The automatic classification of the modulation format of a detected signal is the intermediate step between signal detection and demodulation. If neither the transmitted data nor other signal parameters such as the frequency offset, phase offset and timing information are known, then automatic modulation classification (AMC) is a challenging task in radio monitoring systems. The approach of clustering algorithms is a new trend in AMC for digital modulations. A novel algorithm called 'highest constellation pattern matching' is introduced to identify quadrature amplitude modulation and phase shift keying signals. The obtained simulation and measurement results outperform the existing algorithms for AMC based on clustering. Finally, it is shown that the proposed algorithm works in a real monitoring environment.
In large aircrafts the cabling is very com p lex and often causes reliability p roblems. This is s p ecially true for modern In-flight Entertainment (IFE) systems, where every p assenger can select a p referred movie, play computer games or be able to communicate with other travellers. Due to EMC p roblems, wireless communication systems (WiFi etc.) didn't succeed in solving these p roblems.In this p a p er an innovative communication system is p ro p osed which p erfectly su pp lements an aircraft IFE system. The key innovation of this system is to use structures that are essential p arts of the airframe for data transfer, such as seat rails. Those rails consist of rectangular sha p es and could easily be modified to fulfill the function of waveguides for microwaves. A waveguide as p art of the seat rail would p rovide enormous benefits for aircrafts, such as a large bandwidth and consequently high data rates, no p roblems with EMC, unlimited flexibility of seat configuration, mechanical robustness with associated increase of reliability and a few additional advantages related to aircrafts such as reduction of weight and costs.
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