NR Sidelink HARQ Mode Selection for Retransmission Resources
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Solution Overview
Problem
There are challenges with Hybrid Automatic Repeat Request (HARQ) feedback in New Radio (NR) sidelink (SL) operations, particularly when NR Device-to-Device (D2D) transmissions are scheduled by a wireless network node via resource grants, leading to inefficiencies in resource allocation and communication reliability.
Innovation Solution
The proposed solution involves configuring user equipment (UE) with specific sidelink channels and hybrid ARQ feedback modes, and providing resource information that allows the UE to select resources and feedback modes that match the buffered data's requirements, including options for HARQ-enabled or HARQ-disabled physical sidelink feedback channel (PSFCH) resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ feedback is enabled in NR sidelink operations, then communication reliability is improved, but resource allocation complexity and overhead increase
Solution Approach 1:
The patent implements dynamic HARQ feedback mode selection where the UE can switch between HARQ-enabled and HARQ-disabled modes based on buffer status and channel conditions. The network node configures multiple resource pools with different HARQ settings, allowing the system to adapt resource allocation complexity to actual communication needs rather than using a fixed complex HARQ mechanism for all transmissions.
Solution Approach 2:
The patent changes the HARQ feedback parameter from a fixed state to a configurable state. The network node provides configuration information indicating different HARQ feedback modes for different resource pools, and the UE selects appropriate modes based on buffer status reports and channel conditions, thereby optimizing the balance between reliability and complexity.
2Adaptability or versatility
If multiple resource pools with different HARQ feedback modes are configured, then adaptability to different communication needs is improved, but device complexity increases
Solution Approach 1:
The patent segments the sidelink resources into multiple resource pools, each configured with specific HARQ feedback modes suitable for different communication scenarios. This segmentation allows the UE to select appropriate resources based on buffer status and service requirements without having to manage a single complex configuration for all scenarios.
Solution Approach 2:
The network node performs preliminary configuration of multiple resource pools with different HARQ settings before the UE needs to transmit. The configuration information is provided in advance, allowing the UE to quickly select pre-configured resources based on buffer status reports without performing complex real-time decisions about HARQ mode selection.
3Reliability
If HARQ feedback mechanisms are optimized for specific UE needs, then data transmission success rate is improved, but feedback mechanism complexity increases
Solution Approach 1:
The patent applies different HARQ feedback mechanisms locally to different resource pools based on specific communication needs. Each resource pool can have its own HARQ configuration (enabled or disabled), allowing the system to use simple or complex feedback mechanisms locally rather than applying a uniform complex mechanism system-wide.
Data Source
AI summary
Embodiments include methods, performed by a network node in a wireless network, for providing resources for device-to-device wireless communication between a first user equipment (UE) and a second UE. Such methods include transmitting, to the first UE, a configuration that identifies one or more sidelink (SL) channels between the first UE and the second UE, and one or more first hybrid ARQ (HARQ) feedback modes associated with the respective one or more SL channels. Such method also include transmitting, to the first UE, resource information identifying resources usable for communicating via the one or more SL channels Other embodiments include complementary methods by a first UE that include transmitting, to the second UE, buffered data for a particular SL channel using resources that are compatible with a first HARQ mode associated with the particular SL channel. Other embodiments include network nodes and UEs configured to perform such methods.