Research On The Technologies Of Spectrum Sensing Based On Energy Efficiency In Cognitive Radio Network

Nowadays the Internet has become more and more popular. As can be seen from the ubiquitous wifi, the spectrum resources increasingly tense. And now most of the spectrums are fixed allocated and authorized to use. Cognitive radio(CR)technology arises at the historic moment.It’s a practical wireless network technology which can solve the problem of spectrum resource shortage. At the same time, because of the lagging battery technology, efficiency problem has caught the attention in the field of academy and the engineering application.The optimization problems of spectrum sensing in CR network based on energy efficiency were investigated in this thesis. Through the joint design of various network parameters, this thesis is to reduce the energy consumed by system, while satisfies the performance of Cognitive radio network. And the joint optimization can be applied to Machine-To-Machine(M2M) communications.This thesis focuses on the following four parts:1、In the channel of single primary user, when Bias risks identified and interference rate controlled below the threshold, the secondary users’ throughput can be calculated according to the false alarm and detection probability. Combined with the power model, an optimal algorithm finally is obtained to solve the optimization problem of energy efficiency model.2、In the channel of multiple primary users, the search-time must be considered. This thesis determines the relationship between average search time and sensing time based on the criterion of high throughput first, then establishes energy efficiency issue of joint optimization of sensing time and CU’s transfering power through the transition probability.3、Taking the maximization of the energy efficiency as the design objective, the sensing time and the number of cooperative SUs are jointly optimized subject to the target detection probability. An algorithm combined with fractional programming is provided to solve this problem.4、This part studies the application of the technology of cognitive radio network in M2 M communication. In the single cell model, the M2 M users multiplex the spectrum of cellular communication. The optimization model of M2 M user’s allocation of transmission power based on energy efficiency is established. Finally, simulation is used to analysis the effectiveness of the proposed method.