Timestamp Compensation Using Dual Clock Counters
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Solution Overview
Problem
The precision of timestamp synchronization in communication networks, particularly in IEEE 1588 systems, is limited by the frequency of time counters, resulting in a maximum precision of 8ns, which is inadequate for reliable handover of base stations during user movement in mobile communication networks.
Innovation Solution
The method involves setting two 80-bit time counters with different clock sources, acquiring timestamp values from both counters at a preset time point, calculating a compensation value by averaging or adding integer and nanosecond parts, and compensating the integer part of the timestamp to improve precision, allowing simultaneous counting by local and service clocks in two domains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single 125MHz clock source is used for time counting, then the system structure is simple, but the timestamp precision is limited to 8ns
Solution Approach 1:
The patent divides the time counting function into two independent segments: a first time counter using a first clock source and a second time counter using a second clock source. Each counter operates independently with its own clock, allowing both to contribute to the final timestamp through their respective counting results, thereby improving precision without requiring a single complex high-frequency clock system
Solution Approach 2:
The patent merges the counting results from two different time counters into a unified timestamp. By combining the first timestamp value from the first counter and the second timestamp value from the second counter, the system achieves higher precision than either counter could provide individually, while maintaining relatively simple clock source configurations
2Measurement precision
If the time counter frequency is increased to improve precision, then the timestamp precision improves, but the system cost and complexity increase
Solution Approach 1:
Instead of using a single high-frequency counter, the patent segments the counting function into two counters operating at different frequencies. The first time counter and second time counter can have different clock frequencies and counting rates, allowing the system to achieve high precision through their combined results without requiring both counters to operate at excessively high frequencies
Solution Approach 2:
The patent changes the operating parameters of the two time counters to different clock frequencies and counting rates. By adjusting these parameters independently for each counter, the system optimizes the balance between precision and complexity, allowing one counter to operate at a higher frequency while the other operates at a lower frequency, thereby reducing overall system complexity while maintaining high precision
Data Source
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AI summary
A method and device for compensating a timestamp of a clock are provided. Herein, the method includes that: a first time counter and a second time counter are set respectively by using clocks of different sources (11); a first timestamp value read from the first time counter and a second timestamp value read from the second time counter are acquired respectively by using a timestamp record signal at a preset time point (12); a timestamp compensation value is acquired according to the first timestamp value and the second timestamp value (13); and the integer part of a timestamp of a clock in a local system is compensated according to the timestamp compensation value (14). The method and device can improve the precision of the timestamp in a local system.