In downlink cellular multiple users in multiple cells systems using beams, the should cooperate to generate beams to improve the spectrum efficiency. A mathematical model for the multi-cell multi-user downlink transm...In downlink cellular multiple users in multiple cells systems using beams, the should cooperate to generate beams to improve the spectrum efficiency. A mathematical model for the multi-cell multi-user downlink transmission is established, and the gradients of the variables including beamfonning filters, receiving filters and transmitting power are calculated. Then, a gradient-project-based cooperative beamforming scheme is proposed in which each user iteratively adjusts bearnforming variables in the direction of the gradients and projects onto feasible spaces. The information exchange protocol needed to support the scheme is also described. Simulation results show that the proposed scheme can achieve an average spectral efficiency of about 5 bit/（ s · Hz · cell）. The results show that cooperative beamforming can improve the spectrum efficiency of the cellular systems.展开更多
The efficiency of any organizations at manufacturing sector or service sector, profit making or non-profit making, is most important factor for survival and growth of the organization. The Data Envelopment Analysis （...The efficiency of any organizations at manufacturing sector or service sector, profit making or non-profit making, is most important factor for survival and growth of the organization. The Data Envelopment Analysis （DEA） technique is one of the most popular and effective tool to measure relative efficiency hence is appropriate to make comparison among similar organizations with multiple output and input. This study performs frontier analysis and measures the relative efficiency of Nepalese commercial banks using DEA approach with two output and two input variables.展开更多
基金The National Natural Science Foundation of China(No.61001103)the National Science and Technology Major Project of China (No.2008ZX03003-005)the National Basic Research Program ofChina(973 Program) (No.2007CB310603)
文摘In downlink cellular multiple users in multiple cells systems using beams, the should cooperate to generate beams to improve the spectrum efficiency. A mathematical model for the multi-cell multi-user downlink transmission is established, and the gradients of the variables including beamfonning filters, receiving filters and transmitting power are calculated. Then, a gradient-project-based cooperative beamforming scheme is proposed in which each user iteratively adjusts bearnforming variables in the direction of the gradients and projects onto feasible spaces. The information exchange protocol needed to support the scheme is also described. Simulation results show that the proposed scheme can achieve an average spectral efficiency of about 5 bit/（ s · Hz · cell）. The results show that cooperative beamforming can improve the spectrum efficiency of the cellular systems.
文摘The efficiency of any organizations at manufacturing sector or service sector, profit making or non-profit making, is most important factor for survival and growth of the organization. The Data Envelopment Analysis （DEA） technique is one of the most popular and effective tool to measure relative efficiency hence is appropriate to make comparison among similar organizations with multiple output and input. This study performs frontier analysis and measures the relative efficiency of Nepalese commercial banks using DEA approach with two output and two input variables.
