随着科学技术的日益发展,汽车制造行业也逐渐成熟,对于汽车中供电车灯的关注度正在逐步提高,而非接触供电车灯的研究是汽车制造业更为关注的课题。本文对非接触供电车灯的原理以及设计作了较为详细的阐释,并用ARM微处理器作为非接触供...随着科学技术的日益发展,汽车制造行业也逐渐成熟,对于汽车中供电车灯的关注度正在逐步提高,而非接触供电车灯的研究是汽车制造业更为关注的课题。本文对非接触供电车灯的原理以及设计作了较为详细的阐释,并用ARM微处理器作为非接触供电车灯的无线反馈稳压电路的处理单元,利用Protel DXP2004设计出原边和副边的PCB板,采用编程工具Keil u Vison4编写原边电路的发射程序。最后对于这种车灯的性能做出了分析,并预测其将成为汽车行业发展的一种前景。展开更多
Due to the broadcast nature of wireless transmission medium,security threats may hinder propagation of cognitive radio systems for commercial and military data application. This paper sets a channel error analytical f...Due to the broadcast nature of wireless transmission medium,security threats may hinder propagation of cognitive radio systems for commercial and military data application. This paper sets a channel error analytical framework and studies the joint impact of estimation errors and feedback delay on secrecy performance in cognitive radio networks. Under the assumption that system applies beamforming and jamming scheme,a multi-antenna cognitive base station( CBS) sends confidential signals to a secondary user( SU) in the presence of M primary users( PUs) and an eavesdropper. Assuming only imperfect channel state information( CSI) about the receivers is available,secrecy rate,outage probability,secrecy throughput are deduced to obtain a closed-form expression. It is shown that while the transmit power increases,secrecy throughput would reach to a constant. Simulation results show that feedback delay adversely impacts on secrecy rate,connection outage probability and secrecy throughput,while estimation error causes more impact on secrecy outage probability. Furthermore,the secrecy rate could increase progressively with the transmit power only if there exists no feedback delay.展开更多
In limited feedback-based CloudRAN(C-RAN) systems,the inter-cluster and intra-cluster interference together with the quantification error can seriously deteriorates the system spectral efficiency.We,in this paper,prop...In limited feedback-based CloudRAN(C-RAN) systems,the inter-cluster and intra-cluster interference together with the quantification error can seriously deteriorates the system spectral efficiency.We,in this paper,propose an efficient three-phase framework and corresponding algorithms for dealing with this problem.Firstly,a greedy scheduling algorithm based on the lower bound of the ergodic rate is performed for generating an elementary cluster in the first phase.And then the elementary cluster is divided into many small clusters according to the following proposed algorithms based on the short term instantaneous information in the second phase.In the end,based on the limited feedback two zero-forcing(ZF) precoding strategies are adopted for reducing the intra-cluster interference in the third phase.The provided Monte Carlo simulations show the effectiveness of our proposed algorithms in the respect of system spectral efficiency and average user rate.展开更多
文摘随着科学技术的日益发展,汽车制造行业也逐渐成熟,对于汽车中供电车灯的关注度正在逐步提高,而非接触供电车灯的研究是汽车制造业更为关注的课题。本文对非接触供电车灯的原理以及设计作了较为详细的阐释,并用ARM微处理器作为非接触供电车灯的无线反馈稳压电路的处理单元,利用Protel DXP2004设计出原边和副边的PCB板,采用编程工具Keil u Vison4编写原边电路的发射程序。最后对于这种车灯的性能做出了分析,并预测其将成为汽车行业发展的一种前景。
基金Supported by the National Natural Science Foundation of China(No.61371122,61471393)the China Postdoctoral Science Foundation under a Special Financial Grant(No.2013T60912)
文摘Due to the broadcast nature of wireless transmission medium,security threats may hinder propagation of cognitive radio systems for commercial and military data application. This paper sets a channel error analytical framework and studies the joint impact of estimation errors and feedback delay on secrecy performance in cognitive radio networks. Under the assumption that system applies beamforming and jamming scheme,a multi-antenna cognitive base station( CBS) sends confidential signals to a secondary user( SU) in the presence of M primary users( PUs) and an eavesdropper. Assuming only imperfect channel state information( CSI) about the receivers is available,secrecy rate,outage probability,secrecy throughput are deduced to obtain a closed-form expression. It is shown that while the transmit power increases,secrecy throughput would reach to a constant. Simulation results show that feedback delay adversely impacts on secrecy rate,connection outage probability and secrecy throughput,while estimation error causes more impact on secrecy outage probability. Furthermore,the secrecy rate could increase progressively with the transmit power only if there exists no feedback delay.
基金supported by the National Natural Science Foundation of China(NSFC) under Grant(No. 61461136001)
文摘In limited feedback-based CloudRAN(C-RAN) systems,the inter-cluster and intra-cluster interference together with the quantification error can seriously deteriorates the system spectral efficiency.We,in this paper,propose an efficient three-phase framework and corresponding algorithms for dealing with this problem.Firstly,a greedy scheduling algorithm based on the lower bound of the ergodic rate is performed for generating an elementary cluster in the first phase.And then the elementary cluster is divided into many small clusters according to the following proposed algorithms based on the short term instantaneous information in the second phase.In the end,based on the limited feedback two zero-forcing(ZF) precoding strategies are adopted for reducing the intra-cluster interference in the third phase.The provided Monte Carlo simulations show the effectiveness of our proposed algorithms in the respect of system spectral efficiency and average user rate.
