Selective TTI Bundling Configuration for Wireless Signaling
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Solution Overview
Problem
Current TTI bundling methods in wireless communication systems, such as LTE, face inefficiencies due to high overhead in Layer 1 and Layer 2 segmentation for VoIP packets, significant resource consumption for HARQ transmissions, and high packet loss probabilities, particularly in VoIP traffic.
Innovation Solution
The method involves selective TTI bundling configuration, enabling TTI bundling only for specific UL-SCH transmissions and HARQ processes, reducing overhead and resource usage by treating a TTI bundle as a single resource with a single uplink grant and HARQ acknowledgement, and optimizing HARQ timing and redundancy versions based on TTI bundling parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If TTI bundling is applied to all UL-SCH transmissions, then coverage enhancement is improved, but overhead from Layer 1 and Layer 2 segmentation increases significantly
Solution Approach 1:
The patent applies TTI bundling selectively only to specific UL-SCH transmissions and HARQ processes rather than universally. The base station configures TTI bundling parameters (tti-BundlingConfig) that indicate which transmissions should use bundling, allowing coverage enhancement to be applied locally where needed while avoiding overhead in transmissions that don't require it.
2Reliability
If TTI bundling is enabled for all HARQ processes, then packet loss probability is reduced, but resource consumption increases
Solution Approach 1:
The patent enables dynamic configuration of TTI bundling on a per-HARQ-process basis. The base station can activate or deactivate TTI bundling for specific HARQ processes through RRC signaling and DCI formats, allowing the system to adapt resource consumption to actual channel conditions and traffic requirements rather than statically enabling bundling for all processes.
3Adaptability or versatility
If Layer 1 and Layer 2 segmentation is used for VoIP packets, then transmission flexibility is improved, but overhead increases significantly
Solution Approach 1:
The patent extracts the segmentation function from the TTI bundling mechanism itself. Instead of requiring Layer 1 and Layer 2 segmentation within bundled TTIs, the system uses MAC layer segmentation combined with TTI bundling at the physical layer. This separation removes the redundant segmentation overhead while preserving transmission flexibility through MAC segmentation.
4Reliability
If multiple uplink grants are used for HARQ transmissions, then transmission reliability is improved, but signaling overhead increases
Solution Approach 1:
The patent merges multiple uplink grants into a single grant for TTI-bundled transmissions. The base station configures a single uplink grant that covers the entire TTI bundle (multiple consecutive subframes), eliminating the need for separate grants for each transmission within the bundle. This reduces PDCCH signaling overhead while maintaining reliability through the bundled transmissions.
Data Source
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AI summary
A method for determining transmission time interval (TTI) bundling parameters on a wireless communication device is described. The method includes receiving signaling that indicates a TTI bundling configuration. The method also includes receiving signaling that indicates an uplink grant. The method further includes determining at least one TTI bundling parameter based on the TTI bundling configuration and the uplink grant. The method additionally includes transmitting a signal based on the at least one TTI bundling parameter.