5G NR SSB Time Shifting for Lower Inter-Sector Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing 5G NR systems face interference issues among SSBs of different cells due to their use of the same frequency and time slot, leading to suboptimal SINR levels that affect accessibility and complicate network operations.
Innovation Solution
Implementing SSB time shifting and configuring different SSB indices for each sector using a Radio Resource Controller (RRC) and Medium Access Control (MAC) Scheduler to avoid interference, ensuring no PDSCH is scheduled on the same RB and symbols that would interfere with SSBs in other sectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If SSB is transmitted in the same frequency and time slot for all cells, then network operation is simplified, but interference among SSBs of different cells increases
Solution Approach 1:
The patent divides the time domain by assigning different SSB indices (0, 1, 2, 3) to different sectors, effectively segmenting the transmission time slots. This segmentation allows each sector to transmit SSB in different time slots, eliminating simultaneous transmission interference while maintaining simplified network operation through automated index assignment.
Solution Approach 2:
The patent introduces dynamic SSB index assignment where the RRC controller automatically determines SSB indices based on sector identification. This dynamic allocation allows the system to adaptively assign time slots to different sectors, transforming a static interference problem into a dynamically managed resource allocation problem that resolves interference while maintaining operational simplicity.
2Object-affected harmful factors
If SSBs are positioned in different RBs in different sectors, then SSB interference is reduced, but PDSCH from other sectors still causes interference and handover complexity increases
Solution Approach 1:
The patent segments the time domain by assigning different SSB indices to different sectors, which divides the transmission opportunities. This segmentation prevents PDSCH from other sectors from causing interference to SSB in the current sector, as each sector has dedicated time slots for SSB transmission, thereby reducing interference without increasing handover complexity.
Solution Approach 2:
The patent introduces the SSB index as an intermediary parameter that mediates between sector identification and resource allocation. The RRC controller uses this intermediary to automatically determine appropriate SSB indices, which then serve as the basis for MAC scheduler decisions, creating a layered control mechanism that simplifies the overall system while preventing interference.
3Reliability
If SSB time shifting is implemented with different SSB indices, then SINR is improved by reducing interference, but scheduling complexity increases
Solution Approach 1:
The patent implements self-service through automated SSB index assignment where the RRC controller automatically determines the appropriate SSB index for each sector based on pre-configured rules. This self-service mechanism eliminates the need for manual scheduling intervention, automatically resolving interference issues while maintaining simple operational procedures despite the increased scheduling complexity.
Solution Approach 2:
The patent changes the time domain parameter by introducing different SSB indices (0, 1, 2, 3) corresponding to different time slots. This parameter change transforms the interference problem into a time-division problem, where the MAC scheduler simply needs to avoid assigning PDSCH to time slots occupied by SSB, thereby improving SINR while managing scheduling complexity through clear temporal separation.
Data Source
AI summary
A system for optimizing signal to interference plus noise ratio (SINR) of a 5G New Radio (NR) network including multiple cell sites each having at least one sector, and at least one of the cell sites in communication with a user equipment (UE), the system includes: a radio resource controller (RRC) configured to control a combination synchronization signal and physical broadcast channel block (SSB) locations for all sectors of the cell sites; and a medium access control (MAC) scheduler configured to schedule SSB in each sector in at least one of frequency and time; wherein the RRC configures SSB indices for all sectors of the cell sites so that no two immediately adjacent sectors share the same SSB index.