A software defined radio approach for future adaptive mode S transponder

For some years now, aerospace and aviation industries have been demanding for a new approach using a single generic transceiver system, which could be reprogrammable and universal, replacing multiple radios and antennas present in aircraft. The new system would allow simultaneous operation of multiple systems (Communication, Navigation, Surveillance – CNS) on a flexible development platform for future avionics applications. This flexible development platform is based on a Software Defined Radio (SDR) system. This paper reports this new flexible SDR approach for development of a specific avionic system: a mode S transponder application. This task takes part of a more ambitious project currently in development at LASSENA laboratory with the aim of implementing avionics into these types of embedded systems. The project intends to provide avionics with the benefits of SDR technology, i.e. flexibility, reducing total equipment count and weight increased reliability and safety, and reduced time and cost for the design and development, among others. This paper presents also the results of the mode S technology implementation in an SDR. Several functions of a typical mode S transponder are already implemented in our model, and worked as we might expect.