• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1324-1343
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• 2014

In recent years, the problem of spectrum mobility in Cognitive Radio (CR) Networks has been widely investigated. In order to utilize spectrum resources completely, many spectrum handoff techniques based on game theory have been proposed, but most studies only concern that users how to achieve better payoffs, without much attention to the diverse needs of users. In this paper, we propose a new channel-switching model based on game theory, using a prioritized approach to meet the diverse needs of users in two different modes (CQ and PS). At the same time, this paper proposes some acceleration techniques to reach the Nash equilibrium more efficiently. We evaluate the performance of the proposed schemes depending on priority using real channel availability measurements, and conclude that the channel quality function (CQ) mode provide better service for priority user but the plan-sorting (PS) mode can be more suitable in multiple priority users exist scene.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.5
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• pp.409-416
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• 2017

In order that multiple wideband RF transmitters which have mission to deliver essential information to aircraft operate at the same time, RF transmitter has a variable sub-carrier frequency to modulate the signal. In case of exposure to weak environment, Wide-band RF transmitter is designed to check component of transmitter that includes antenna BIT to increase system reliability. Normally, Antenna BIT measure the reflection RF power of antenna to check system condition. However, Antenna BIT has a difference that depends on testing frequency to use the long RF cable which is located between the power amp and the antenna. The periodic phenomenon of the reflected antenna power are theoretically explained about dependence on the RF cable length. Based on presented result, suggested measurement methods is effectively able to be applied to diagnosis system condition.