NR-U PUCCH Interlace Cyclic Shift Optimization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The increasing number of user equipment (UEs) in 5G networks poses challenges in managing uplink transmissions efficiently, particularly in unlicensed bands, where peak-to-average power ratio (PAPR) and cubic metric (CM) issues arise due to interlaced physical uplink control channel (PUCCH) transmissions, affecting the performance of New Radio (NR) systems.

Innovation Solution

The proposed solution involves enhancements to NR PUCCH formats, specifically through cyclic shift ordering and interlace-based allocation, which include repeating length-12 sequences across PRBs and optimizing cyclic shift patterns to control PAPR/CM, and allowing multiple interlace allocations to maximize PRB usage, thereby improving PUCCH performance in unlicensed bands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If interlaced PUCCH transmissions are used in unlicensed bands, then spectrum utilization is improved, but PAPR and CM issues worsen

Engineering Contradiction:

Improvespectrum utilizationVSAvoidPAPR and CM

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by modifying the cyclic shift values assigned to different PRBs within an interlace. Specifically, it uses a cyclic shift pattern where the cyclic shift for the i-th PRB is calculated as (base_cyclic_shift + i*delta_cyclic_shift) mod 12, where delta_cyclic_shift is optimized to reduce PAPR and CM while maintaining spectrum utilization benefits of interlaced transmission

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If multiple interlace allocations are allowed, then PRB usage is maximized, but system complexity increases

Engineering Contradiction:

ImprovePRB usageVSAvoidsystem complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent segments the uplink bandwidth into multiple interlaces, where each interlace consists of non-contiguous PRBs separated by a fixed gap. This segmentation allows independent allocation and management of each interlace, maximizing PRB utilization while simplifying the scheduling complexity through modular resource organization

Inventive Principle:

Principle #1Segmentation

3Object-affected harmful factors

If cyclic shift ordering is optimized, then PAPR/CM is reduced, but processing complexity increases

Engineering Contradiction:

ImprovePAPR/CMVSAvoidprocessing complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements periodic cyclic shift patterns where the cyclic shift values follow a regular sequence across PRBs. This periodic structure enables the use of efficient algorithms for PAPR reduction while maintaining manageable processing complexity through predictable, repeating patterns rather than arbitrary assignments

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS11641693B2NR-U interlace-based PUCCH transmission

Publication Date: 2023.05.02 INTEL CORP

AI summary

Systems and methods for interlace PUCCH transmission in 5G networks are described. The gNB sends an RRC message to a UE. The RRC message provides one or more PUCCH interlace allocations within a BW. Each PUCCH interlace allocation has a PUCCH format for each PUCCH interlace. Each PUCCH format contains a different PUCCH interlace index. The UE sends a PUCCH interlace in the BWP based on the PUCCH interlace allocation. A PUCCH in the allocated PUCCH interlace has a cyclic shift that is dependent on a resource block number in the allocated PUCCH interlace within the BWP.