Base Station Clock Synchronization via Air Interface Frequency Reference
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Solution Overview
Problem
Current wireless communication systems face challenges in achieving accurate timing for base stations due to the high cost and complexity of stable oscillators, as well as the unreliability of GPS signals, especially in indoor environments, where additional receivers are required and energy consumption is high.
Innovation Solution
A method and device for transmitting clock synchronization data using a frequency reference below 400 MHz via an air interface and a transport network, allowing for time and frequency stability using a less precise oscillator, which eliminates the need for costly temperature regulation and reduces energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a stable oscillator with temperature regulation is used to achieve accurate timing, then timing accuracy is improved, but device complexity and cost increase due to additional temperature regulation arrangements
Solution Approach 1:
The patent introduces an intermediary frequency reference signal transmitted via air interface that mediates between the network clock and the base station's local oscillator. This external reference allows the base station to achieve accurate timing without requiring complex internal temperature regulation arrangements, as the frequency reference provides the necessary stability externally.
Solution Approach 2:
The patent replaces the mechanical/thermal system of oven-controlled oscillators with an electromagnetic field-based solution. Instead of heating and maintaining physical oscillators at specific temperatures, the system uses radio frequency signals to carry frequency reference information, substituting thermal control with electromagnetic signal processing.
2Measurement precision
If GPS receivers are used for time and frequency synchronization, then timing accuracy is improved, but device complexity and energy consumption increase due to additional receivers
Solution Approach 1:
The patent makes the existing air interface universally serve multiple functions: it not only carries communication data but also transmits frequency reference signals for synchronization. This eliminates the need for separate GPS receivers, as the same wireless infrastructure provides both communication and timing functions.
Solution Approach 2:
The system uses its own communication infrastructure to provide synchronization services. The network transmits frequency reference signals through the existing air interface, allowing the base station to self-synchronize without requiring external GPS equipment or additional specialized receivers.
3Measurement precision
If stable oscillators with temperature regulation are used, then timing accuracy is improved, but energy consumption increases due to continuous heating
Solution Approach 1:
Instead of continuous heating to maintain oscillator stability, the system uses periodic frequency reference signals transmitted over the air interface. The base station updates its timing based on these periodic references, eliminating the need for continuous energy-consuming heating while maintaining accuracy through intermittent synchronization.
4Productivity
If high frequency carriers are used for communication, then bandwidth is improved, but timing accuracy requirements become more stringent
Solution Approach 1:
The patent segments the timing synchronization function from the data communication function. Frequency reference signals for timing are transmitted separately from data traffic, allowing independent optimization of each. This segmentation enables high-frequency data communication while maintaining stringent timing accuracy through dedicated reference signals.
Data Source
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AI summary
The invention relates to transmission and reception of clock synchronization data in a wireless communication system. According to the invention a device for transmitting clock synchronization data obtains at least one time reference of a wireless communication system clock, controls transmission of a frequency reference of the wireless communication system clock via an air interface of the wireless communication system, and provides transmission of the time reference via a transport network associated with the wireless communication system, while the base station receives the frequency reference, locks an own oscillator to the frequency of the frequency reference, receives the time reference from the transport network and adjusts timing that is controlled by the oscillator based on the time reference.