An interference alignment(IA)spectrum sharing method based on Rayleigh quotient is proposed for distributed multi-user multi-antenna cognitive radio(CR) networks.The interference from cognitive users(CUs)to the primar...An interference alignment(IA)spectrum sharing method based on Rayleigh quotient is proposed for distributed multi-user multi-antenna cognitive radio(CR) networks.The interference from cognitive users(CUs)to the primary(PR) system is constrained through the Rayleigh quotients of channel matrices to deal with the absence of PR users(PUs) in the IA process.As a result,the IA scheme can be applied in CR networks without harmful interference to PUs.Compared with existing IA based spectrum sharing methods,the proposed method is more general because of breaking the restriction that CUs can only transmit on the idle sub-channels of the PR system.Moreover,in comparison to other four spectrum sharing methods applicable in general scene,the proposed method leads to improved performance of achievable sum rate of the CR system as well as guarantees the transmission of PUs.展开更多
In Bangladesh, more than a dozen of private TV channels are operating and about 10 new channels are waiting with green signal for transmission. Bangladesh Television （BTV）, the only government owned and administered...In Bangladesh, more than a dozen of private TV channels are operating and about 10 new channels are waiting with green signal for transmission. Bangladesh Television （BTV）, the only government owned and administered, and known as structurally a biased institution serves the audience the public service information most. At the same time it serves purposes of incumbent government. Public information （PI） broadcast means broadcasting towards public welfare which may bring about change in the betterment of life and work of people. Its main focus would be on information, education, and motivation values rather than entertainment. In case of information, dissemination, and documentation, all private TV channels in Bangladesh serve more entertainment and less public service information, whereas, BTV＇s focus is evident on more PI. The owners and operators of private channels think first of their business profit as well as pressure from government and political parties. During formulating planning and strategies or building program content, they become cautious as they fear that the government become angry and shut down the channel.展开更多
基金supported by National Natural Science Foundation of China under Grant 6120123361271262Fundamental Research Funds for the Central Universities (2013G1241114)
文摘An interference alignment(IA)spectrum sharing method based on Rayleigh quotient is proposed for distributed multi-user multi-antenna cognitive radio(CR) networks.The interference from cognitive users(CUs)to the primary(PR) system is constrained through the Rayleigh quotients of channel matrices to deal with the absence of PR users(PUs) in the IA process.As a result,the IA scheme can be applied in CR networks without harmful interference to PUs.Compared with existing IA based spectrum sharing methods,the proposed method is more general because of breaking the restriction that CUs can only transmit on the idle sub-channels of the PR system.Moreover,in comparison to other four spectrum sharing methods applicable in general scene,the proposed method leads to improved performance of achievable sum rate of the CR system as well as guarantees the transmission of PUs.
文摘In Bangladesh, more than a dozen of private TV channels are operating and about 10 new channels are waiting with green signal for transmission. Bangladesh Television （BTV）, the only government owned and administered, and known as structurally a biased institution serves the audience the public service information most. At the same time it serves purposes of incumbent government. Public information （PI） broadcast means broadcasting towards public welfare which may bring about change in the betterment of life and work of people. Its main focus would be on information, education, and motivation values rather than entertainment. In case of information, dissemination, and documentation, all private TV channels in Bangladesh serve more entertainment and less public service information, whereas, BTV＇s focus is evident on more PI. The owners and operators of private channels think first of their business profit as well as pressure from government and political parties. During formulating planning and strategies or building program content, they become cautious as they fear that the government become angry and shut down the channel.
