HARQ Retransmission in D2D Communication via Base Station Coordination
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Solution Overview
Problem
Existing HARQ mechanisms are limited to communication between a base station and a single mobile device, making it challenging to maintain communication quality when switching from uplink/downlink communication to device-to-device (D2D) communication between two mobile devices.
Innovation Solution
A method for performing hybrid automatic repeat request (HARQ) retransmission in D2D communication, where a base station allocates wireless resources and transmits resource allocation messages to both D2D communication transmitter and receiver, allowing them to realize HARQ through feedback packets, thereby maintaining communication quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ mechanism is extended to D2D communication between two mobile devices, then communication quality and reliability are improved, but system complexity and resource management difficulty increase
Solution Approach 1:
The base station serves as an intermediary that coordinates HARQ operations between D2D devices. It receives feedback from the receiving device, determines retransmission necessity, and manages resource allocation, thereby enabling reliable HARQ functionality without requiring complex peer-to-peer coordination between mobile devices
Solution Approach 2:
The receiving device sends feedback information to the base station regarding successful or unsuccessful data reception. The base station uses this feedback to control retransmission operations, implementing a feedback-based error correction mechanism that improves communication reliability while keeping device complexity manageable
2Reliability
If base station coordinates HARQ feedback and retransmission for D2D communication, then data transmission reliability is improved, but network load and signaling overhead increase
Solution Approach 1:
The base station combines multiple functions into a single coordination entity: it manages resource allocation for D2D communication, collects HARQ feedback from receiving devices, and controls retransmission operations. This merging approach consolidates signaling overhead and network load into the base station rather than distributing it across multiple devices
Solution Approach 2:
The receiving device autonomously generates HARQ feedback based on its own reception status, and the base station autonomously decides whether to trigger retransmission based on received feedback. This self-service approach minimizes unnecessary signaling and reduces overall network load by avoiding redundant coordination messages
Data Source
AI summary
A method for performing hybrid automatic repeat request (HARQ), a base station (BS), and a mobile device are provided. In the method, a wireless resource is allocated by the BS, and whether to perform a device-to-device (D2D) communication is determined. When the D2D communication is performed, a first resource allocation message is transmitted by the BS to a first mobile device and a second mobile device, and the first mobile device, working as a transmitter, transmits a data packet to the second mobile device, working as a receiver, according to the first resource allocation message. A HARQ feedback packet is received by the BS from the second mobile device to determine whether the data packet is successfully transmitted. When the HARQ feedback packet is a negative acknowledgement (NACK), the BS retains the original wireless resource or transmits a second resource allocation message to the first and the second mobile devices.