Random Access Timing Advance for Ultra-Large Coverage Cells
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Solution Overview
Problem
In LTE communication systems, user equipment (UE) cannot maintain synchronization with base stations in ultra-large coverage cells exceeding 107 kilometers, leading to poor communication quality due to differing transmission delays across the cell.
Innovation Solution
A random access method and apparatus that set a timing advance (TA) and R-bit identifier to adjust uplink transmission timing, allowing UE to synchronize with downlink timing, even in ultra-large coverage cells, by indicating a time granularity or value range of the TA within the random access response message.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a timing advance TA with maximum coverage cell distance of 107 kilometers is used, then synchronization is maintained within that range, but communication quality deteriorates in ultra-large coverage cells greater than 107 Km
Solution Approach 1:
The timing advance TA parameter is segmented into two parts: a traditional TA parameter and a new R-bit identifier. The R-bit identifier specifically indicates time granularity or value range information, allowing the system to handle ultra-large coverage distances by providing additional timing adjustment granularity without affecting the existing TA mechanism for normal coverage areas.
Solution Approach 2:
The invention changes the parameter structure of timing advance by introducing an R-bit identifier that modifies how TA values are interpreted. This parameter change enables the system to support coverage distances greater than 107 Km by providing additional timing adjustment resolution through the R-bit field, which can indicate different time granularities or value ranges for the TA parameter.
2Adaptability or versatility
If the coverage cell distance is increased to support rapid transit scenarios, then adaptability improves, but synchronization between uplink and downlink times deteriorates
Solution Approach 1:
The timing advance information is segmented into the original TA parameter and a new R-bit identifier. This segmentation allows the R-bit to carry specific information about time granularity or value range, enabling the system to maintain synchronization in ultra-large coverage cells by providing more precise timing adjustment control for distant UEs.
Solution Approach 2:
The R-bit identifier acts as an intermediary between the TA parameter and the actual timing adjustment applied. It provides additional information that mediates how the TA value should be interpreted and applied, ensuring proper synchronization even when coverage distances exceed the traditional 107 Km limit.
Data Source
AI summary
Embodiments of the present invention disclose a random access method. In a scenario of an ultra-large coverage cell, the method includes: receiving a random access (RA) preamble sent by user equipment (UE); setting a timing advance TA and an R-bit identifier that are of the ultra-large coverage cell, where the R-bit identifier is used to indicate a time granularity of the timing advance TA or is used to indicate a value range of the timing advance TA; and sending a random access (RA) response message to the UE, where the RA response message includes the timing advance TA and the R-bit identifier, and the ultra-large coverage cell is a cell with a coverage distance greater than 107 Km. Therefore, uplink time and downlink time are aligned when uplink signals sent by UEs in different positions in a cell arrive at a base station.