A Low Complexity Digital Channel Filter For LDACS1 in Future Aeronautical Communication Systems
The air traffic has seen a tremendous growth worldwide in the last few decades and is forecast to grow at a rapid
pace in the future as well. Therefore, there is an urgent need to upgrade the decades-old analog communication based air
traffic management (ATM) systems that are currently being used and replace them with new and efficient digital
communication based ATM systems to facilitate the air traffic growthbeing observed worldwide. Consequently, the
International Civil Aviation Organization (ICAO) is developing a new standard for air-to-ground communications, namely
the L-band Digital Aeronautical Communication System (LDACS). Out of the different candidate technologies being
considered for LDACS, the LDACS type 1 (LDACS1) is the most superior and mature candidate. The channel filters used in
LDACS1 transceivers have to adhere to stringent spectral mask specifications to ensure minimal interference with the legacy
systems already deployed in the L-band. This paper presents a design technique to realize a low complexity digital channel
filter for LDACS1.Our channel filter employs two low order sub-filters in cascaded formto shape the resultant frequency
responseaccording to the required LDACS1 spectral mask. We show that if our channel filter is compared with the
conventional one, 43.56% and 45% reductions are observed in multiplication complexity and group delay respectively.
Index terms- Channel filter, low complexity, LDACS1, air-to-ground communication.