NCR Beam Determination via SSB Feedback
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently determining beams for access links between a Network-Controlled Repeater (NCR) and a User Equipment (UE) during the initial access procedure, particularly when receiving a Physical Random Access Channel (PRACH) preamble.
Innovation Solution
The method involves receiving configuration information from a base station, transmitting synchronization signal blocks (SSBs) to the UE, and determining the direction of an uplink transmit beam based on the direction of a downlink receive beam used for receiving the SSBs, thereby facilitating the transmission of a PRACH preamble.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If beam determination methods are not optimized for NCR-UE access links, then existing wireless communication systems can operate with standard procedures, but initial access reliability deteriorates in scenarios with coverage holes or blockages
Solution Approach 1:
The patent applies preliminary action by having the UE determine the uplink transmit beam direction based on the downlink receive beam direction before transmitting the PRACH preamble. The UE receives SSBs from the NCR using downlink receive beams, determines the corresponding uplink transmit beam directions in advance, and then uses these predetermined beams for PRACH transmission. This preliminary beam determination ensures reliable initial access even in coverage holes or blockages without requiring complex real-time beam searching.
2Measurement precision
If the UE performs comprehensive beam searching for PRACH transmission, then beam direction accuracy improves, but access time and complexity increase
Solution Approach 1:
The patent applies feedback by utilizing the downlink receive beam information as feedback to determine the uplink transmit beam direction. The UE receives SSBs from the NCR using downlink receive beams, and based on the received SSB information and beam correspondence, determines the corresponding uplink transmit beam directions. This feedback mechanism allows the UE to achieve accurate beam direction without performing comprehensive beam searching, thereby reducing access time while maintaining beam direction accuracy.
3Area of stationary object
If multiple SSBs are transmitted with different downlink transmit beams, then coverage area expands, but beam determination complexity increases
Solution Approach 1:
The patent applies self-service by enabling the UE to autonomously determine uplink transmit beam directions based on the received downlink SSB information and beam correspondence principles, without requiring complex network-side beam management. The UE receives multiple SSBs transmitted with different downlink transmit beams from the NCR, and independently determines the corresponding uplink transmit beam directions using the received SSB information. This self-service approach expands coverage area through multiple beams while keeping beam determination complexity manageable at the UE side.
Data Source
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AI summary
There is provided a method of operating an electronic device in a wireless communication system. The method includes receiving configuration information from a base station (BS), receiving a plurality of synchronization signal blocks (SSBs) from the base station, transmitting one or more SSBs of the plurality of SSBs to a user equipment (UE) based on the configuration information, receiving, from the UE, a physical random access channel (PRACH) preamble in a time resource related to a specific random access channel occasion (RACH occasion, RO) associated with a specific SSB of the one or more SSBs, and transmitting the PRACH preamble to the base station based on the specific SSB.