High-Precision Measurement of Dual-Mixer Time Difference System Based on Software-Defined Radio
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DOI: 10.23977/CNCI2020062
Author(s)
Juan Song, Qingan Ding, Bowen Nie, Lijun Zhang, Changqing Liu and Xiaojuan Wang
Corresponding Author
Qingan Ding
ABSTRACT
A novel high-precision digital dual-mixer time diffidence (DMTD) system is proposed based on the principle of the traditional DMTD method combined with the design concept of software-defined radio (SDR). In order to measure and monitor the frequency scale with high precision in real-time through the value of Allan deviation, the digital down-converter (DDC) is used to convert high-frequency signals into baseband signals. In the novel DMTD system, there are no sinusoidal-pulsed converter and zero-cross detector so that the influence of instrument noise can be reduced and more accurate measurement results can be obtained. Furthermore, the proposed system is simulated and the feasibility of system is also verified by using the SIMULINK. Applying the standard 20 MHz sinusoidal signals for testing, a measurement precision (standard deviation) of 8.14×10-14(τ=ls) is obtained, which shows that the proposed DMTD measurement method is practical in SDR.
KEYWORDS
Dual-mixer time difference; software-defined radio; allan deviation; digital down-converter; SIMULINK