Research On Airborne Vhf Communication System Interference

With the rapid development of civil aviation, today's civil aircraft have a net increase of an annual rate of at least 100, whereas the airlines, routes quantity also makes the sharp increase in the total number of flights, and the aircraft is intensive in the same airspace at the same time, the air traffic is increasingly busy, so that good communication is very important. Reliable communication is needed for real-time monitoring to protect the safety of aircraft flying in the air. VHF communication in the past few decades has been one of the most important means of communication for civil aircraft, which has good effect within a short distance and can achieve close monitoring, voice communication and data transmission between aircraft and aircraft as well as between aircraft and ground.At present, although civil aircraft is installed with many types of communications equipment, VHF communication is preferred to be the most important means of communication in the actual air to air, air to ground communications applications. However, because of the special nature of VHF communications, resulting in on-board VHF equipment vulnerable to all kinds of interference, resulting in air to air and air to ground communications disrupted, and also resulting in the interruption of the ground monitoring data, seriously impact on the air safety of the aircraft.This article does research on the possible interference of airborne VHF communication process through actual case study, including the atmospheric interference, adjacent channel interference, image interference, co-channel interference, intermodulation interference, cross interference, industrial interference, noise disturbance and so on. Among which the civilian board FM radio station has particularly serious interference on the VHF communications, and it is also the focus of this article, including a general interference mechanism and the mechanism of FM radio frequency interference, do a detailed derivation and discussion, and propose the corresponding solutions.This article referred the structure and parameters of the airborne VHF communication equipment in Aircraft Maintenance Manual (AMM) and Component Maintenance Manual (CMM), study the airborne VHF communication support, and cited instances from the aspects of the structure and environment of airborne VHF communication equipment to do research analysis on the source of interference, the interference phenomenon and the same frequency interference caused by the FM radio, and propose the program and measure of co-channel interference resistance. Design a LMS adaptive filter, specifically for wave filtering for FM radio interference, using Matlab to do simulation and research to the solutions, and achieve the research of the mechanism of VHF communication system interference and anti-jamming.