Adaptive HARQ Interlace Timing for Wireless Systems
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Solution Overview
Problem
Wireless mobile communication systems using HARQ face challenges in managing retransmission delays due to fixed correspondence relations between data transmission and feedback, which are not adaptable to varying data burst sizes and processing capabilities of base and mobile stations, leading to inefficiencies and increased complexity.
Innovation Solution
An adaptive Hybrid Automatic Repeat Request (HARQ) interlace method is introduced, where the retransmission timing is adjusted based on the number of subframes required for data burst transmission, allowing for flexible retransmission positions within frames, considering the processing capabilities of base and mobile stations, to optimize retransmission delays and reduce system overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fixed HARQ interlace is used with regular retransmission timing, then system overhead is reduced and latency is shortened, but the system cannot adapt to varying data burst sizes and processing capabilities of different nodes
Solution Approach 1:
The patent applies dynamics by making the HARQ interlace configurable and adaptable rather than fixed. The system dynamically adjusts the interlace parameters (k1, k2, k3) based on the specific service requirements, data burst sizes, and processing capabilities of base stations and mobile stations. This allows the same HARQ mechanism to serve multiple scenarios with different performance characteristics.
Solution Approach 2:
The patent changes the parameters of the HARQ interlace (specifically the timing offsets k1, k2, k3) to adapt to different service types and node capabilities. By modifying these temporal parameters, the system can optimize retransmission timing for various data burst lengths and processing speeds without changing the fundamental HARQ structure.
2Device complexity
If continuous allocation method is used with regular retransmission delay, then control message transmissions are reduced, but delay time varies with the ratio of DownLink to UpLink time slots
Solution Approach 1:
The patent addresses delay variation by introducing configurable timing parameters (k1, k2, k3) that adjust the relationship between DL and UL time slots. These parameters allow the system to compensate for delays caused by asymmetric DL/UL configurations while maintaining the continuous allocation method's benefit of reduced control overhead.
3Stability of the object's composition
If HARQ scheme with regular retransmission is implemented, then synchronous operation is achieved, but processing time requirements differ for nodes with different processing capabilities
Solution Approach 1:
The patent maintains synchronous HARQ operation stability while accommodating different processing capabilities by dynamically configuring the interlace parameters. Nodes with higher processing capabilities can use tighter timing (smaller k values), while nodes with lower capabilities can use more relaxed timing, all within the synchronous framework.
4Reliability
If fixed HARQ interlace timing is used, then retransmission timing is predictable, but flexibility in supporting various service states and channel conditions is limited
Solution Approach 1:
The patent enables the system to adapt to various service states and channel conditions by changing the HARQ interlace parameters. Different parameter sets can be selected based on channel quality, service requirements (e.g., latency-sensitive vs. throughput-oriented), and node capabilities, maintaining predictable timing within each configuration while offering flexibility across configurations.
Data Source
AI summary
An apparatus and method for controlling a Hybrid Automatic Repeat reQuest (HARQ) operation in a transmitter of a wireless mobile communication system using each frame constituted by a plurality of subframes are provided. In the method for controlling an HARQ operation, indication information indicating a subframe position where transmission of a data burst starts and the number of subframes required for transmission of the data burst is transmitted to a receiver through an i-th frame. When the number of subframes does not exceed a threshold, it is determined that the data burst at the subframe position indicated by indication information of an (i+1)-th frame is retransmitted to the receiver. When the number of subframes exceeds the threshold, it is determined that the data burst at the subframe position indicated by indication information of an (i+n)-th frame, where n is a positive integer exceeding 1, is retransmitted to the receiver.