TDD Special Subframe Configuration for Half-Duplex Operation
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Solution Overview
Problem
In wireless communication systems using time division duplex (TDD), ensuring a half duplex operation across multiple cells with different time alignment values is challenging due to overlapping downlink and uplink signals, which can lead to interference and prevent guaranteed half duplex operation.
Innovation Solution
A wireless device adjusts the configuration of special subframes in multiple cells by changing the size of downlink pilot time slots and uplink pilot time slots when downlink reception and uplink transmission overlap, ensuring that at least one configuration is modified to prevent signal overlap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple serving cells with different time alignment values are configured to provide higher data rate, then data rate is improved, but downlink reception and uplink transmission may overlap causing interference
Solution Approach 1:
The patent applies dynamics by making the special subframe configuration adjustable and adaptable. The wireless device dynamically selects or modifies the configuration of at least one special subframe based on whether downlink reception and uplink transmission overlap occurs. This dynamic adjustment allows the system to maintain half-duplex operation while supporting multiple serving cells with different time alignment values, thereby resolving the contradiction between achieving high data rates and avoiding interference.
2Adaptability or versatility
If multiple serving cells with different time alignment values are configured, then coverage and frequency features are optimized, but half duplex operation cannot be guaranteed
Solution Approach 1:
The patent applies local quality by allowing different time alignment values to be applied to different serving cells based on their specific coverage and frequency requirements, while simultaneously applying a local adjustment to the special subframe configuration in the affected cell to prevent overlap. This localized configuration adjustment ensures that each cell can be optimized for its specific conditions while maintaining overall half-duplex operation reliability.
3Reliability
If downlink reception and uplink transmission overlap is prevented by adjusting special subframe configuration, then half duplex operation is guaranteed, but system flexibility is reduced
Solution Approach 1:
The patent applies partial action by adjusting the configuration of at least one special subframe rather than all special subframes across all cells. The wireless device identifies the specific special subframe configuration that causes overlap and modifies only that particular configuration. This partial adjustment approach maintains half-duplex operation reliability while preserving the flexibility and original configurations of other special subframes that do not cause interference.
Data Source
AI summary
Provided are a communication method and a wireless device in a time division duplex (TDD)-based wireless communication system. A wireless device receives a setting for a first special (S) subframe of a first cell to which a first timing advance (TA) is applied and a setting for a second S subframe of a second cell to which a second TA is applied. When a downlink (DL) reception and an uplink (UL) transmission are duplicated, the wireless device varies at least one of the settings among the first S subframe and second S subframe.