The performance bound of cognitive radio systems is analyzed.We use opportunistic spectrum effi-ciency(OSE)as the performance metric,and point out that the maximum achievable OSE can be used toevaluate the maximum val...The performance bound of cognitive radio systems is analyzed.We use opportunistic spectrum effi-ciency(OSE)as the performance metric,and point out that the maximum achievable OSE can be used toevaluate the maximum value that the introduction of secondary users can add to the conventional wirelesssystems.Based on assumptions of the PU s traffic model and some reasonable approximations,the ex-pression of OSE is obtained and the maximum achievable OSE is derived by solving an optimization prob-lem.The results are verified by computer simulation.展开更多
In actual implementation of spectrum sharing systems, due to the selfishness of primary users, primary users often refuse the access of secondary users to their licensed spectrum bands even if the access of secondary ...In actual implementation of spectrum sharing systems, due to the selfishness of primary users, primary users often refuse the access of secondary users to their licensed spectrum bands even if the access of secondary users doesn＇t affect their transmission. Aimed at the selfishness problem of primary users, a seller＇s market trading mechanism is introduced which can not only stimulate primary users to tolerate larger interference power but also give the primary users an appropriate compensation at the same time, and which has very important practical significance. Based on the mechanism, the achievable maximal gross profit of secondary users and their optimal power allocation scheme in the Rayleigh fading environment are derived, and the interference price of primary users and the average revenue of secondary users＇ impact on them are also studied. Numerical calculation results are conducted to verify our theoretical results.展开更多
基金Supported by the National Basic Research Program of China (2007CB310608)DoCoMo--Tsinghua Cooperation Project and Tsinghua Basic Research Foundation (JC2007050)
文摘The performance bound of cognitive radio systems is analyzed.We use opportunistic spectrum effi-ciency(OSE)as the performance metric,and point out that the maximum achievable OSE can be used toevaluate the maximum value that the introduction of secondary users can add to the conventional wirelesssystems.Based on assumptions of the PU s traffic model and some reasonable approximations,the ex-pression of OSE is obtained and the maximum achievable OSE is derived by solving an optimization prob-lem.The results are verified by computer simulation.
基金Supported by the National Basic Research Program of China （2007CB307104）, the National Natural Science Foundation of China （60973160）, and the Intematiortal Scientific and Technological Cooperation Program （No. $2010GR0902）.
文摘In actual implementation of spectrum sharing systems, due to the selfishness of primary users, primary users often refuse the access of secondary users to their licensed spectrum bands even if the access of secondary users doesn＇t affect their transmission. Aimed at the selfishness problem of primary users, a seller＇s market trading mechanism is introduced which can not only stimulate primary users to tolerate larger interference power but also give the primary users an appropriate compensation at the same time, and which has very important practical significance. Based on the mechanism, the achievable maximal gross profit of secondary users and their optimal power allocation scheme in the Rayleigh fading environment are derived, and the interference price of primary users and the average revenue of secondary users＇ impact on them are also studied. Numerical calculation results are conducted to verify our theoretical results.
