Dynamic TDD Sub-frame Configuration for Inter-cell Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The current LTE TDD system experiences inter-cell interference when uplink and downlink sub-frame configurations differ between cells, leading to resource wastage and disruptions in uplink and downlink measurements and HARQ processes.
Innovation Solution
A dynamic sub-frame configuration method where resources in specific timeslots or bandwidths are silenced in one cell to match the silenced resources in neighboring cells, allowing only non-silenced resources to transmit information, thereby reducing inter-cell interference and ensuring uninterrupted measurements and resource utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If different uplink and downlink sub-frame configurations are adopted in neighboring cells to increase spectrum effectiveness, then the spectrum utilization ratio is improved, but inter-cell interference occurs
Solution Approach 1:
The patent applies local quality by configuring different sub-frame patterns in different regions (cells) based on local traffic characteristics. Each cell can independently select from multiple TDD configuration patterns (e.g., Pattern 1 with more downlink sub-frames, Pattern 2 with more uplink sub-frames) to match its specific service requirements, thereby optimizing spectrum utilization locally while managing interference through coordinated configuration across neighboring cells.
2Productivity
If sub-frame configuration is changed to match service requirements, then spectrum effectiveness is improved, but uplink and downlink measurements are disrupted
Solution Approach 1:
The patent applies preliminary action by establishing a set of predetermined TDD configuration patterns (e.g., Patterns 1-6 with different uplink-downlink sub-frame ratios) before actual deployment. These pre-defined patterns ensure that when cells change their sub-frame configuration to optimize spectrum effectiveness, the changes are made in a controlled manner that preserves measurement capabilities, as the patterns are designed to maintain necessary uplink and downlink sub-frames for measurement purposes.
3Adaptability or versatility
If sub-frame configuration is changed to optimize service capacity, then service requirements are met, but HARQ processes are interrupted
Solution Approach 1:
The patent applies parameter changes by allowing dynamic adjustment of sub-frame configuration parameters (uplink-downlink ratio, specific sub-frame assignments) to match varying service requirements. The system can switch between different TDD patterns (e.g., from Pattern 1 with 60% downlink to Pattern 2 with 40% downlink) based on traffic conditions, while the configuration changes are designed to maintain HARQ timing relationships and process continuity through proper synchronization between cells.
Data Source
AI summary
The present application discloses a dynamic sub-frame configuration method in the TDD system. The method includes: in the case that the uplink and downlink sub-frame configuration of a cell and the uplink and downlink sub-frame configuration of its neighboring cell are different in the configuration of a sub-frame, a part of resources on the sub-frame are made to be silent for the cell, and the resources on the sub-frame corresponding to the resources not silenced on the sub-frame for cell are made to be silent for the neighboring cell; or, a part of resources on the sub-frame are made to be silent for the neighboring cell, and the resources on the sub-frame corresponding to the resources not silenced on the sub-frame for the neighboring cell are made to be silent for the cell. The present application further provides a dynamic sub-frame configuration apparatus in the TDD system. Not only can the problem that inter-cell interference is introduced during sub-frame switching in the TDD system be solved, but also the normal uplink and downlink measurement can be guaranteed, without affecting ACK/NACK feedback and HARQ process, and meantime the frequency spectrum utilization ratio is increased.