Preemption Indicator Scheduling for Dynamic TDD OFDM Symbols
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently transmitting and receiving control channels, particularly in cellular networks, due to the dynamic nature of uplink and downlink traffic, which affects the allocation of orthogonal frequency division multiplexing (OFDM) symbols.
Innovation Solution
A method and apparatus are introduced to utilize a preemption indicator to dynamically manage OFDM symbols by classifying them into uplink, downlink, and flexible symbols, with a processor at the base station and user equipment monitoring and decoding signals based on this indicator to adapt to traffic changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Dynamic TDD is used to vary the number of OFDM symbols for uplink/downlink according to traffic directions, then spectral efficiency is improved, but the complexity of resource allocation and signal transmission increases
Solution Approach 1:
The patent segments the downlink transmission into multiple OFDM symbol groups (first group, second group, third group) with different preemption indicator monitoring requirements. The first group requires monitoring in both first and second slots, the second group requires monitoring only in the second slot, and the third group requires monitoring only in the first slot. This segmentation reduces the overall monitoring complexity for terminals while maintaining efficient resource utilization.
Solution Approach 2:
The patent implements dynamic slot configuration where the number and type of OFDM symbols (uplink, downlink, flexible) are varied according to traffic directions. The base station can dynamically adjust the slot structure to match instantaneous traffic demands, improving spectral efficiency while the preemption indicator mechanism manages the complexity of these dynamic changes.
2Measurement precision
If preemption indicators are transmitted frequently to manage dynamic resource allocation, then resource allocation accuracy is improved, but the overhead of control signaling increases
Solution Approach 1:
The patent divides downlink OFDM symbols into multiple groups and assigns different preemption indicator monitoring requirements to each group. This segmentation allows the system to transmit preemption indicators less frequently for certain symbol groups, reducing control signaling overhead while maintaining accurate resource allocation for critical transmissions.
Solution Approach 2:
The patent applies partial monitoring action where terminals monitor preemption indicators for only certain OFDM symbol groups depending on their configuration and traffic requirements. Not all symbol groups require full monitoring, which reduces the overall control signaling overhead while maintaining sufficient resource allocation accuracy for active transmissions.
3Adaptability or versatility
If OFDM symbols are dynamically reconfigured between uplink and downlink, then adaptability to traffic patterns is improved, but the reliability of uplink transmission timing may deteriorate
Solution Approach 1:
The patent configures OFDM symbols as uplink, downlink, or flexible symbols in advance using RRC signaling before dynamic reconfiguration occurs. This preliminary configuration establishes a reliable baseline timing structure that maintains uplink transmission reliability, while allowing dynamic adjustments within the pre-defined framework.
Solution Approach 2:
The patent applies different characteristics to different OFDM symbols by classifying them into uplink, downlink, and flexible categories with specific properties. Each symbol type has locally optimized characteristics suitable for its intended transmission direction, maintaining reliability for uplink symbols while enabling adaptability through flexible symbols that can be dynamically reassigned.
Data Source
AI summary
A base station of a wireless communication system is disclosed. The base station of the wireless communication includes a communication module, and a processor. The processor generates a preemption indicator indicating a preempted resource. In this case, the resource indicated by the preemption indicator does not include an orthogonal frequency divisional multiplexing (OFDM) symbol configured as an uplink (UL) symbol by a radio resource control (RRC) signal. The processor is configured to transmit the preemption indicator to a user equipment of the wireless system based on a predetermined period.