LTE Scheduling Method for Diverse Subcarrier Spacing Support
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Solution Overview
Problem
The existing LTE system does not support terminals with subcarrier spacings other than 15 kHz, limiting the scheduling granularity and preventing the use of terminals that can send single subcarriers with 3.75-kHz or multiple subcarriers with 15-kHz spacings, as these do not align with the system's frame structure designed for 15-kHz spacings.
Innovation Solution
A scheduling method that includes sending downlink control information to instruct terminals to use specific frame formats, where the first-type terminal uses a first-mode frame format with uplink subframes lasting at least four times as long as standard SC-FDMA symbols, and second-type and third-type terminals use second-mode frame formats with 10 subframes and 15-kHz subcarrier spacing, allowing for flexible resource allocation and support of diverse terminal capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the LTE system uses a fixed frame structure designed for 15-kHz subcarrier spacing, then the system can maintain standardized scheduling granularity and compatibility, but it cannot support terminals with different subcarrier spacings (e.g., 3.75-kHz or other configurations)
Solution Approach 1:
The patent introduces dynamic frame format configuration where the base station can select between a first mode frame format (for terminals with 3.75-kHz subcarrier spacing) and a second mode frame format (for terminals with 15-kHz subcarrier spacing). This dynamic adaptation allows the system to accommodate different terminal capabilities without requiring a completely new fixed frame structure for each configuration, thereby resolving the contradiction between adaptability and complexity.
Solution Approach 2:
The patent changes the frame format parameters based on terminal capability. Specifically, it defines different frame structures with different numbers of symbols and different subcarrier spacing configurations. By modifying these parameters dynamically according to the terminal type, the system achieves versatility in supporting multiple subcarrier spacings while maintaining a manageable level of complexity through parameterization rather than structural redesign.
2Adaptability or versatility
If the system supports multiple terminal types with different subcarrier spacings, then terminal compatibility is improved, but the scheduling complexity and resource allocation difficulty increase
Solution Approach 1:
The patent segments the terminal population into different categories (first-type terminals with 3.75-kHz spacing and second-type terminals with 15-kHz spacing) and assigns different frame formats to each segment. This segmentation allows the base station to simplify scheduling operations by treating different terminal types with dedicated, pre-configured frame formats, rather than attempting to manage all terminals with a single complex unified scheduling mechanism.
Solution Approach 2:
The patent introduces frame format configuration as an intermediary layer between the base station and terminals. The base station determines the appropriate frame format based on terminal capability and transmits control information accordingly. This intermediary mechanism simplifies scheduling operations by providing a structured approach to handling different terminal types, acting as a mediator that translates terminal capabilities into manageable scheduling decisions.
3Device complexity
If the system uses a unified frame structure for all terminals, then device complexity is reduced, but it cannot accommodate terminals with different subcarrier spacings and capabilities
Solution Approach 1:
The patent employs dynamic frame format selection where the base station can switch between a first mode frame format and a second mode frame format depending on terminal capability. This dynamic approach maintains relative simplicity by using a limited set of predefined frame formats rather than creating entirely different structures for each terminal type, while still providing the necessary scheduling flexibility to accommodate various subcarrier spacings.
Solution Approach 2:
The patent creates a universal scheduling framework that can handle multiple terminal types through a single base station implementation. By defining multiple frame formats that the base station can select from, the system achieves multi-functionality where one base station structure can serve both first-type and second-type terminals, maintaining simplicity at the system level while providing adaptability at the terminal level.
Data Source
AI summary
Embodiments of the present invention provide a scheduling method, a data transmission method, and an apparatus, and relate to the field of communications technologies, so as to resolve a problem that an existing LTE system does not support a new type of terminal. The scheduling method includes: sending, by a base station, downlink control information DCI to a first-type terminal, where the DCI includes scheduling information used to instruct the first-type terminal to send uplink data by using a first-mode frame format; the first-mode frame format includes at least one uplink subframe, and each uplink subframe includes at least one first-mode frame format symbol; and duration of the first-mode frame format symbol is at least four times of duration of a second-mode frame format symbol, and the second-mode frame format symbol is a single carrier frequency division multiple access SC-FDMA symbol in an LTE system.