User Terminal D2D Group Identifier Transmission for Half-Duplex Scheduling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In D2D proximity services, user terminals face the Half-Duplex problem where they cannot transmit and receive D2D radio signals simultaneously, leading to reception failures when belonging to multiple D2D groups due to overlapping transmission timings.
Innovation Solution
User terminals transmit group identifiers to the base station before data transmission or as part of a buffer status report, allowing the base station to schedule D2D resources such that terminals in different groups can transmit at different times, preventing simultaneous transmissions and ensuring reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a user terminal belongs to multiple D2D groups and transmits D2D radio signals in each group, then the terminal can participate in multiple D2D communications, but the terminal cannot receive D2D radio signals from other groups at the same time due to the Half-Duplex problem
Solution Approach 1:
The base station performs preliminary scheduling by determining transmission timing for each user terminal in each D2D group before actual transmission occurs. The scheduling information is notified to terminals in advance, allowing them to know when to transmit and when to receive, thus avoiding the Half-Duplex conflict by pre-coordinating resource allocation across multiple groups.
2Reliability
If the base station assigns time and frequency resources to prevent simultaneous transmissions by multiple terminals in the same D2D group, then the Half-Duplex problem is solved within the group, but terminals still experience reception failures when transmitting in one group and receiving from another group at the same time
Solution Approach 1:
The base station acts as an intermediary that coordinates transmission timing across all D2D groups. It determines the transmission timing for each user terminal in each group and notifies the scheduling information to terminals, thereby mediating the resource allocation to avoid Half-Duplex conflicts not only within but also across different D2D groups.
3Stability of the object's composition
If a user terminal transmits D2D radio signals at the same timing in multiple D2D groups, then the terminal can maintain synchronization across groups, but other terminals in those groups cannot receive the signals due to the transmitting terminal being in Half-Duplex mode
Solution Approach 1:
The base station performs preliminary scheduling by determining transmission timing for each user terminal in each D2D group before actual transmission occurs. The scheduling information is notified to terminals in advance, allowing them to know when to transmit and when to receive, thus avoiding the Half-Duplex conflict by pre-coordinating resource allocation across multiple groups.
Data Source
AI summary
A user terminal according to the present embodiment comprises: a controller configured to perform control of transmitting at least one or more group identifiers among a plurality of group identifiers comprising of an identifier associated with each of a plurality of D2D groups in D2D communication being direct inter-terminal communication to a base station as an identifier of a destination of data in the D2D communication.