VDL Mode 2 Equalizer

Very High Frequency Digital Link Mode 2 (VDL Mode 2 or VDL2) is an Air/Ground data link that is widely used in air traffic control and airline operation control. As the air traffic management system is becoming increasingly automated and connected, the performance of the VDL2 network has become more and more important for the safety, security, and efficiency of airspace operations. Recent VDL2 performance monitoring has revealed the issue of channel fading - a major problem that causes missed message receptions and reduces the VDL2 network performance. When the signal propagation channel between a transmitter and a receiver affects the signal being transmitted, channel fading occurs. This can be due to reflections off terrain, shadowing, the Doppler effects, multipath effects, or atmospheric conditions, which can all contribute to increased inter-symbol interference at the receiver. This inter-symbol interference distorts the received signal, making it difficult for the receiving device to detect and decode the message, resulting in increased missed message reception rate.In this paper, we present an innovative VDL2 equalizer technique which has the potential to reduce the missed reception rate of VDL2 signals that are affected by channel fading. Equalizer is a digital signal processing technique which is widely used to compensate the signal distortion caused by the propagation channel. This paper contains a comprehensive description of the proposed VDL2 equalizer. To ascertain the effectiveness of the proposed equalizer, numerical models for both the Least Mean Square (LMS) and Recursive Least Square (RLS) equalization algorithms have been developed. Our simulation results demonstrate that the VDL2 equalizer is capable of counteracting the effects of channel fading and improving the performance of the VDL2 network.