Analysis of Influence of Impedance Matching on Signal Transmission Through Long Wires of XCTD Profiler

摘要

Although expendable conductivity-temperature-depth (XCTD) profiler has been extensively studied, there are relatively few studies on the transmission performance of XCTD channel, which makes it unclear that the signal is affected by the channel in the long-distance transmission process. First, the structure of the XCTD is analyzed. Then, according to the working mode and channel structure characteristics of XCTD, the circuit model of the transmission channel is established. In order to better study the channel compensation method, a laboratory transmission system of XCTD is built. By analyzing the influence of channel impedance parameters on the transmission signal, the channel model of XCTD is optimized, and the compensation channel is determined to be series inductance. Finally, the bit error rate (BER) of unoptimized and optimized channels is compared based on ASK and differential phase-shift keying (DPSK) modulation. It is verified that the optimized channel model of XCTD has a certain significance in reducing the BER of the transmission signal. This article has important theoretical significance and practical application value for the research of transmission signal transmission performance of expendable profiler.