Group-Based HARQ Signaling for Cellular D2D Retransmissions
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Solution Overview
Problem
Current HARQ mechanisms in wireless cellular networks do not efficiently exploit UE grouping and D2D cooperation capabilities, leading to increased complexity and inefficiency in network communications.
Innovation Solution
A two-level terminal-group based HARQ signaling method is implemented, where UEs within a virtual multi-point node receive and re-broadcast data packets with a timer, and acknowledge successful decoding, enabling efficient retransmissions and reducing signaling overhead through network coding and distributed HARQ schemes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If current HARQ mechanisms are used without UE grouping, then the implementation is simpler, but the efficiency of exploiting D2D cooperation capabilities is reduced and signaling overhead increases
Solution Approach 1:
The patent segments the HARQ process into two levels: (1) BS-to-ViMP node level where the base station communicates with the virtual multi-point node, and (2) intra-ViMP node level where UEs within the ViMP node cooperate using D2D communications. This segmentation allows each level to handle specific tasks, improving efficiency while managing complexity through hierarchical organization.
Solution Approach 2:
The ViMP node acts as an intermediary between the BS and individual UEs. The ViMP node receives data packets from the BS, performs internal HARQ operations with member UEs, and manages retransmissions. This intermediary structure enables efficient exploitation of D2D cooperation capabilities while reducing the signaling burden on the BS.
2Productivity
If joint UE reception using D2D communications is implemented, then system throughput and coverage are improved, but the complexity of network communications such as HARQ signaling increases
Solution Approach 1:
Multiple UEs are merged into a single logical entity called a ViMP node. Within this ViMP node, UEs perform joint reception and cooperation using D2D communications. By merging UEs into a group, the system achieves improved throughput and coverage while managing complexity through the unified ViMP node structure rather than individual UE management.
Solution Approach 2:
The patent introduces a new dimension of communication by establishing D2D links between UEs within the same ViMP node. This creates an intra-node communication dimension in addition to the traditional BS-UE dimension, enabling joint reception and cooperation that improves system throughput and coverage.
3Reliability
If joint UE reception using D2D communications is implemented, then coverage is improved, but the complexity of network communications such as HARQ signaling increases
Solution Approach 1:
The HARQ process is segmented into hierarchical levels with the ViMP node managing internal cooperation tasks. This segmentation allows coverage extension through D2D cooperation while containing signaling complexity at the ViMP node level rather than propagating it to the BS for every individual UE interaction.
Solution Approach 2:
The ViMP node serves as an intermediary that handles complex D2D coordination and HARQ signaling internally. This intermediary structure enables coverage improvement through joint UE reception while shielding the broader network from the full complexity of intra-node communications.
Data Source
AI summary
System and method embodiments are provided to support network communications with groups of UEs. The embodiments include a two-level group-based hybrid-automatic repeat request (HARQ) mechanism and acknowledgement (ACK)/negative ACK (NACK) feedback. An embodiment method includes receiving, at a UE within a virtual multi-point (ViMP) comprising UEs, a data packet for a target UE (TUE) that is broadcasted from a base station (BS) to the ViMP node, decode the data packet, and upon successfully decoding the data packet, broadcasting the data packet to the UEs within the ViMP node until a timer pre-established by the BS expires or an ACK message is received from the TUE or the ViMP node. In an embodiment, broadcasted data received in the ViMP node is re-broadcasted upon receiving a negative acknowledgement (NACK) message from the TUE, a beacon UE, or any of the UEs within the ViMP node.