Non-Adaptive HARQ Retransmission on SPS Resources
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in non-adaptive Hybrid Automatic Repeat Request (HARQ) retransmissions using semi-persistent scheduling (SPS) resources, leading to increased PDCCH load and errors due to UL grant skipping, which results in inefficient resource utilization and erroneous decision-making by the eNB.
Innovation Solution
Enabling non-adaptive HARQ retransmissions on configured UL resources, such as SPS resources, through configuration options like always allowing retransmissions, allowing based on conditions, using boolean or threshold parameters, or system information broadcasts, to prioritize retransmissions and reduce PDCCH overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If non-adaptive HARQ retransmissions are performed on SPS resources without explicit grants, then PDCCH overhead is reduced, but resource utilization efficiency deteriorates due to UL grant skipping errors
Solution Approach 1:
The system performs preliminary configuration of SPS resources and establishes predetermined rules for non-adaptive retransmissions before actual data transmission occurs. The eNB and UE agree in advance on SPS parameters, HARQ process IDs, and retransmission behaviors, eliminating the need for dynamic PDCCH grants during retransmissions and preventing UL grant skipping errors through pre-coordinated resource allocation
Solution Approach 2:
The patent uses the originally granted SPS resource parameters (frequency, time, resource blocks) as templates for retransmissions. Instead of creating new dynamic grants, the system copies and reuses the pre-configured SPS resource allocation for HARQ retransmissions, maintaining resource efficiency while avoiding PDCCH overhead associated with adaptive scheduling
2Productivity
If non-adaptive retransmissions are enabled on SPS resources, then resource utilization improves, but system complexity increases due to configuration management
Solution Approach 1:
The SPS configuration mechanism serves multiple functions simultaneously: it allocates initial uplink resources, defines retransmission parameters, establishes HARQ process behavior, and sets resource allocation patterns. This multi-functionality reduces the need for separate configuration mechanisms and simplifies overall system management despite the enhanced capabilities
Solution Approach 2:
The system manages complexity by controlling specific parameters of non-adaptive retransmissions through SPS configuration, such as transport block size, redundancy versions, and HARQ process IDs. By carefully selecting and constraining these parameters within predefined ranges and relationships, the system achieves flexible resource utilization without overwhelming configuration complexity
Data Source
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AI summary
Techniques, apparatus and methods are disclosed that enable non-adaptive Hybrid Automatic Repeat Request (HARQ) retransmission using SPS resources. Non-adaptive HARQ retransmission can be enabled in a configured Uplink (UL) resource (such as SPS resources). As it may not be beneficial to allow non-adaptive HARQ retransmission on SPS resources for all kinds of traffic, options for proper configuration can be provided either by network signaling or by predefined configurations. For example, six potential embodiments are described to enable non-adaptive retransmission using SPS resources: (1) Always allow non-adaptive retransmission on configured UL grants; (2) Allow non-adaptive retransmission on configured UL grants only for certain predefined conditions; (3) Allow non-adaptive HARQ retransmissions when there is no data in the UL buffer for new transmission; (4) Enable non-adaptive retransmissions using a configurable boolean parameter; (5) Enable non-adaptive retransmissions using a configurable threshold parameter; and (6) Enable non- adaptive retransmissions using a configuration sent using a system information broadcast.