Hierarchical Cell Initial Access via Macro Intermediary
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In conventional wireless communication systems, legacy Mobile Stations (MSs) face difficulties in detecting and synchronizing with small cells, especially when the small cell does not have a synchronization channel or when the MS cannot recognize it, leading to challenges in establishing communication.
Innovation Solution
The proposed solution involves an initial access procedure where the MS transmits an initial access message, obtains information about the small cell BS from a response message received from the macro BS, attempts to decode a reference channel, and sets a downlink channel with the small cell BS when successful, while the macro BS periodically transmits synchronization signals and system information and determines whether the small cell reports an initial access trial, providing necessary correction values and identification information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the synchronization channel of the existing macrocell is reused in the additional small cell, then overhead can be reduced and data rate can increase, but legacy MS cannot detect the small cell and cannot carry out synchronization
Solution Approach 1:
The macro base station acts as an intermediary to bridge the communication gap. It receives the initial access message from the mobile station, determines that a small cell base station should handle the access, and then transmits a response message containing small cell identification information and reference channel information back to the mobile station through the macro base station. This intermediary approach enables legacy mobile stations to access small cells without requiring them to directly detect or synchronize with small cell synchronization channels.
2Productivity
If the small cell does not have the synchronization channel or the legacy MS cannot recognize the synchronization channel by itself, then frequency utilization can be optimized, but the MS cannot detect the small cell and establish communication
Solution Approach 1:
The system performs preliminary actions by having the macro base station pre-process the initial access message and prepare the response information before the mobile station even attempts to detect small cell synchronization channels. The macro base station determines in advance which small cell should handle the access and prepares the response message with small cell identification and reference channel information, enabling the mobile station to establish communication without needing to independently detect small cell synchronization channels.
3Ease of operation
If legacy MS transmits initial access message to macro BS, then the message can be received, but the MS cannot obtain direct access to small cell without intermediary procedures
Solution Approach 1:
The system merges the macro base station's reception capability with the small cell base station's service capability. The mobile station transmits the initial access message to the macro base station (which has broad coverage and reliable reception), and the macro base station combines this with small cell identification information in the response message. This merging allows the mobile station to access the small cell through the macro base station's intermediary response, maintaining ease of operation while enabling small cell access.
Data Source
AI summary
An initial access procedure in a wireless communication of a hierarchical cell structure includes operations of a mobile station (MS). The operations of the MS include transmitting an initial access message; obtaining information of a small cell Base Station (BS) which receives the initial access message, from a response message received from a macro BS; attempting to decode a reference channel transmitted by the small cell BS; and when successfully decoding the reference channel, setting a downlink channel with the small cell BS.