Sidelink Retransmission Using Binned ACK/NACK Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, particularly in 5G NR, the existing acknowledgment (ACK)/negative acknowledgment (NACK) protocols for sidelink communications are resource-intensive due to the need for significant signaling and retransmissions, which can be inefficient in multi-device scenarios.
Innovation Solution
Implementing network coding (NC) with binned feedback mechanisms, where user equipment (UEs) transmit ACK/NACK on shared physical sidelink feedback channel (PSFCH) resources based on bins, allowing the NC encoding device to determine the status for each bin and select transport blocks for retransmissions efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional ACK/NACK protocols are used for sidelink communications, then reliable transmission confirmation is achieved, but resource consumption increases significantly due to individual feedback signaling for each UE
Solution Approach 1:
Multiple UEs are grouped into bins, and ACK/NACK feedback from multiple UEs is merged into shared PSFCH resources. The NC encoding device receives combined feedback signals from multiple UEs simultaneously, reducing the total number of feedback transmissions required while maintaining reliable transmission confirmation for each UE.
Solution Approach 2:
The shared PSFCH resources serve multiple UEs simultaneously, allowing a single feedback resource to perform the function of confirming receipt for multiple transport blocks from multiple UEs. This multi-functional approach reduces resource consumption while maintaining reliability.
2Measurement precision
If individual PSFCH resources are allocated to each UE for feedback, then feedback accuracy is maintained, but system capacity is reduced due to increased signaling overhead
Solution Approach 1:
Feedback from multiple UEs is combined in shared PSFCH resources, reducing signaling overhead and increasing system capacity. The NC encoding device processes these combined feedback signals to determine which transport blocks require retransmission, maintaining feedback accuracy while improving overall system productivity.
Solution Approach 2:
The NC encoding device acts as an intermediary that receives combined feedback from multiple UEs, processes this information, and determines retransmission requirements. This intermediary processing enables accurate feedback interpretation while reducing the signaling burden on individual UEs.
3Loss of energy
If network coding is implemented with binned feedback, then resource utilization for retransmissions is reduced, but feedback mechanism complexity increases
Solution Approach 1:
UEs are segmented into different bins based on their feedback requirements. This segmentation allows the system to manage complexity by organizing UEs into manageable groups, where each bin can be processed independently by the NC encoding device, reducing overall system complexity while maintaining resource efficiency.
Solution Approach 2:
The feedback mechanism uses parameter changes in the shared PSFCH resources to encode feedback information from multiple UEs. By changing parameters such as resource selection, timing, or signal characteristics, the system conveys complex feedback information efficiently without requiring proportionally complex processing infrastructure.
Data Source
AI summary
This disclosure provides systems, methods and apparatus, including computer storage media, for retransmission of sidelink transmissions using network coding with binned feedback. A transmitting device transmits a transport block and a request for a network coding (NC) encoding device to retransmit the transport block to a plurality of user equipment (UEs). The UEs decode the transport block and report an acknowledgment (ACK) or negative acknowledgment (NACK) on a physical sidelink feedback channel (PSFCH) resource associated with a bin for the UEs. The NC encoding device decodes the PSFCH resource for each bin to determine an ACK or NACK status for each bin, and determines whether to encode the transport block in a NC combination packet. The UEs receive the NC combination packet including an encoding of a subset of transport blocks. The receiving devices transmit an ACK or NACK on a PSFCH resource for a bin for each transport block.