The patent optimizes power consumption by changing the CP and GT parameters based on actual altitude conditions. The UE receives altitude information, determines the appropriate propagation delay, and selects corresponding CP/GT configurations that are neither excessively large nor insufficient, thereby minimizing energy waste while ensuring reliable coverage
Solution Approach 2:
Instead of always using the maximum possible CP and GT lengths to ensure coverage, the patent applies partial action by selecting just the right amount of CP/GT needed for the specific altitude condition. This avoids the excessive action of always using maximum values, reducing power consumption while maintaining adequate coverage reliability
3Device complexity
If default Timing Advance (TA) is used for all UEs regardless of altitude, then system complexity is reduced, but accuracy of timing synchronization deteriorates
Solution Approach 1:
The patent applies local quality by providing different default TA values tailored to specific altitude ranges. Instead of a uniform TA for all UEs, the base station configures multiple default TA values corresponding to different altitude conditions, allowing each UE to select the appropriate TA based on its local altitude environment, thereby improving synchronization accuracy without excessive complexity
Solution Approach 2:
The patent changes the default TA parameter based on altitude information. The base station receives altitude data from the UE and selects an appropriate default TA value from multiple configured options, creating a parameter adaptation mechanism that improves timing synchronization accuracy while maintaining manageable system complexity through standardized configuration procedures
Data Source
AI summary
The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. Accordingly, the embodiments herein provides a method and system method for handling a random access procedure in a Non-Terrestrial communication system (300). The method includes obtaining, by a UE (100), a default TA, a RACH resource, and a RACH configuration list. Further, the method includes selecting, by the UE (100), the default TA and the RACH resource. Further, the method includes applying, by the UE (100), the selected default TA to the random access procedure. Further, the method includes performing, by the UE (100), the random access procedure based on the selected RACH resource and the selected default TA. The proposed method can be used to reduce the CP and GT in the RACH preambles, so as to optimize the random access procedure using the default TA.