Cooperative spectrum sharing of multiple primary users and multiple secondary users

This paper proposes a multiple-input multiple-output （MIMO） based cooperative dynamic spectrum access （DSA） framework that enables multiple primary users （PUs） and multiple secondary users （SUs） to cooperate in spectrum sharing. By exploiting MIMO in cooperative DSA, SUs can relay the primary traffic and send their own data at the same time, which greatly improves the performance of both PUs and SUs when compared to the non- MIMO time-division spectrum sharing schemes. Especially, we focus on the relay selection optimization problem among multiple PUs and multiple SUs. The network-wide cooperation and competition are formulated as a bargaining game, and an algorithm is developed to derive the optimal PU-SU relay assignment and resource allocation. Evaluation results show that both primary and secondary users achieve significant utility gains with the proposed framework, which gives all of them incentive for cooperation.

Cooperative Anti-Interference Spectrum Sharing with Secondary User Selection

In this paper, we propose a cooperative anti-interference spectrum sharing strategy with secondary user selection where the secondary system can gain spectrum access along with the primary system. Specifically, secondary user and are selected to transmit the primary and secondary signal through different bandwidth in the second transmission slot which occupies fraction of the time. Thus, the primary and secondary systems will not interfere with each other. We study the joint optimization of time and bandwidth allocation such that the transmission rate of the secondary system is maximized, while guaranteeing the primary system to achieve its target rate. Simulation results confirm efficiency of the proposed spectrum sharing strategy, and the significant performance improvement of the cognitive system.

Trading platform for cooperation and sharing based on blockchain within multi-agent energy internet

With the release of the electricity sales side,large-scale small-capacity distributed power generation units are connected to the distribution side,forming multi-type market entities such as microgrids,integrated energy systems,and virtual power plants.With the large-scale integration of distributed energy,the energy market under the energy internet is different from a traditional transmission grid.It is currently developing in the direction of diversified entities and commodities,a flat structure,and a flexible and competitive multi-agent market mechanism.In this context,this study analyzes the value of combining blockchain and the electricity market presents the design of a blockchain trading framework for multi-agent cooperation and sharing of the energy internet.The nodes in market transactions are modeled through power system modeling in the physical layer and the transaction consensus strategy in the cyber layer;moreover,the nodes are verified in a modified IEEE 13 testing feeder of a distribution network.A transaction example is demonstrated using the multi-agent cooperation and sharing transaction platform based on the Ethereum private blockchain.

Land System Adjustment in Process of Developing Modern Agriculture

Under the premise of unchanging the collective ownership and the mode of family business, China should choose land shares pack system as the goal pattern of farmland system innovation. It is hoped that the pattern is accepted and supported by both sides of the government and the farmers, and then it constructs the land reasonable circulation and the effective centralism mechanism, thus realizing smooth transition from the traditional agriculture to the modem agriculture.