D2D Synchronization Signal Detection via OFDM Symbol Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In device-to-device (D2D) communication, existing wireless communication systems face challenges in efficiently acquiring synchronization between user equipment (UEs) due to inter-cell interference and the inefficiency of individual UEs matching synchronization signals, which can lead to interference and reduced network performance, especially in scenarios with partial network coverage or out-of-coverage UEs.
Innovation Solution
A method and apparatus for D2D synchronization in a wireless communication system, where user equipment detects a D2D synchronization signal comprising a primary and secondary synchronization signal from OFDM symbols, determining the application type or duplex mode based on the symbol structure, such as the arrangement and separation of these signals, to rapidly and stably obtain synchronization information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If individual UEs attempt to match synchronization signals independently, then each UE can autonomously acquire synchronization, but inter-cell interference increases and network performance deteriorates
Solution Approach 1:
The patent introduces a synchronization signal transmitting UE as an intermediary that broadcasts synchronization signals to other UEs. Instead of each UE independently searching for synchronization signals from base stations (which causes inter-cell interference), one UE acts as a mediator that has already acquired synchronization and shares it with others, thereby reducing interference while maintaining autonomous synchronization capability.
Solution Approach 2:
The patent segments the synchronization acquisition process into two stages: first, a designated UE acquires synchronization from the base station; second, this UE transmits the synchronization signal to other UEs. This segmentation divides the problematic simultaneous independent acquisition into a coordinated sequential process, reducing inter-cell interference while preserving autonomous operation.
2Productivity
If D2D communication is implemented without eNB intervention, then network overhead is reduced and device autonomy increases, but synchronization acquisition becomes more difficult
Solution Approach 1:
The patent applies preliminary action by having the synchronization signal transmitting UE acquire synchronization from the base station beforehand before engaging in D2D communication. This pre-acquired synchronization is then shared with other UEs through dedicated synchronization signals, making the overall synchronization acquisition easier while maintaining the benefit of reduced network overhead.
Solution Approach 2:
The patent uses copying by having the synchronization signal transmitting UE replicate the synchronization information it acquired from the base station and transmit it to other UEs. Instead of each UE independently acquiring synchronization (which is difficult without eNB intervention), one UE copies the synchronization data and distributes it, reducing acquisition difficulty while maintaining D2D autonomy.
3Reliability
If synchronization signals are transmitted in all subframes, then synchronization availability is maximized, but power consumption and interference increase
Solution Approach 1:
The patent implements periodic action by transmitting synchronization signals only in specific subframes rather than continuously in all subframes. The synchronization signal transmitting UE sends signals at predetermined intervals according to a configured pattern, which maintains sufficient synchronization availability for D2D communication while significantly reducing power consumption compared to continuous transmission.
Data Source
AI summary
In one embodiment of the present invention, a method for acquiring device-to-device (D2D) synchronization by a terminal in a wireless communication system comprises the steps of: receiving a subframe; and detecting a D2D synchronization signal including a first synchronization signal and a second synchronization signal, from a plurality of orthogonal frequency division multiplexing (OFDM) signals of the subframe, wherein the terminal can determine a kind of an application related to the D2D synchronization signal from a symbol structure formed by an OFDM symbol through which the first synchronization signal is transmitted and an OFDM symbol through which the second synchronization signal is transmitted.