Flexible OFDM Frame Structure for Spectrum Sharing
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Solution Overview
Problem
Current OFDM and OFDMA frame structures in mobile communication systems are rigid, limiting their ability to maximize performance in diverse deployment and operational conditions, particularly in scenarios with varying mobility and mixed-mode operations with legacy systems.
Innovation Solution
A flexible OFDM/OFDMA frame structure is introduced, featuring a configurable-length frame with variable subframes, enabling spectrum sharing and supporting legacy systems, with frame elements like frame partitions and unit subframes allowing dynamic configuration to adapt to different traffic patterns and environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a rigid frame structure is used in OFDM/OFDMA systems, then system simplicity and ease of implementation are maintained, but system performance and adaptability to diverse deployment conditions deteriorate
Solution Approach 1:
The frame structure is segmented into multiple configurable elements including frame partitions, subframes, and slots. Each element can be independently configured in terms of duration and resource allocation, allowing the system to adapt to different deployment scenarios by adjusting the number and size of these segments without requiring a complete redesign of the frame structure.
Solution Approach 2:
The frame structure transitions from a static, fixed configuration to a dynamic, configurable one. Parameters such as frame duration, subframe length, and resource block allocation can be adjusted in real-time based on traffic conditions, mobility requirements, and deployment environment, enabling the system to optimize performance for diverse scenarios including high mobility, low latency applications, and mixed legacy system operation.
2Productivity
If a fixed frame structure is used, then system overhead and complexity are reduced, but latency and throughput performance deteriorate
Solution Approach 1:
The frame structure employs configurable parameters including frame duration, subframe length, cyclic prefix length, and resource block allocation that can be dynamically adjusted. By changing these parameters based on channel conditions, traffic type, and mobility requirements, the system can optimize throughput and latency performance without requiring complex hardware modifications.
Solution Approach 2:
Different portions of the frame structure can be configured with different parameters to suit local requirements. For example, certain subframes can be allocated with shorter durations for low-latency traffic while other subframes use longer durations for bulk data transfer. Resource blocks within subframes can be independently configured for different users and services, allowing localized optimization throughout the frame structure.
3Adaptability or versatility
If legacy systems are supported through fixed frame structures, then backward compatibility is maintained, but spectrum sharing efficiency and performance in mixed-mode operation deteriorate
Solution Approach 1:
The configurable frame structure serves multiple functions simultaneously - it can operate in modes compatible with legacy systems while also supporting advanced features for high-performance applications. The same frame structure can be adapted to support both fixed TDD and flexible TDD operations, enabling a single system to serve diverse requirements including legacy device compatibility and modern high-throughput demands.
Solution Approach 2:
The patent introduces an additional dimension of configurability to the frame structure, allowing simultaneous support for multiple operation modes. By adding the capability to dynamically adjust frame parameters while maintaining a consistent structural framework, the system can accommodate legacy systems operating with traditional fixed frames while also enabling advanced flexible frame operations in the same spectrum, effectively adding a temporal and configurational dimension to spectrum sharing.
Data Source
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AI summary
A flexible OFDM/OFDMA frame structure technology for communication systems is disclosed. The OFDM frame structure technology comprises a configurable-length frame which contains a variable length subframe structure to effectively utilize OFDM bandwidth. Furthermore, the frame structure facilitates spectrum sharing between multiple communication systems.