Hava trafik hizmetlerinde VHF veri teknolojisi

ABSTRACTVHF DATA TECHNOLOGY IN AIR TRAFFIC SERVICESBELL KL , Ahmet ErenIn this thesis, we have introduced communication, navigation and surveillancesystem?s working principles and bottlenecks based on working performances used inAir Traffic Control systems. We investigated the possible system solution to meetcurrent bottlenecks, safety issues and Air Traffic growth handling for today and inthe future.Air Traffic Navigation continuation and communication quality regarding safetyissues are directly dependent on the chosen technology base. Choosing the righttechnology to meet requirements is what we have searched in this thesis.The baseline technology of Broadband -VHF project is as in the fourth generation(4G) mobile communications.ivB-VHF approaches communication in two different ways The one from groundstations to aircrafts (forward link) is based on combination of OFDM-CDMA calledMC-CDMA and the second link from aircraft to ground (reverse link) is based oncombination of OFDM-FDMA. We added Code Division Multiplexing into thereverse link to enhance the link robustness against interferences and data security. Inorder to realize this, we developed a Matlab code to simulate its performances toobserve whether this combination provides robustness against interferences. Usingthe simulation we have obtained BER results at different cyclic prefix, number ofOFDM symbols, code length size and channel settings. BER obtained with theinclusion of CDM are slightly favorable as compared to OFDM only reverse link,however, the performance improvement is not within the expected scale.v