D2D Communication Feedback Path Optimization via Velocity
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Solution Overview
Problem
Current D2D communication systems in cellular networks face challenges with robustness against fading, shadowing, and interference, particularly in terms of feedback mechanisms, which limits the reliability and efficiency of device-to-device communications.
Innovation Solution
A method and radio access network node that enable direct data transmission between wireless devices with adaptive feedback paths based on relative velocity calculations, ensuring efficient resource allocation and minimizing latency, while maintaining cellular system control over transmission parameters to reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If D2D communication uses direct transmission between devices, then spectral efficiency and energy efficiency are improved, but robustness against fading and interference deteriorates
Solution Approach 1:
The patent introduces the cellular infrastructure (base station) as an intermediary to provide feedback information to D2D devices. This mediator helps devices adapt their transmission parameters to combat fading and interference, thereby improving robustness while maintaining direct D2D transmission for spectral efficiency.
Solution Approach 2:
The patent implements feedback mechanisms where receiving devices send channel quality information back to transmitting devices through the cellular infrastructure. This feedback enables adaptive modulation and coding, allowing D2D communication to adjust to varying channel conditions and improve reliability against fading.
2Loss of time
If D2D communication uses direct transmission between devices, then latency is reduced, but control and interference management become more difficult
Solution Approach 1:
The cellular base station acts as a mediator that centralizes control functions for D2D communications. It manages resource allocation, monitors channel conditions, and coordinates transmissions, thereby simplifying control complexity while maintaining low latency through direct device-to-device data paths.
Solution Approach 2:
The patent segments control functions from data transmission functions. Control signaling and data transmission use separate channels and procedures, allowing independent optimization of each function while managing overall system complexity through modular architecture.
3Reliability
If feedback information is transmitted frequently to improve link adaptation, then transmission reliability is improved, but uplink resource consumption increases
Solution Approach 1:
The patent implements periodic feedback reporting where devices transmit channel quality information at predetermined intervals rather than continuously. This periodic action maintains adequate link adaptation accuracy while significantly reducing uplink resource consumption compared to continuous feedback.
Solution Approach 2:
The patent dynamically adjusts feedback reporting parameters such as reporting frequency and granularity based on channel conditions and service requirements. Under stable conditions, feedback is reduced to save resources; under rapidly changing conditions, feedback frequency increases to maintain reliability.
Data Source
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AI summary
In wireless device-to-device, D2D, communication data (D) are transmitted directly from a first wireless device (UE Tx) to a second wireless device (UE Rx). In response to the direct transmission of data (D), the second wireless device (UE Rx) transmits feedback data (FB1, FB2) indicating at least one quality of the data (D) received in the second wireless device (UE Rx). More precisely, according to the invention, a radio access network node (BS) controls the direct transmission of data (D) by means 10 of downlink control information (Ctrl1, Ctrl2) to the first and second wireless devices (UE Tx; UE Rx), and the feedback data (FB1, FB2) are received in the radio access network node (BS). The radio access network node (BS) preferably also uses the received feedback (FB1, FB2) to control at least one of the first and second wireless devices (UE Tx; UE Rx).