D2D Signal Transmission via Carrier Sensing in Unlicensed Bands
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently transmitting device-to-device direct communication signals, particularly in unlicensed bands, due to interference and power consumption issues.
Innovation Solution
A method involving configuring a resource pool of units for D2D signal transmission, determining the number of transmission attempts, and selecting idle resource units for transmission, while performing carrier sensing to avoid busy states, thereby optimizing transmission probability and minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If D2D signal transmission is performed in unlicensed bands, then spectrum utilization is improved, but interference with other systems increases
Solution Approach 1:
The patent applies preliminary action by performing carrier sensing (Listen-Before-Talk) before D2D signal transmission in unlicensed bands. The transmitting UE senses the channel to detect whether it is occupied by other systems (e.g., Wi-Fi) and only proceeds with transmission when the channel is clear. This advance detection prevents interference with other systems while enabling spectrum utilization, directly resolving the technical contradiction.
2Reliability
If multiple transmission attempts are made to ensure reliable D2D communication, then reliability is improved, but power consumption increases
Solution Approach 1:
The patent applies dynamics by making the number of transmission attempts adaptive rather than fixed. The transmitting UE dynamically adjusts the number of retransmission attempts based on whether carrier sensing succeeds or fails. When the channel is clear, transmission proceeds; when blocked, the UE waits and retries. This dynamic adjustment ensures communication reliability while avoiding unnecessary power consumption from fixed multiple transmission attempts.
3Productivity
If resource pool is configured for D2D transmission, then transmission efficiency is improved, but resource allocation complexity increases
Solution Approach 1:
The patent applies self-service by enabling UEs to autonomously select resources from a pre-configured resource pool for D2D transmission without requiring complex centralized scheduling. Each UE independently performs carrier sensing and selects appropriate time-frequency resources from the pool, simplifying the resource allocation process while maintaining transmission efficiency. This self-service mechanism reduces resource allocation complexity compared to centralized scheduling approaches.
Data Source
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AI summary
Abstract: Disclosed is a method for transmitting a device to device (D2D) signal by a terminal in a wireless communication system. More particularly, the method for transmitting a D2D signal comprises the steps of: configuring a resource pool comprising a plurality of resource units for transmitting the D2D signal; determining the number of transmission attempts for the D2D signal; selecting as many resource units as the number of transmission attempts from among the resource units in the resource pool; and determining whether the selected resource units are in the busy state or in the idle state over time, and when it is determined that the selected resource units are in the idle state, transmitting the D2D signal to a target terminal.