Study of the effect of harmonic interference from a high voltage power line on the operation of a non-linear receiving device for continuous automatic locomotive signalling with a correlation decoder

This paper considers a continuous automatic locomotive signalling (CALS) receiver with a correlation decoder. The aim of this paper is to investigate the influence of harmonic interference from a high-voltage power line on the operation of a non-linear CALS receiver with a correlation decoder. The experimental study of the quality of operation of a non-linear CALS receiver with a correlation decoder under the influence of harmonic interference from high-voltage power lines was carried out using the simulation method. Simulation models of interference from a high-voltage power line (VPL), a receiver and a correlation decoder of the CALS channel were used in the study. The analysis of oscillograms obtained as a result of the study has shown that the correlation decoder has a number of features due to the algorithm of its functioning. The correlation decoder more confidently accepts code combinations with a duration of 1.6s (generated by the code track transmitter of CTT-5 type), than the duration of 1.86s (generated by the code track transmitter CTT-7). This is expressed in a shorter time interval of disturbance of the CALS non-linear receiving device. At decoding of the code combination (CC) with the duration of both 1.6 s and 1.86 s the situation of short-term decoding of the more permissive CC «Y» instead of «RY» was observed. However, the duration of these situations did not exceed two code cycles and would not have caused a more permissive light to appear at the locomotive traffic light. In general, the experiments have shown that the CALS CC correlation decoding algorithm needs improvement for more confident decoding of CCs produced by a code track transmitter of the CTT-7 type(1.86 s).