Staggered SSB Beam Sweeping for Wireless Initial Access

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently identifying and accessing initial system information for user equipment (UE) during the initial access procedure in beamformed communications, particularly in staggered synchronization signal blocks (SSBs) across multiple frequency sub-bands, which affects the reliability and efficiency of network access.

Innovation Solution

The implementation of staggered synchronization signal blocks (SSBs) and control channel transmissions using multiple transmission beams in a beam sweeping procedure, where SSBs are transmitted in a single frequency sub-band during initial access and control channel transmissions span additional frequency sub-bands, allowing for increased power spectral density and efficient detection of system information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If SSBs are transmitted across multiple frequency sub-bands simultaneously, then detection reliability improves, but power spectral density decreases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidpower spectral density
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent divides the frequency band into multiple sub-bands and transmits SSBs in a staggered manner across these sub-bands at different time instances. This segmentation allows the system to concentrate power in one sub-band at a time (maintaining high PSD) while still achieving reliable detection across the entire frequency band through the staggered transmission approach.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs periodic transmission of SSBs across different frequency sub-bands at staggered time instances. This periodic action ensures that each sub-band receives sufficient power for reliable detection while distributing the overall transmission across time, thereby maintaining high power spectral density in each individual transmission instance.

Inventive Principle:
Principle #19Periodic action

2Productivity

If control channel transmissions span multiple frequency sub-bands, then system information delivery improves, but power spectral density decreases

Engineering Contradiction:
Improvesystem information deliveryVSAvoidpower spectral density
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The control channel transmissions are segmented across multiple frequency sub-bands, with each sub-band carrying a portion of the system information. This segmentation allows the system to deliver comprehensive system information while maintaining adequate power spectral density in each sub-band transmission.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a time dimension to the frequency sub-band transmissions by using staggered time instances. This allows control channel information to be delivered across multiple frequency sub-bands without requiring simultaneous transmission, thereby maintaining power spectral density while improving overall system information delivery.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If beam sweeping procedure uses multiple transmission beams, then initial access reliability improves, but access time increases

Engineering Contradiction:
Improveinitial access reliabilityVSAvoidaccess time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The beam sweeping procedure is segmented across multiple frequency sub-bands with each sub-band carrying information for specific beams. By staggering the transmissions across sub-bands, the system can cover multiple beams while reducing the total time required compared to sequential beam sweeping, thus improving initial access reliability without excessive time loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses periodic beam sweeping across frequency sub-bands at staggered time instances. This periodic approach allows the system to efficiently cover multiple transmission beams by leveraging the periodic structure, thereby improving initial access reliability while minimizing the time penalty through optimized periodicity.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3918725B1Staggered synchronization signal blocks in frequency sub-bands for beamformed wireless communications
Publication Date: 2024.12.04 QUALCOMM INC
  • EP3918725B1 patent drawingFigure 1
  • EP3918725B1 patent drawingFigure 2
  • EP3918725B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described that provide staggered synchronization signal blocks (SSBs) in frequency sub-bands for beamformed wireless communications. Transmissions of SSBs and control channel transmissions (e.g., remaining minimum system information (RMSI) physical downlink control channel (PDCCH) transmissions) may use multiple transmission beams in a beam sweeping procedure. The SSB transmissions may be transmitted using transmission beams that span one frequency sub-band of a number of available frequency sub-bands, and the control channel transmissions may use transmission beams that span two or more of the frequency sub-bands. The SSB beam sweeping procedure may be performed separately during staggered, non-overlapping time periods for each frequency sub-band of the number of frequency sub-bands. Each of the of SSBs may indicate a reference timing of the base station used to identify a set of resources (e.g., a control resource set (CORESET)) that carries control channel transmissions.