Due to the increase of air traffic, in the last 50 years the average spacing between two aircraft has steadily decreased. In order to continue ensuring the safety, technologies for air traffic control, trajectory planning and collision avoidance had to be developed or revised. The objective of this thesis was the realisation of a receiver for one of the newest among these technologies: ADS-B (Automatic Dependent Surveillance-Broadcast).

An ADS-B-equipped aircraft broadcasts about four times per second and by means of a 1090MHz-signal called "extended squitter" information like position, altitude, heading, identification code etc. ADS-B is therewith a system supposed to open up new vistas in the surveillance of air traffic. Up to now, pilots didn't have the possibility of being aware of the position of aircraft in a wide area around them. In ADS-B equipped aircraft, cognition of the traffic situation is made possible by means of a cockpit-display looking similar to the radar screens used by air traffic controllers.

The realized digital signal processing unit is based on a programmable device (FPGA), which receives digital data corresponding to the squitter from an analog-digital converter. Following tasks have to be fulfilled from the device: - Identifying the leading pulse sequence (preamble)

• Identifying the leading pulse sequence (preamble) - Decoding all 112 data-bits and determining their reliability - Correcting the errors if necessary - Preparing the acquired information for further application

The modalities for the implementation of these functions are prescribed in the smallest detail, as usual in avionics. This required a precise approach in developing the solution and, after its realisation, a concluding and extensive run of simulations and tests to verify the compliance with the specifications.