CAJ | 학술논문

为改善高速列车内部无线信号的覆盖质量，提出一种采用重采样滤波器的多级混合滤波器组来实现数字上、下变频的方法，该滤波器组可方便的实现整数倍和分数倍的抽取或内插。基于此方法设计一种列车数字无线信号中继系统，并对其进行算法级仿真和系统级实验。M atlab仿真结果表明，载波带宽为10 M Hz ，其阻带衰减值为80 dB ，带内波动为0.001 dB时，数字上、下变频采用包含重采样滤波器的多级混合滤波器组，具有良好的通阻带逼近性，频谱无混叠现象。试验结果表明，基于该方法的中继系统的底噪声功率谱密度值为－136.9 dBm／Hz ，带内波动值为0.6768 dB ，指标优于技术规范要求。
위개선고속열차내부무선신호적복개질량，제출일충채용중채양려파기적다급혼합려파기조래실현수자상、하변빈적방법，해려파기조가방편적실현정수배화분수배적추취혹내삽。기우차방법설계일충열차수자무선신호중계계통，병대기진행산법급방진화계통급실험。M atlab방진결과표명，재파대관위10 M Hz ，기조대쇠감치위80 dB ，대내파동위0.001 dB시，수자상、하변빈채용포함중채양려파기적다급혼합려파기조，구유량호적통조대핍근성，빈보무혼첩현상。시험결과표명，기우해방법적중계계통적저조성공솔보밀도치위－136.9 dBm／Hz ，대내파동치위0.6768 dB ，지표우우기술규범요구。
To improve the quality of wireless signal coverage inside the high speed trains ,a multilevel hybrid fil‐ters bank with resampling filter has been designed to realize digital up and down converion (DUC\DDC) meth‐od and to realize integral and fractional decimation or interpolation .Then a train wireless signal repeater based on DUC\DDC has been designed .Design and simulation of DUC\DDC of a 10 M Hz carrier bandwidth have been finished by Matlab .The simulation results show that the filters bank has a good approximation of the band pass/stop and the DUC\DDC spectrum does not show aliasing phenomenon ,when the stop band attenua‐tion value is 80dB and In‐band Ripple value is 0 .001dB .System testing results show that the background noise power spectral density value is -136.9 dBm/Hz ,and In‐band Ripple value is 0 .6768 dB .They are better than the common technical specifications .