Slot-Based Uplink Channel Design for Low-Latency HARQ
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems, particularly LTE, face challenges in improving mobile broadband access and reducing latency in uplink channels due to the limitations of legacy transmission time intervals (TTIs).
Innovation Solution
Implementing slot-based transmission time intervals (TTIs) for uplink channels, including Quick Physical Uplink Control Channels (QPUCCH), Quick Enhanced Physical Uplink Control Channels (QEPUCCH), and Quick Physical Uplink Shared Channels (QPUSCH), which allow for reduced latency by using a TTI of 0.5 ms and enabling frame scheduling of both legacy and Quick channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If legacy transmission time intervals (TTIs) are used in LTE uplink channels, then system stability and compatibility are maintained, but latency is increased and communication efficiency is reduced
Solution Approach 1:
The patent segments the uplink channel structure by introducing two distinct TTI types: legacy TTIs (subframe-based, 1ms) and Quick TTIs (slot-based, 0.5ms). This segmentation allows the system to handle different traffic requirements with appropriate TTI durations, reducing latency for time-sensitive applications while maintaining stability for常规 traffic through the legacy path.
Solution Approach 2:
The patent implements dynamic TTI selection where the system can adaptively choose between legacy and Quick TTIs based on traffic conditions, QoS requirements, and channel state. This dynamic approach enables the system to optimize latency performance when needed while maintaining compatibility with legacy operations, effectively managing the complexity-latency tradeoff.
2Productivity
If slot-based transmission time intervals (TTIs) are implemented for uplink channels, then latency is reduced and communication rates are enhanced, but system complexity increases due to frame scheduling of both legacy and Quick channels
Solution Approach 1:
The patent segments the frame structure into distinct regions for legacy and Quick channel transmissions. By allocating specific slots and resources separately for each channel type, the system manages complexity through structured organization rather than random integration, enabling efficient resource allocation while maintaining clear separation between legacy and enhanced operations.
Solution Approach 2:
The patent introduces a new dimension to the frame structure by overlaying Quick TTI transmissions within the existing legacy frame framework. This dimensional approach allows Quick channels to operate in slot-level granularity while legacy channels maintain subframe-level operations, enabling multi-rate communication without complete system redesign and managing complexity through hierarchical structuring.
3Loss of time
If Quick Physical Uplink Control Channels (QPUCCH) and Quick Enhanced Physical Uplink Control Channels (QEPUCCH) are used, then control information transmission latency is reduced, but resource allocation complexity increases
Solution Approach 1:
The patent merges the functionality of QPUCCH and QEPUCCH into a unified Quick uplink control channel framework. By combining these control channel types and their resource allocation mechanisms, the system reduces the complexity of managing separate control channel structures while maintaining the low-latency benefits of slot-based transmission for control information.
Data Source
AI summary
Certain aspects of the present disclosure provide techniques that may be used to help enable low latency communications between a user equipment (UE) and a base station (BS) using quick uplink channels that enable a reduced transmission time interval (TTI). An example method generally includes identifying a plurality of slots in a subframe, receiving a resource configuration for an uplink channel, wherein the resource configuration is associated with a first slot of the plurality of slots, determining a resource for transmitting the uplink channel in a second slot of the plurality of slots, wherein the resource is determined based on the resource configuration associated with the first slot of the plurality of slots, and transmitting the uplink channel in the second slot using the determined resource.