Hybrid HARQ Method for Mobile Communication Resource Allocation
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Solution Overview
Problem
In mobile communication systems, existing HARQ technologies face challenges in efficiently allocating resources, particularly in FDMA systems, where persistent and non-persistent traffic coexist, leading to inefficiencies in resource utilization and control signaling overhead.
Innovation Solution
The proposed HARQ method involves a hybrid approach that combines synchronous and asynchronous transmission strategies, allowing for efficient resource allocation by grouping retransmissions into spans and transmitting control information only when necessary, thereby minimizing resource waste and control channel usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If synchronous HARQ is used to minimize control information, then control channel overhead is reduced, but packet loss increases due to fixed retransmission timing regardless of channel conditions
Solution Approach 1:
The patent segments the HARQ approach into two parts: synchronous HARQ for initial transmission (to minimize control overhead) and asynchronous HARQ for retransmission (to improve reliability). This segmentation allows each part to operate with its optimal characteristics, resolving the contradiction between control information efficiency and packet reception reliability.
Solution Approach 2:
The patent introduces dynamic selection between synchronous and asynchronous HARQ modes based on channel conditions. When channel conditions are good, synchronous HARQ is used; when conditions deteriorate, asynchronous HARQ with adaptive retransmission timing is activated. This dynamic adaptation resolves the contradiction by allowing the system to switch between the two approaches optimally.
2Reliability
If asynchronous HARQ is used to adapt to channel conditions, then packet reception reliability improves, but control information overhead increases due to additional control signaling
Solution Approach 1:
The patent segments the HARQ approach into two parts: synchronous HARQ for initial transmission (to minimize control information) and asynchronous HARQ for retransmission (to improve reliability). This segmentation allows each part to operate with its optimal characteristics, resolving the contradiction between control information efficiency and packet reception reliability.
Solution Approach 2:
The patent applies different HARQ qualities to different transmission stages: synchronous HARQ (simpler, less control overhead) for initial transmission and asynchronous HARQ (more robust, adaptive) for retransmission. This local differentiation allows the system to achieve high reliability where needed while minimizing control overhead where possible.
3Productivity
If resources are allocated for persistent traffic, then resource allocation efficiency improves, but resource waste occurs when retransmissions are needed but resources are unavailable
Solution Approach 1:
The patent introduces dynamic resource allocation for retransmissions, allowing the system to flexibly allocate resources based on actual channel conditions and traffic needs. This dynamic approach ensures that resources are available when needed for retransmissions while maintaining high allocation efficiency during normal operations, resolving the contradiction between efficiency and resource waste.
Solution Approach 2:
The patent implements feedback mechanisms that monitor channel conditions and resource availability, enabling the system to adjust resource allocation for retransmissions in real-time. This feedback-driven approach prevents resource waste by ensuring retransmissions only occur when resources are available and channel conditions warrant them, while maintaining high overall allocation efficiency.
4Adaptability or versatility
If control information is transmitted with every subpacket, then channel adaptation capability improves, but device complexity increases
Solution Approach 1:
The patent segments control information transmission to occur only at the beginning of each span (not with every subpacket), reducing the frequency of control information processing while maintaining channel adaptation capability through the span-based structure. This segmentation resolves the contradiction by reducing device complexity without completely sacrificing adaptability.
Solution Approach 2:
The patent implements periodic control information transmission at span boundaries rather than continuous transmission with every subpacket. This periodic approach reduces the overall control information processing load and device complexity while maintaining adequate channel adaptation capability through regular updates at appropriate intervals.
Data Source
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AI summary
A Hybrid Automatic Repeat reQuest (HARQ) method performed in a receiver of a mobile communication system. The HARQ method includes receiving from a transmitter an initial transmission subpacket among a plurality of subpackets; sending a request for transmission of a retransmission subpacket to the transmitter upon failure to decode the initial transmission subpacket; receiving the retransmission subpacket using control information previously received from the transmitter upon failure to receive, from the transmitter, control information for reception of the retransmission subpacket; and receiving the retransmission subpacket using currently received control information upon receipt of the control information from the transmitter.