HARQ Identifier Determination for Multi-Slot Transmission Blocks
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Solution Overview
Problem
Current HARQ operation for multiple-slot transmission blocks in wireless communications faces challenges in determining the HARQ process ID and configuring timers, particularly when multiple slots span a system frame number border or when the start symbol is different across slots, leading to ambiguity in timer initialization and reinitialization.
Innovation Solution
The method involves determining the HARQ identifier based on a predetermined slot within the multiple-slot transmission block, such as the first or last slot, and configuring timers to start at the beginning of the first symbol of this slot, ensuring consistent and unambiguous HARQ operation across multiple slots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple slots are used for TB transmission to increase total power and reduce CRC overhead, then transmission reliability is improved, but ambiguity arises in HARQ ID determination and timer configuration when slots span system frame number borders or have different start symbols
Solution Approach 1:
The patent segments the multiple-slot TB transmission by identifying a specific reference slot (first slot or last slot) within the multi-slot transmission. This segmentation allows the system to apply single-slot HARQ ID determination rules to a specific reference point within the multi-slot transmission, thereby resolving the ambiguity while maintaining the reliability benefits of multi-slot transmission.
Solution Approach 2:
Instead of attempting to determine HARQ ID based on the entire multi-slot transmission or each individual slot, the patent inverts the approach by selecting a specific reference slot (either the first or last slot) and determining the HARQ ID based solely on that reference slot. This inversion simplifies the HARQ operation by reducing the multi-slot problem to a single-slot problem at a defined reference point.
2Reliability
If timers are configured to start at the beginning of the first symbol of each slot, then timer configuration becomes complex and ambiguous when slots have different start symbols, but consistent timing is required for HARQ operation
Solution Approach 1:
The patent segments the timer configuration problem by associating the timer start time with a specific reference slot rather than attempting to synchronize timers across all slots. This segmentation allows the timer to be configured unambiguously at the reference slot while the multi-slot transmission proceeds with potentially different start symbols.
Solution Approach 2:
The patent performs preliminary action by determining the reference slot (first or last slot) before configuring the timer. This preliminary identification of the reference slot establishes a clear, unambiguous starting point for timer configuration, eliminating the need for complex synchronization logic across multiple slots with different start symbols.
Data Source
AI summary
According to some embodiments, a method performed by a wireless device comprises preparing a multiple-slot transport block (TB) for transmission, determining a hybrid automatic repeat request (HARQ) identifier for the TB based on a slot associated with the multiple-slot TB, and transmitting the multiple-slot TB using a HARQ process associated with the determined HARQ identifier. In some embodiments, a method comprises determining a time to start or restart a timer based on a slot associated with the multiple-slot TB and transmitting the multiple-slot TB and starting or restarting the timer at the determined time.