Cognitive radio (CR) systems are designed to utilize the available radio spectrum in an efficient and intelligent manner. Terrestrial Digital Video Broadcasting (DVB-T) frequency bands are one of the future candidates for cognitive radio applications especially because after digital television transition the TV white spaces (TVWS) became available for radio communication. This paper deals with the survey of the DVB-T spectrum; wideband measurements were performed on mobile platform in order to study the variation of the radio signal power in city area aboard a moving vehicle. The measurement environment was a densely built-in region where the proper DVB-T receiving was guaranteed by three TV transmitters, utilizing three central channel frequencies using 610, 746, and 770 MHz. In our paper the methods, the applied antenna, and measurement devices will be presented together with simulated and measured fading statistics. The final result is an estimation of the cognitive DVB-T spectrum utilization opportunity; furthermore a scenario is also proposed for secondary channel usage.

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The main goal of the Cognitive Radio (CR) systems is the intelligent and efficient utilization of the radio spectrum. In this paper we introduce our survey in wideband spectrum measurement for studying the Terrestrial Digital Video Broadcasting (DVB-T) frequency bands that are one of the future candidates for cognitive radio applications. The actuality of this subject is that during 2013 Hungary changed the analogue terrestrial broadcasting system to DVB-T, partly freeing up several TV bands, thus opening the opportunity for cognitive systems as well. The regulation of the usage this new band (TV white space, TVWS) is in our country is under development so it is an actual issue. In our paper the methods, the applied antenna and measurement devices will be presented together with fading statistics and predictions about the possibilities of the cognitive spectrum utilization.

In this paper we propose a specific beacon receiver structure for the Alphasat TDP#5 Q/Ka band propagation experiment. The main goal of the experiment is to refine the existing propagation models based on the received data from several different geographical locations over Europe, and also to propose new ground station structures for the experimenter's community. The specialty of our receiver that it is composed from the key elements of terrestrial point to point microwave radios, tailored to the requirements of the beacon receiver. In our paper the hardware elements, the real-time data processing capabilities and preliminary received time series will be demonstrated.