D2D Synchronization in Unlicensed Bands via Carrier Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Device-to-Device (D2D) communication in unlicensed frequency bands faces challenges in synchronization due to the absence of a Global Positioning System (GPS) and coexistence with legacy devices operating under different communication standards, leading to difficulties in channel access and reduced throughput.
Innovation Solution
A method and apparatus for D2D synchronization that involves transmitting a synchronization signal during a preset period, determining signal detection, and configuring a time period for D2D communication only when no interference is detected, allowing D2D devices to synchronize and communicate while avoiding conflicts with legacy devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If D2D devices perform synchronization in unlicensed frequency bands, then channel access and communication can be established, but interference with legacy devices occurs and throughput is reduced
Solution Approach 1:
The patent applies preliminary action by performing synchronization before actual data communication. Devices first exchange synchronization signals to establish time alignment, then proceed to data transmission only after confirming no legacy devices are present. This preliminary synchronization step enables subsequent efficient D2D communication while avoiding interference with legacy devices.
Solution Approach 2:
The patent uses synchronization signals as an intermediary mechanism to coordinate between D2D devices and legacy devices. These special signals allow D2D devices to detect the presence of legacy devices and adjust their synchronization timing accordingly, acting as a mediator that prevents direct interference while enabling D2D communication.
2Reliability
If D2D devices continuously perform synchronization, then synchronization accuracy is maintained, but power consumption increases
Solution Approach 1:
The patent implements periodic action by having devices perform synchronization at specific intervals rather than continuously. Synchronization occurs periodically before data transmission and can be resumed after interruptions, reducing power consumption while maintaining adequate synchronization accuracy for reliable communication.
Solution Approach 2:
The patent applies self-service through carrier sensing mechanisms where devices autonomously detect the presence of legacy devices and adjust synchronization behavior accordingly. When no legacy devices are detected, devices can maintain synchronization with reduced power consumption; when legacy devices are present, synchronization is temporarily suspended or adjusted.
3Measurement precision
If D2D devices use GPS for synchronization, then synchronization accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the GPS dependency from the synchronization mechanism. Instead of requiring each D2D device to have its own GPS receiver, the system uses peer-to-peer synchronization where devices exchange timing information directly. This removes the complex GPS hardware requirement while maintaining synchronization accuracy through distributed timing coordination.
Solution Approach 2:
The patent creates a universal synchronization mechanism that works for all D2D devices regardless of whether they have GPS capability. The same synchronization protocol can be used by devices with or without GPS, making the system universally applicable and reducing overall device complexity by eliminating the need for GPS hardware in all devices.
Data Source
AI summary
A method and an apparatus for synchronization for Device-to-Device (D2D) communication in unlicensed frequency bands are provided. The method includes determining whether a signal is detected during a preset time period within a synchronization period, after transmitting a synchronization signal during the synchronization period for the D2D communication, when it is determined that the D2D communication is to be performed, and starting the time period for the D2D communication and performing the D2D communication during the time period for the D2D communication, when it is determined that the signal is not detected.