Optimal linear weighted cooperative spectrum sensing for clustered-based cognitive radio networks

The lack of spectrum resources restricts the development of wireless communication applications. In order to solve the problems of low spectrum utilization and channel congestion caused by the static division of spectrum resource, this paper proposes an optimal linear weighted cooperative spectrum sensing for clustered-based cognitive radio networks. In this scheme, different weight values will be assigned for cooperative nodes according to the SNR of cognitive users and the historical sensing accuracy. In addition, the cognitive users can be clustered, and the users with the better channel characteristics will be selected as cluster heads for gathering the local sensing information. Simulation results show that the proposed scheme can obtain better sensing performance, improve the detection probability and reduce the error probability.

Optimal Linear Weighted Cooperative Spectrum Sensing for Clustered-based Cognitive Radio Networks

The lack of spectrum resources restricts the development of the wireless communication-oriented applications. In order to solve the problems of low spectrum utilization and channel congestion caused by the static division of spectrum resource, cognitive radio is regarded as an effective technology. Cooperative spectrum sensing with multi cognitive users can improve the low detection performance caused by channel fading or shadow effect. However, it also may lead to poor detection accuracy due to poor channel conditions of individual users. In order to solve the above problems, this paper proposes an optimal linear weighted cooperative spectrum sensing for clustered-based cognitive radio networks. In this scheme, different weight values will be assigned for cooperative nodes according to the SNR of cognitive users and the historical sensing accuracy. In addition, the cognitive users can be clustered, and the users with the better channel characteristics will be selected as cluster heads for gathering the local sensing information. Simulation results show that the proposed scheme can obtain better sensing performance, improve the detection probability and reduce the error probability.

Gender, the state, and informal self-employment

Purpose The purpose of this paper is to examine the intersection of formality, informality, structures of power, gender, and social norms in the mobile telecommunication industry in Cameroon, and to investigate the reasons for the over-representation of informal self-employed women at the base of the mobile telecommunication industry in the country. Design/methodology/approach This is a qualitative study using interviews and observations. Findings Cameroon’s mobile telecommunication industry is a “spaghetti bowl” where formality, informality, gender, structures of power, and social norms are intertwined. In Cameroon’s mobile telecommunication industry, there is no static division between formality and informality, rather, there is a connection between formality and informality to ensure the unity and totality of the airtime credit distribution system. Self-employment in the mobile telecommunication industry is gendered. Originality/value Analysing the intersection of gender, class, formality, informality, social norms, and structures of power in the functioning of the mobile telecommunication industry in the Cameroon is original.

Antropologia trychotomiczna Orygenesa

Origen was one of the greatest biblical scholars of the early Church, having written commentaries on most of the books of the Bible. He recognized great au­thority of the scripture. In anthropology he gave attention to the text of saint Paul: “May the God who gives us peace make you holy in every way and keep your whole being – spirit, soul, and body – free from every fault at the coming of our Lord Jesus Christ” (1Thess 5:23). According to this text Origen recognized in hu­man being three elements. He tried to unite trichotomy with a concept of division of human being into two parts: interior and exterior man. Spirit in this concept is soul’s teacher and a special form of participation in the divine being. In a sense spirit is ontological image of God in man and for man it is impossible to lose it. Soul is the center of man in which he makes decisions. Soul was originally cre­ated in close proximity to God, with the intention that it should explore the divine mysteries in a state of endless contemplation. The body unites man with the whole created world and gives him material aspect. Origen’s anthropology is very com­plicated but more dynamic then static division on body and soul. If the soul is go­ing to spirit, it become more spiritual, otherwise if the soul is close to the body, it become more materialistic. In this view without any doubt the human soul is posed between spirit and body and is able to acquiesce the desires of spirit but is able to let itself to be led by carnal desires, too. According to Origen man is body, because is creature, which dies, but through the body is able to communicate with mate­rial world. Man is soul because lives and is able to choose. Man is spirit because is open to God and is able to recognize and love God. Trichotomic anthropology shows that ontological and moral aspects of human being permeate each other and it demonstrates the interior drama and struggle, which always exists in man.