Research On Cooperative Spectrum Sharing Strategy Based On Energy Efficiency And Spectrum Efficiency

The high energy consumption and exponential growth in wireless communication networks face serious challenges to the design of more energy efficiency and spectrum efficiency green communications that should deal with the scarcity of radio resources.A promising approaches technique called cognitive radio networks(CRNs)is proposed as a key design to improve spectral efficiency of communication systems.So that,on premise of guaranteeing the normal work of primary user,under the premise that the normal work of the primary user is guaranteed,spectrum sharing,which can allow primary and secondary users to coexist in the open licensed frequency band,has become a research hotspot in the cognitive radio system.In this paper,the spectrum sharing platform is based on the energy efficiency and the spectrum efficiency.The relationship between performance of cooperative spectrum sharing system and secondary users selection,cooperative modes selection and power allocation of secondary user and so on is researched.Finally,a green and efficient cooperative spectrum sharing strategy is designed and implemented.Firstly,the key technologies in cognitive radio networks are studied.Spectrum sharing system architecture and technology classification are summarized.Then several cooperative schemes in cooperative spectrum sharing technology are analyzed.Next,this paper studies fractional Fourier transform(Fr FT)technology and verified the signal energy accumulation property of Chirp signals in the Fr FT domain.At last,common optimization algorithms for energy efficiency and spectrum efficiency are briefly introduced.Then we design the cooperative spectrum sharing strategy based on the energy efficiency and spectrum efficiency with the given statistics of channel gain.In our proposed strategy,firstly select the optimal secondary user for maximizing the system spectrum efficiency,which can adaptively select appropriate cooperation scheme according to the channel conditions to assist primary user meeting its communication performance requirements.Then the power allocation optimization based on the statistics of channel gain is analyzed to maximize energy efficiency of the secondary system while guaranteeing the outage probability constraint of primary system.Simulation results show that,the interference to the primary users can be greatly reduced.Higher energy efficiency of secondary system and higher system spectrum utilization can be realized while guaranteeing the communication requirements of the primary system in our proposed strategy.Moreover,with the increase of secondary user number,the performance of both outage performance and achievable data rate is significantly improved for the secondary system.Finally,given the time-varying characteristic of wireless channel,we propose a cooperative spectrum sharing strategy based on the energy efficiency and spectrum efficiency with the given instantaneous channel gain furtherly.In our proposed strategy,cosine signal and Chirp signals are adopted for primary user and secondary users,respectively.Moreover,the joint optimization of the distributed secondary users selection for maximizing the system spectrum efficiency and the power allocation for maximizing the energy efficiency of secondary users are studied to achieve the spectrum sharing performance improvement while guaranteeing the target data rate of primary user.Simulation results show that under the proposed strategy,the interference to the primary users can be greatly reduced.The outage probability of both primary and secondary systems can be improved.The energy efficiency of the secondary system and the system spectrum efficiency can be improved significantly.