HARQ Mode Switching for Long-Delay Satellite Data Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The application of conventional HARQ technology in satellite communication results in prolonged waiting times for acknowledgment or negative acknowledgment, significantly reducing data transmission throughput due to the long distances and delays in satellite communication networks.
Innovation Solution
A method is provided to flexibly configure the HARQ process by using a first identifier to switch between HARQ transmission modes (HARQe and HARQd) without additional signaling, allowing for quick configuration and resource reuse, thereby improving data transmission throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HARQ transmission mode (HARQe) is used to ensure reliable data transmission with feedback, then data reliability is improved, but waiting time increases and throughput decreases
Solution Approach 1:
The patent applies dynamics by enabling the HARQ process to switch between two transmission modes (HARQe with feedback and HARQd without feedback) based on channel conditions and data characteristics. This dynamic adaptation allows the system to optimize between reliability and throughput depending on the current operational requirements, resolving the contradiction between these two parameters.
Solution Approach 2:
The patent changes the operational parameter of the HARQ process by introducing a switching mechanism that can transition between HARQe and HARQd modes. This parameter change enables flexible adjustment of the feedback mechanism, allowing the system to balance between ensuring data reliability and maintaining high throughput based on varying communication conditions.
2Reliability
If HARQ process waits for ACK/NACK feedback before new transmission, then data transmission reliability is ensured, but transmission efficiency decreases due to stop-and-wait protocol
Solution Approach 1:
The patent makes the HARQ process dynamic by allowing it to switch between feedback-based mode (HARQe) and non-feedback mode (HARQd). When transmission efficiency is prioritized and reliability requirements are met, the system can operate in HARQd mode to eliminate stop-and-wait delays, thereby improving transmission efficiency while maintaining acceptable reliability.
Solution Approach 2:
The patent enables continuous transmission by allowing the base station to send new data without waiting for ACK/NACK feedback when operating in HARQd mode. This continuity of useful action eliminates the stop-and-wait protocol's interruptions, significantly improving transmission efficiency while the system can switch to HARQe mode when reliability becomes the critical constraint.
3Adaptability or versatility
If additional signaling is added to configure HARQ process switching, then configuration flexibility is improved, but signaling overhead increases
Solution Approach 1:
The patent applies universality by making the first identifier serve multiple functions: it acts as both the traditional NDI (new data indicator) for identifying data type and as a control signal for switching between HARQe and HARQd modes. This multi-functionality enables configuration flexibility without requiring separate signaling bits, thereby avoiding additional signaling overhead.
Solution Approach 2:
The patent discards the need for separate HARQ mode indication signaling by reusing the existing first identifier (NDI) field. The system recovers the switching control function from the traditional NDI field, allowing the same bit to carry both data type information and mode switching information, thus avoiding additional signaling overhead while maintaining flexibility.
Data Source
AI summary
Embodiments of this application disclose a data transmission method, apparatus, and system, and relate to the communication field. This can flexibly configure a HARQ process to improve a data transmission throughput. A specific solution is: A network device sends a first transport block and a first identifier to a terminal. The first identifier is used to indicate whether to switch, from non-hybrid automatic repeat request HARQ transmission to HARQ transmission, a HARQ process in which the first transport block is located. The first identifier is occupied when the HARQ process uses the HARQ transmission. The terminal receives the first transport block and the first identifier from the network device. The first identifier is used to indicate whether to switch, from the non-hybrid automatic repeat request HARQ transmission to the HARQ transmission, the HARQ process in which the first transport block is located.