Techniques for ensuring co-existence between B-VHF and legacy VHF systems

A promising approach for future air traffic control (ATC) is the multi-carrier based broadband communication system B-VHF operated in the very high frequency (VHF) band. In order to allow for a gradual in-band transition from the current to a future ATC communication system the B-VHF system uses an overlay concept, i.e., the B-VHF system coexists with the current VHF communication systems in the same frequency band until the operation of the current VHF systems has phased out. The two main issues to be solved for a successful co-existence are the avoidance of interference from the B-VHF system to the legacy VHF systems and the suppression of interference from the legacy VHF systems at the B-VHF receiver. Therefore, existing as well as new methods for the reduction of out-of-band radiation of the B-VHF transmit signal are proposed and investigated. Moreover, several efficient concepts are analyzed which mitigate different kinds of interference at the B-VHF receiver. Simulation results show the appropriateness of the proposed schemes