Flexible OFDM Waveform Adaptation for Wireless Spectrum Efficiency
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Solution Overview
Problem
Conventional OFDM systems with fixed sub-carrier spacing and symbol duration are inadequate for next-generation wireless networks, which require higher mobility, lower latency, and varied deployment environments, limiting spectrum efficiency and Quality of Service (QoS).
Innovation Solution
Implementing variable sub-carrier spacing and symbol duration using frequency-time primitives, with multiple access blocks (MABs) of different configurations to support diverse channel conditions and user equipment capabilities, allowing for flexible OFDM waveform adaptations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single standardized OFDM waveform is used, then transmitter and receiver designs are simplified and implementation complexity is reduced, but performance in diverse deployment scenarios and channel conditions deteriorates
Solution Approach 1:
The patent implements dynamic waveform adaptation by enabling the system to switch between different OFDM configurations (subcarrier spacings, symbol durations, cyclic prefix lengths) based on real-time channel conditions and deployment scenarios. This dynamic selection allows the system to optimize performance for each specific scenario while maintaining a unified underlying OFDM framework, thus resolving the contradiction between design simplicity and adaptability.
Solution Approach 2:
The patent changes key OFDM parameters (subcarrier spacing, symbol duration, cyclic prefix length) to adapt to different channel conditions and deployment scenarios. By providing multiple standardized parameter sets that can be selected based on specific requirements, the system maintains implementation simplicity while achieving versatility across diverse scenarios.
2Ease of manufacture
If fixed sub-carrier spacing and symbol duration are used, then system implementation is simplified, but spectral efficiency and QoS support for diverse scenarios deteriorate
Solution Approach 1:
The patent segments the OFDM parameter space into multiple standardized configurations, each optimized for specific scenarios. By dividing the parameter space into discrete, well-defined options (different subcarrier spacings, symbol durations, cyclic prefix lengths), the system maintains implementation simplicity while enabling selective optimization for different deployment scenarios, thus improving spectral efficiency without sacrificing ease of implementation.
3Device complexity
If a single waveform configuration is used, then device complexity is reduced, but support for higher mobility and lower latency scenarios deteriorates
Solution Approach 1:
The patent enables dynamic selection of OFDM waveform configurations based on channel conditions, mobility requirements, and latency constraints. By providing multiple standardized configurations that can be adaptively selected, the system maintains low device complexity while achieving high reliability across diverse channel conditions including high mobility and low latency scenarios.
Data Source
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AI summary
Embodiments are provided for supporting variable sub-carrier spacing and symbol duration for transmitting OFDM or other waveform symbols and associated cyclic prefixes. The symbol duration includes the useful symbol length and its associated cyclic prefix length. The variable sub-carrier spacing and symbol duration is determined via parameters indicating the sub-carrier spacing, useful symbol length, and cyclic prefix length. An embodiment method, by a network or a network controller, includes establishing a plurality of multiple access block (MAB) types defining different combinations of sub-carrier spacing and symbol duration for waveform transmissions. The method further includes partitioning a frequency and time plane of a carrier spectrum band into a plurality of MAB regions comprising frequency-time slots for the waveform transmissions. The MAB types are then selected for the MAB regions, wherein one MAB type is assigned to one corresponding MAB region.