SPS HARQ Retransmission Resource Allocation for URLLC Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication technologies face challenges in achieving ultra-reliable low latency hybrid automatic repeat request (HARQ) retransmissions for semi-persistent scheduling (SPS) due to limitations in resource allocation and adaptability, which hinder the attainment of target reliability and latency requirements in ultra-reliable low latency communication (URLLC) scenarios.
Innovation Solution
Configuring hybrid automatic repeat request (HARQ) retransmission resources on Physical Downlink Shared Channel (PDSCH) / Physical Uplink Shared Channel (PUSCH) to meet threshold reliability within latency bounds by using adaptive resource allocation and synchronous HARQ processes, ensuring reliable communication in URLLC environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adaptive resource allocation and synchronous HARQ processes are used for SPS, then reliability and latency requirements are met, but resource allocation complexity increases
Solution Approach 1:
The patent implements dynamic resource allocation for HARQ retransmissions in SPS, where resource blocks are adaptively assigned based on channel conditions and retransmission requirements. The system dynamically adjusts resource allocation parameters including time-frequency resource selection, modulation and coding schemes, and power levels to meet reliability targets while managing complexity through structured adaptation rules.
Solution Approach 2:
The system changes multiple transmission parameters simultaneously to achieve target reliability: it adjusts resource block allocation, modifies modulation schemes (QPSK, 16QAM, etc.), changes coding rates, and adapts power levels. These parameter changes are coordinated through the HARQ process to ensure that reliability requirements are met while the systematic approach manages the overall complexity.
2Reliability
If resource allocation is optimized for reliability, then communication reliability improves, but system adaptability to varying traffic patterns decreases
Solution Approach 1:
The patent employs dynamic resource allocation that adapts to varying traffic patterns while maintaining reliability. The system monitors traffic characteristics and channel conditions, then dynamically adjusts resource block assignments, time-frequency allocations, and transmission parameters. This dynamic adaptation allows the system to handle different traffic patterns (e.g., bursty vs. steady traffic) while ensuring target reliability is met through coordinated parameter adjustment.
Solution Approach 2:
The system segments resource allocation into multiple controllable dimensions: time resources (slots, subframes), frequency resources (resource blocks), and spatial resources (antenna ports, beams). Each dimension can be independently optimized for reliability while collectively adapting to traffic patterns. The HARQ process operates independently within this segmented resource framework, allowing flexible adaptation without compromising reliability guarantees.
3Loss of time
If synchronous HARQ processes are used, then latency is reduced, but flexibility in resource allocation is limited
Solution Approach 1:
The patent implements synchronous HARQ processes with dynamic resource allocation within the synchronous framework. The synchronous nature ensures fixed timing relationships that reduce latency, while dynamic adjustment of resource blocks, modulation schemes, and power levels within each synchronous cycle provides flexibility. The system dynamically selects resources and parameters for each transmission and retransmission while maintaining the synchronous timing structure, thus achieving low latency with retained adaptability.
Solution Approach 2:
The system performs preliminary configuration of HARQ processes with predetermined timing relationships and resource patterns that enable synchronous operation. These preliminary configurations establish the low-latency synchronous framework, while allowing dynamic resource allocation within the pre-established timing structure. The preliminary action of setting up the synchronous framework enables subsequent flexible resource adjustments without breaking the latency-reducing synchronous timing.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a configuration for hybrid automatic repeat request (HARQ) retransmissions for semi-persistent scheduling (SPS), wherein the configuration, which is specific to the UE, identifies allocated resources of a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH) for the HARQ retransmissions; and use the allocated resources identified in the configuration for the HARQ retransmissions. Numerous other aspects are provided.