基于相差变化率的GSM-R干扰源直接定位技术OA

Mobile communication operators have deployed public mobile communication networks along the railway,and the Global System of Mobile Communication(GSM)used is the same as the Global System of Mobile Communication for Railways(GSM-R)in principle and standard,causing certain interferences to the GSM-R.In order to locate these interference sources,an interference source location technology based on phase difference change rate has been proposed.The technology is based on the binary array receiving system.According to the space-time relationship between the array element and the interference source,the relational model is initially established based on the azimuth change rate and the interference source position.With the help of the differential deformation,the interference source position solution model and solution method with the change rate of phase difference as the independent variable are established.In order to avoid the influence of abnormal samples in the collected data on the final positioning results,an abnormal sample filtering algorithm based on isolated forest is designed.A multi-dimensional feature space is constructed by using the characteristic attributes of data points to detect and eliminate abnormal data points.A real environment is built to collect and analyze the radio data along the railway line.The results show that the proposed abnormal sample filtering algorithm based on isolated forest can effectively eliminate abnormal data and improve the overall quality of the samples.Using the same wireless acquisition data of interference sources with known positions,the positioning capability comparison test is carried out with the positioning method based on frequency difference change rate and the positioning method based on amplitude change rate,and the minimum positioning error of each interference source is calculated by different methods.The results show that the average positioning error of the method based on frequency difference and amplitude crate of change is 7.18 times and 20.73 times that of the proposed method respectively,which proves that the positioning accuracy of the proposed method is significantly superior to that of the method based on frequency difference rate of change and that of the method based on amplitude rate of change,and has higher positioning accuracy.