CSI-RS Based Time Frequency Synchronization in 5G Terminals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The 5G communication system requires high-accuracy time and frequency synchronization for demodulating high-order QAM signals, while minimizing system load, which is not efficiently addressed by existing methods.
Innovation Solution
A method and apparatus that utilize a channel state information-reference signal (CSI-RS) for terminals to achieve downlink time and frequency synchronization, with the CSI-RS being transmitted by the base station and received by the terminal, allowing for efficient synchronization without increasing system load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If always-on signals such as PSS, SSS, CRS, and CSI-RS are used for time and frequency synchronization, then synchronization accuracy is improved, but system load increases
Solution Approach 1:
The patent applies periodic action by transitioning from always-on synchronization signals to periodic transmission. The CSI-RS is transmitted periodically at specific intervals rather than continuously, reducing system load while maintaining synchronization accuracy. The terminal performs time and frequency tracking based on these periodic CSI-RS transmissions, achieving the desired balance between measurement precision and resource consumption.
2Productivity
If high-order QAM modulation is used to support high resolution image services, then data rate is improved, but requirement for time and frequency synchronization accuracy increases
Solution Approach 1:
The patent implements feedback mechanisms where the terminal continuously monitors the CSI-RS signals and adjusts its time and frequency synchronization based on channel state information. This feedback loop ensures that even with high-order QAM modulation requiring precise synchronization, the system can dynamically adapt and maintain the necessary accuracy levels through iterative refinement of synchronization parameters.
Solution Approach 2:
The system performs preliminary time and frequency synchronization using initial synchronization signals before data transmission begins. This preliminary action establishes a baseline synchronization state that enables subsequent high-order QAM demodulation, ensuring the terminal is properly synchronized before attempting to decode high-rate data streams.
3Quantity of substance
If CSI-RS is used for time and frequency tracking instead of always-on signals, then system load is reduced, but complexity of achieving accurate synchronization increases
Solution Approach 1:
The patent applies universality by making the CSI-RS serve multiple functions simultaneously. The same CSI-RS signal is used for both channel state information acquisition and time-frequency synchronization tracking. This multi-functionality reduces the need for separate dedicated synchronization signals, thereby reducing system load while the terminal's synchronization module is designed to handle the integrated functionality efficiently.
Solution Approach 2:
The system changes parameters of the CSI-RS transmission, such as periodicity, bandwidth, and power allocation, to optimize the balance between system load and synchronization complexity. By adjusting these parameters dynamically based on channel conditions and service requirements, the system achieves accurate synchronization without excessive complexity or resource consumption.
Data Source
AI summary
The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present invention provides a method and an apparatus which can achieve accurate time and frequency synchronization while reducing system load, in line with the design requirements for a 5G communication system. Particularly, the present invention provides a method for acquiring time and frequency synchronization by a terminal in a communication system, the method comprising the steps of: receiving a first synchronization signal from a base station; receiving a second synchronization signal from the base station; and receiving a channel state information-reference signal (CSI-RS) from the base station, and acquiring downlink time and frequency synchronization with the base station on the basis of the CSI-RS.