Sidelink Feedback Channel Resource Utilization
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Solution Overview
Problem
In wireless communication systems, particularly in 5G NR, there is a significant underutilization of resources allocated for sidelink HARQ feedback, leading to inefficiencies and overhead in sidelink communication, especially in scenarios like C-V2X, where substantial resources remain unused despite being allocated for HARQ ACK/NACK feedback.
Innovation Solution
The proposed solution involves configuring a UE to generate and transmit scheduling requests on resources allocated for feedback channels, allowing for more efficient use of sidelink communication resources by optimizing the allocation and utilization of physical sidelink feedback channels (PSFCH) through techniques such as Zadoff-Chu sequence transmissions and cyclic shifts, enabling the transmission of HARQ feedback and scheduling requests on the same resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resources are allocated for sidelink HARQ feedback on PSFCH, then feedback transmission capability is improved, but resource utilization deteriorates due to significant underutilization
Solution Approach 1:
The PSFCH resources are configured to carry both HARQ feedback (ACK/NACK) and scheduling requests. By making the feedback channel multi-functional, the patent resolves the contradiction between ensuring reliable feedback transmission and improving resource utilization efficiency. The same physical resources serve dual purposes: conveying acknowledgment information and carrying scheduling requests when needed.
Solution Approach 2:
The patent merges the scheduling request function with the HARQ feedback channel. Instead of having separate resources for scheduling requests and feedback, the invention combines these functions into the PSFCH, allowing UEs to transmit both types of information on the same channel, thereby eliminating resource waste while maintaining both capabilities.
2Reliability
If dedicated resources are allocated for scheduling requests, then request transmission reliability is improved, but overhead increases due to additional resource allocation
Solution Approach 1:
The PSFCH is designed to serve multiple functions: carrying HARQ feedback and transmitting scheduling requests. This multi-functionality eliminates the need for separate dedicated resources for scheduling requests, thereby reducing resource overhead while maintaining reliable request transmission through the established feedback channel infrastructure.
Solution Approach 2:
The invention combines scheduling request transmission with the existing HARQ feedback channel. By merging these functions, the patent avoids allocating additional dedicated resources for scheduling requests, thus reducing overall resource overhead while ensuring reliable request delivery through the proven PSFCH mechanism.
Data Source
AI summary
A first apparatus may be configured to generate a scheduling request to request to transmit at least one of data or control information on a sidelink channel. The first apparatus may be further configured to transmit, to another UE, the scheduling request on resources of a channel configured to carry feedback responsive to transmissions on the sidelink channel. A second apparatus may be configured to monitor resources on a channel for transmissions from other UE, the channel being configured to carry feedback from the other UE responsive to transmissions on a sidelink channel. The second apparatus may be further configured to receive at least one scheduling request from at least one of the other UE on the resources of the channel configured to carry the feedback based on monitoring the resources on the channel.