Sidelink Feedback Transmission via Downlink Resources
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Solution Overview
Problem
Current device-to-device (D2D) communication systems lack reliable feedback mechanisms, leading to increased latency and reduced reliability due to the absence of channel state information feedback, especially in applications requiring ultra-low latency and real-time interaction like eV2X and smart factories.
Innovation Solution
A method and apparatus for transmitting feedback information in sidelink communication using downlink resources allocated by the base station, allowing receiving D2D terminals to inform transmitting terminals about data reception status without explicit scheduling requests, thereby reducing latency and enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If D2D communication uses traditional HARQ operation without feedback transmission, then device complexity is reduced, but reliability and latency performance deteriorate
Solution Approach 1:
The patent introduces HARQ feedback transmission in D2D communication where the receiving terminal sends ACK/NACK feedback to the transmitting terminal. This feedback mechanism enables the transmitting terminal to retransmit data when NACK is received, significantly improving data reception reliability while maintaining manageable system complexity through standardized feedback protocols
2Reliability
If D2D communication transmits data through base station (two-stage transmission), then reliability is improved, but latency increases
Solution Approach 1:
The patent extracts the data transmission path from the base station relay and enables direct D2D communication. The base station is removed from the data path, allowing terminals to communicate directly over the air interface. This extraction reduces transmission latency while maintaining reliability through introduced feedback and retransmission mechanisms
3Use of energy by moving object
If D2D communication uses short transmission distance, then power efficiency is improved, but adaptability to fast link changes deteriorates
Solution Approach 1:
The patent introduces channel state information feedback and HARQ feedback in D2D communication. The receiving terminal feeds back channel quality metrics and data reception status to the transmitting terminal, enabling dynamic adaptation to fast link changes. This feedback mechanism allows the system to adjust transmission parameters in real-time, improving adaptability while maintaining power efficiency through direct short-range communication
Data Source
AI summary
A device-to-device (D2D) communication method, performed by a receiving D2D terminal, may comprise receiving D2D data from a transmitting D2D terminal; generating feedback information for the D2D data; and receiving information on a first resource for transmission of the feedback information from a base station, and transmitting the feedback information to the transmitting D2D terminal through the first resource, wherein the information on the first resource is received without an explicit scheduling request (SR) to the base station.