HARQ Process Handling at Extremely Large Subcarrier Spacing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems, particularly in 5G and expected 6G, face limitations in handling a large number of hybrid automatic repeat request (HARQ) processes due to increased subcarrier spacing, leading to inefficiencies in downlink control information (DCI) size and latency issues, especially at extremely large subcarrier spacings like 1920 kHz, where thousands of HARQ processes are required within a second.
Innovation Solution
The proposed solution involves configuring the DCI to support thousands of HARQ processes by increasing its size, potentially by 6 bits, and dynamically allocating HARQ process numbers without including HARQ IDs, allowing for flexible configuration based on traffic requirements and resource mapping, which reduces DCI size and improves latency by eliminating unnecessary bits and optimizing resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If DCI size is increased to support thousands of HARQ processes at extremely large SCS, then the number of supported HARQ processes increases, but DCI overhead and resource consumption increase
Solution Approach 1:
The patent segments HARQ process handling into two parts: (1) DCI carries only essential scheduling information with reduced overhead, and (2) HARQ process identification is derived from resource mapping parameters (slot index, PRB index, RBG index) rather than explicitly signaled. This segmentation allows supporting thousands of HARQ processes without proportionally increasing DCI size.
Solution Approach 2:
The patent introduces resource mapping parameters (slot index, physical resource block index, resource block group index) as intermediaries to indirectly identify HARQ processes. Instead of directly signaling HARQ process IDs in DCI, the system uses these resource parameters that naturally map to specific HARQ processes, reducing DCI overhead while maintaining process identification capability.
2Measurement precision
If DCI includes HARQ ID bits to distinguish between many HARQ processes, then HARQ process identification capability improves, but DCI size and control resource requirements increase
Solution Approach 1:
The patent extracts the HARQ ID field from DCI entirely, removing the need to signal HARQ process identifiers in downlink control information. Instead, HARQ process identification is derived from resource mapping parameters that are already present in the scheduling decision, eliminating redundant information transmission.
Solution Approach 2:
Instead of the conventional approach where DCI explicitly signals HARQ process IDs, the patent inverts the logic by deriving HARQ process IDs from resource allocation parameters. The HARQ process identification emerges from the resource mapping rather than being directly commanded, fundamentally changing the information flow direction.
3Productivity
If the number of simultaneous HARQ processes is increased to handle high traffic volumes at large SCS, then throughput capacity improves, but latency increases due to additional signaling events per process
Solution Approach 1:
The patent establishes predetermined rules and formulas for deriving HARQ process IDs from resource parameters before actual transmission occurs. Both transmitter and receiver are pre-configured with the same derivation logic, eliminating the need for real-time HARQ ID signaling and reducing per-process latency while maintaining high throughput capacity.
Data Source
AI summary
A method, system and apparatus for hybrid automatic repeat request (HARQ) process handling at extremely large subcarrier spacing (SCS) are disclosed. According to one aspect, a method in a network node includes configuring a first wireless device (WD) of a plurality of WDs with a maximum number N of HARQ process numbers (HPN) corresponding to N HARQ processes between the first WD of the plurality of WDs and the network node, the maximum number N being based at least in part on a traffic requirement of at least one WD of the plurality of WDs.