NTN Random Access Preamble Configuration for Propagation Delay
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Solution Overview
Problem
The performance degradation in performing random access in non-terrestrial network systems is a challenge due to increased cell radii and propagation delays, which affect the orthogonality of Zadoff-Chu sequences used for generating random access preambles.
Innovation Solution
The proposed solution involves dividing cyclic shift values into two sets, where the first set is applied to terrestrial networks and the second set is applied to non-terrestrial networks, with specific Zadoff-Chu sequence generation and configuration based on cell coverage, using ZCZ configuration information to maintain orthogonality and improve random access performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single set of cyclic shift values is used for random access preambles, then the system is simple to configure, but performance degrades in non-terrestrial networks with large cell radii and propagation delays
Solution Approach 1:
The patent segments the cyclic shift values into two distinct sets: a first set for terrestrial networks and a second set for non-terrestrial networks. Each set is optimized for its specific network type, allowing the system to maintain high random access performance in both environments without using a single complex configuration that would need to accommodate all scenarios.
Solution Approach 2:
The patent introduces dynamic selection of cyclic shift value sets based on network type. The system can adaptively choose which set to use depending on whether the device is operating in a terrestrial or non-terrestrial network, enabling optimal performance across varying conditions without permanent complexity in the configuration structure.
2Reliability
If Zadoff-Chu sequences are used for random access preambles, then orthogonality is maintained in terrestrial networks, but orthogonality degrades in non-terrestrial networks due to propagation delays
Solution Approach 1:
The patent applies local quality by providing different cyclic shift value configurations tailored to specific network environments. The first set of cyclic shift values is optimized for terrestrial networks with smaller cell radii, while the second set is optimized for non-terrestrial networks with larger cell radii and propagation delays, ensuring each environment receives the appropriate quality parameters for maintaining orthogonality.
Solution Approach 2:
The patent changes the cyclic shift parameters based on network type. By selecting different cyclic shift values from the appropriate set, the system adjusts the temporal and spectral characteristics of the Zadoff-Chu sequences to compensate for propagation delays in non-terrestrial networks, thereby maintaining orthogonality under different propagation conditions.
3Ease of operation
If the same cyclic shift values are used across all networks, then configuration is simplified, but random access performance degrades in NTN due to increased cell radii
Solution Approach 1:
The patent segments the configuration into two distinct sets of cyclic shift values, allowing simple selection based on network type rather than requiring complex adaptive algorithms. This segmentation maintains ease of operation through straightforward configuration while enabling optimized performance for NTN by providing dedicated parameters in the second set.
Solution Approach 2:
The patent creates a universal RACH configuration structure that serves multiple network types through a single framework. The configuration includes both sets of cyclic shift values and uses network type identification to select the appropriate set, providing multi-functionality that simplifies operation across different networks while maintaining specialized optimization for each network type.
Data Source
AI summary
Disclosed are a device and method for performing a random access in a non-terrestrial network system. A wireless transmission and reception method performed by a user equipment according to an embodiment of the present invention comprises the steps of: receiving random access channel (RACH) configuration information from a network node, wherein the RACH configuration information includes zero correlation zone (ZCZ) configuration information indicating at least one cyclic shift value (Ncs) among a plurality of cyclic shift values to be used for generating a random access preamble, the plurality of cyclic shift values are divided into a first set and a second set according to the cell coverage to which the value is applied, and the second set is applied to a cell coverage larger than the first set; generating the random access preamble on the basis of the Ncs, transmitting the random access preamble to the network node; receiving a response message to the random access preamble from the network node; and transmitting a message to the network node on the basis of the response message.