PUCCH Slot Determination for Multi-SCS TDD Networks
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Solution Overview
Problem
In 5G NR wireless networks, the varying numerologies or subcarrier spacings lead to challenges in determining the appropriate slot for physical uplink control channel (PUCCH) transmission, especially in time division duplex (TDD) operations, where HARQ-ACKs need to be delayed to ensure valid symbol transmission, and multiple cells with different subcarrier spacings may coincide, requiring precise slot selection.
Innovation Solution
A client device receives PUCCH configuration information including relative slot offset values from a network node device, which allows it to select a PUCCH transmission slot for target serving cells with larger subcarrier spacings by using radio resource control (RRC) parameters, such as DataToUL-ACK or DataToUL-ACK_rel_offset, and determines the slot based on the reference cell's timing and pattern, ensuring accurate PUCCH slot alignment and effective HARQ feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple serving cells with different subcarrier spacings are configured for PUCCH transmission, then network flexibility and adaptability are improved, but slot alignment precision and transmission reliability deteriorate due to timing mismatches between cells
Solution Approach 1:
The patent applies local quality by configuring cell-specific relative slot offset values (k1_rel) for each target serving cell. This allows each cell with different subcarrier spacing to have customized timing offset parameters, ensuring that PUCCH transmission slots are properly aligned with PDSCH slots on the reference cell while maintaining the adaptability to support multiple numerologies.
2Reliability
If HARQ-ACK transmission is delayed to ensure valid symbol transmission in TDD operation, then transmission reliability is improved, but transmission latency increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring the set of relative slot offset values (k1_rel) through RRC signaling before actual PUCCH transmission. This allows the UE to determine the appropriate PUCCH slot in advance by selecting from the pre-configured offset values, ensuring that the selected slot contains valid uplink symbols while minimizing unnecessary delays.
3Measurement precision
If multiple PUCCH configurations are provided per bandwidth part, then configuration precision and control granularity are improved, but device complexity and processing overhead increase
Solution Approach 1:
The patent applies segmentation by dividing PUCCH configuration into multiple independent sets, each associated with a specific bandwidth part. The network can configure multiple PUCCH parameter sets (including different k1_rel values) for different BWPs, allowing precise control of PUCCH timing for each bandwidth part while enabling the UE to select only the relevant configuration for the active BWP, thus managing complexity.
Data Source
AI summary
Devices, methods and computer programs for a packet data unit session for physical uplink control channel transmission slot determination are disclosed. A client device receives from a network node device physical uplink control channel, PUCCH, configuration information for configuring more than one serving cell for a PUCCH transmission within a PUCCH cell group for the client device. The PUCCH configuration information comprises at least one set of relative slot offset values n for at least one target serving cell for the PUCCH transmission having a larger sub-carrier spacing, SCS, than an SCS of a reference cell. The client device utilizes the received PUCCH configuration information in selecting a PUCCH transmission slot for a target serving cell.