Dynamic Cyclic Prefix Configuration for Non-Terrestrial Networks
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Solution Overview
Problem
In non-terrestrial network communication systems, the excessive length of cyclic prefix (CP) in 5G NR protocols leads to waste and low utilization of CP resources, reducing transmission efficiency due to small multipath delay spread and direct-path dominance in satellite and high-altitude platform communication channels.
Innovation Solution
A communication method that dynamically configures CP resources by using two types of CPs, where the first-type CP carries unique data and the second-type CP carries duplicate data, optimizing CP length to match the multipath delay spread, thereby reducing waste and improving resource utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the length of the CP in the NR protocol is used in NTN communication, then the inter-symbol interference is suppressed, but the CP resources are wasted and utilization is low
Solution Approach 1:
The patent applies dynamics by making the CP length configurable and adaptable to different communication scenarios. The network device can dynamically select between first-type CP (longer length) and second-type CP (shorter length) based on the specific NTN communication requirements, transforming the static CP structure into a dynamic one that optimizes resource usage while maintaining interference suppression where needed
Solution Approach 2:
The patent implements local quality by differentiating between first-type CP and second-type CP with different lengths suited for different local conditions. The first-type CP is used when longer protection is needed, while the second-type CP is used when shorter length suffices, allowing each portion of the transmission to have the appropriate CP characteristics for its specific requirements
2Reliability
If the length of the CP in the NR protocol is used in NTN communication, then the channel protection is ensured, but the transmission efficiency is reduced
Solution Approach 1:
The patent enables dynamic adaptation of CP length to balance protection and efficiency. By configuring different CP lengths (first-type vs second-type) based on channel conditions and transmission requirements, the system achieves optimal channel protection only where necessary, thereby improving overall transmission efficiency without compromising reliability in critical scenarios
Solution Approach 2:
The patent changes the CP length parameter from a fixed value to a configurable parameter with at least two distinct length options. This parameter change allows the system to adjust the trade-off between channel protection and transmission efficiency by selecting appropriate CP lengths based on actual communication conditions
3Loss of energy
If the CP length is reduced to match the multipath delay spread, then the resource utilization is improved, but the inter-symbol interference suppression may be compromised
Solution Approach 1:
The patent resolves this contradiction through dynamic selection of CP length. The system can switch between shorter second-type CP (for better resource utilization) and longer first-type CP (for better interference suppression) based on real-time channel conditions, ensuring that interference suppression is maintained only when actually needed while optimizing resource utilization in other scenarios
Data Source
AI summary
Example communication methods and apparatus are described. One example method includes generating a first signal and sending a first signal, where the first signal includes an orthogonal frequency division multiplexing (OFDM) symbol, a first-type cyclic prefix (CP), and a second-type CP. CP resources of the first-type CP include two types of CP resources: a first CP resource and a second CP resource. CP resources of the second-type CP include one type of CP resource, that is, the second CP resource. The first CP resource may be used to carry data that is different from data carried on the OFDM symbol. The second CP resource may be used to carry data that is the same as the data carried on the OFDM symbol.