Wireless Device Time Synchronization Using Dual-Stage Sampling
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Solution Overview
Problem
Current time synchronization methods in wireless communication devices, such as those used in LTE networks, fail to achieve high timing accuracy and low computational complexity simultaneously, and are not applicable to next-generation networks like 5G due to the absence of Common Reference Signals (CRS).
Innovation Solution
A method for performing both coarse and fine time synchronization using a synchronization signal, where the wireless communication device samples the signal at either the original or reduced sampling rate, selects timing offset values with granularity corresponding to the shortest cyclic-prefix length, performs channel estimations in the frequency domain, transforms results to the time domain, and calculates channel powers to determine the timing, thereby reducing computational complexity while achieving high accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Common Reference Signal (CRS) is used for fine time synchronization, then timing accuracy is improved, but computational complexity and energy consumption increase
Solution Approach 1:
The patent extracts only the necessary timing information from the synchronization signal by using correlation-based detection with cyclic-prefix granularity, rather than employing the full CRS-based fine time synchronization procedure. This extraction approach achieves adequate timing accuracy without the computational overhead of CRS processing.
Solution Approach 2:
The patent segments the time synchronization process into two distinct stages: coarse time synchronization using synchronization signals with cyclic-prefix-based granularity, and fine time synchronization only when necessary. This segmentation allows the system to operate with lower complexity in normal conditions while maintaining the option for higher precision when needed.
2Reliability
If Common Reference Signal (CRS) is transmitted continuously, then timing synchronization is maintained, but energy consumption and interference increase
Solution Approach 1:
The patent employs periodic synchronization signal transmissions with configurable periodicity rather than continuous CRS transmission. The network can adjust the transmission periodicity based on service requirements, achieving a balance between synchronization reliability and energy consumption by transmitting only when necessary.
Solution Approach 2:
The patent changes the transmission parameters of synchronization signals, specifically using reduced sampling rates and selective transmission based on service requirements. This allows the system to maintain synchronization reliability while significantly reducing energy consumption compared to continuous full-rate CRS transmission.
3Measurement precision
If synchronization signal is sampled at original sampling rate, then timing resolution is improved, but computational complexity increases
Solution Approach 1:
The patent changes the sampling rate parameter based on service requirements, using reduced sampling rates for normal operations and original sampling rates only when high precision is needed. This parameter adaptation allows the system to achieve adequate timing resolution for most applications while significantly reducing computational complexity.
Solution Approach 2:
The patent applies partial action by using reduced sampling rates that provide sufficient timing resolution for most services without the full computational burden of original sampling rate processing. The system performs only the necessary amount of processing to achieve adequate synchronization accuracy.
Data Source
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AI summary
A wireless communication device and method therein for time synchronization in a wireless communication network are disclosed. The wireless communication device determines a first timing (tc) by performing a coarse time synchronization based on a synchronization signal received by the wireless communication device, wherein the received synchronization signal is sampled either in an original sampling rate or a reduced sampling rate. The wireless communication device determines a second timing (tf) by performing a fine time synchronization based on the determined first timing (tc) and the received synchronization signal.