Multi-Hop Mobile Relay Initial Ranging Timing Synchronization
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Solution Overview
Problem
In multi-hop mobile relay systems, the initial ranging process of user equipment often interferes with other equipment's signals due to timing errors, leading to inter-symbol interference (ISI) and inter-channel interference (ICI), which reduces the base station's reception rate during periodic and handover ranging.
Innovation Solution
The method involves predicting the uplink start point of the base station using periodic ranging information from adjacent user equipment and synchronizing the initial ranging code with the base station's uplink timing, minimizing timing errors by measuring and determining the timing of adjacent ranging processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If user equipment transmits initial ranging code using arbitrarily stored timing value and power value, then the initial ranging process can be performed, but timing error occurs causing inter-symbol interference and inter-channel interference with other user equipment's ranging signals
Solution Approach 1:
The system performs preliminary ranging operations before initial ranging. Adjacent user equipment performs periodic ranging first, and the measured timing information from these preliminary operations is used to determine the optimal timing for the initial ranging code transmission, preventing timing conflicts before they occur
Solution Approach 2:
The base station measures timing values from periodic ranging signals of adjacent user equipment and feeds back this information. The initial ranging user equipment uses this feedback to adjust its transmission timing, ensuring synchronization with the base station's uplink timing and avoiding interference
2Productivity
If initial ranging is performed simultaneously with periodic ranging and handover ranging, then resource utilization is maximized, but reception rate deteriorates due to timing errors acting as interference signals
Solution Approach 1:
Periodic ranging is performed as a preliminary action before initial ranging. The timing information obtained from periodic ranging of adjacent user equipment is used to pre-determine the optimal transmission timing for the initial ranging code, ensuring it does not conflict with other ranging operations
Solution Approach 2:
The timing measurement mechanism acts as an intermediary between periodic ranging and initial ranging. By measuring timing from periodic ranging signals and using this measurement to set the initial ranging timing, the system mediates between simultaneous operations to prevent interference while maintaining resource utilization
Data Source
AI summary
Provided is a method and apparatus for determining timing for initial ranging of user equipment by using ranging of adjacent pieces of user equipment in a multi-hop mobile relay (MMR) system, and more particularly, a method and apparatus for determining timing for initial ranging of user equipment in which a power value and a timing value for periodic ranging of adjacent pieces of user equipment are measured so as to minimize an uplink timing error of a base station. In the MMR system, user equipment transmits an initial ranging code to the base station with irregular timing while not knowing an exact start point of an uplink of the base station. In particular, if the user equipment attempts the initial ranging at the same time as when adjacent pieces of user equipment attempt the periodic ranging and the handover ranging, an error occurs between transmission timing of the initial ranging and uplink timing, thereby acting as an inter-symbol interference (ISI) and inter-channel interference (ICI) of different ranging. As a result, the initial ranging acts as an interference signal in a ranging process of adjacent pieces of user equipment. However, the apparatus and method can minimize a timing error of the initial ranging code of user equipment by avoiding the initial ranging acting as the interference signal.