Flexible 5G NR Frame Structures for Lower CP Overhead
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Solution Overview
Problem
The existing 5G NR standard suffers from high cyclic prefix (CP) overheads and inefficient resource scheduling due to abundant multipath channels, leading to increased redundancy and blind detection overheads.
Innovation Solution
A flexible frame structure is designed with different types of symbols, where first-type symbols carry control channels or null signals, and second-type symbols carry data channels, allowing for reduced CP redundancy and blind detection overheads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cyclic prefix is used to constitute a cyclic convolution characteristic for frequency domain equalization in 5G NR, then frequency domain equalization performance is improved, but CP overhead increases to about 7%, reducing system efficiency
Solution Approach 1:
The patent applies dynamics by making the CP configuration flexible and adaptable to different channel conditions. The network device can dynamically select between first-type symbols (with CP) and second-type symbols (without CP) based on multipath delay characteristics, allowing the system to optimize between equalization performance and overhead reduction in real-time
Solution Approach 2:
The patent implements local quality by applying CP only where necessary. First-type symbols with CP are used in specific time-frequency resources where multipath interference exists, while second-type symbols without CP are used where channel conditions permit, thereby reducing overall CP overhead while maintaining equalization performance where needed
2Ease of manufacture
If a fixed frame structure is used in 5G NR, then implementation is simplified, but CP redundancy increases and scheduling flexibility is reduced
Solution Approach 1:
The patent transforms the fixed frame structure into a dynamic one by introducing two types of symbols that can be flexibly configured. The network device can adaptively determine the quantity and distribution of first-type and second-type symbols based on channel conditions, reducing CP redundancy while maintaining implementation feasibility through standardized procedures
3Adaptability or versatility
If control channels are distributed across multiple slots, then resource scheduling flexibility is improved, but blind detection overhead and control information overhead increase
Solution Approach 1:
The patent applies segmentation by separating control channel functions into different symbol types. First-type symbols are dedicated to control channels with first CP for robust reception, while second-type symbols carry data with second CP (or no CP). This segmentation allows control information to be concentrated in specific symbols, reducing blind detection overhead while maintaining scheduling flexibility
Solution Approach 2:
The patent implements local quality by providing enhanced protection (first CP) only to control channel symbols where it is most needed for reliable detection, while data symbols use different CP configurations. This localized quality enhancement reduces overall overhead while maintaining scheduling flexibility
Data Source
AI summary
Embodiments of this application provide a communication method and a communication apparatus. The method includes: a first communication apparatus may design a frame structure parameter based on a multipath performance requirement by using an additional control channel, to specifically determine a length of a subframe, a quantity of slots in the subframe, and a quantity of first-type symbols and a quantity of second-type symbols in the subframe. A 1st symbol in the first-type symbols corresponds to a first cyclic prefix, and a symbol in the second-type symbols corresponds to a second cyclic prefix. Therefore, CP redundancy can be reduced, control channel overheads and blind detection overheads of a user can be reduced, network resource scheduling flexibility can be improved, and system efficiency can be improved.