Parallel HARQ Processes for Delay-Limited Coverage Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current communication technologies, particularly in LTE networks, face challenges in providing adequate coverage for delay-limited services such as VoIP and machine type communications due to limitations in transmission time interval bundling, which lengthens retransmission cycles and imposes constraints on service performance.
Innovation Solution
The solution involves dynamically allocating parallel hybrid automatic repeat request (HARQ) processes to transmit and decode transport blocks with data payload replicas across multiple HARQ processes, allowing for improved coverage by combining and decoding data packets within constrained delay limits, thereby enhancing service reliability and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If TTI bundling is used to improve coverage, then coverage area is improved, but retransmission cycle length increases causing delay constraints to be violated
Solution Approach 1:
The patent segments the single HARQ process into multiple parallel HARQ processes (e.g., 2, 4, or 8 processes). Each process handles a portion of the transport blocks independently, allowing simultaneous processing and reducing the overall retransmission cycle duration while maintaining coverage extension capabilities through spatial diversity.
2Loss of time
If multiple parallel HARQ processes are used to reduce latency, then retransmission cycle is shortened, but system complexity increases
Solution Approach 1:
The patent makes the HARQ system multi-functional by enabling dynamic configuration of the number of parallel HARQ processes based on service requirements. The same HARQ infrastructure can adaptively support different numbers of parallel processes (e.g., 2 for low complexity, 8 for low latency), providing universal coverage for various service types without requiring separate dedicated systems.
3Reliability
If transport blocks are combined across parallel HARQ processes, then decoding reliability is improved, but processing overhead increases
Solution Approach 1:
The patent implements partial combining by selectively combining transport blocks across parallel HARQ processes based on decoding outcomes. Instead of always combining all blocks from all processes, the system combines only when necessary (e.g., when initial decoding fails), reducing unnecessary processing overhead while maintaining reliability improvements where needed.
Data Source
AI summary
Various methods are described coverage enhancement of delay limited services according to an example embodiment. One example method may comprise generating one or more transport blocks. In some example embodiments, the transport blocks are configured to contain a data payload replica. The method of this embodiment may also include causing the one or more transport blocks to be transmitted via parallel hybrid automatic repeat request (HARQ) processes. In some example embodiments, the one or more transport blocks are transmitted based on a limited number of transmissions. The method of this embodiment may also include causing transmission of the one or more transport blocks in an instance in which an allocation does not include a new data indicator and which includes a same transport block size and transport block format for the data payload replica.