An active reflector is one of the key technologies for constructing large telescopes, especially for millimeter/sub-millimeter radio telescopes. This article in- troduces a new efficient laser angle metrology system f...An active reflector is one of the key technologies for constructing large telescopes, especially for millimeter/sub-millimeter radio telescopes. This article in- troduces a new efficient laser angle metrology system for an active reflector antenna on large radio telescopes. Our experiments concentrate on developing an active reflec- tor for improving the detection precisions and the maintenance of the surface shape in real time on the 65-meter prototype radio telescope constructed by Nanjing Institute of Astronomical Optics and Technology （NIAOT; http：//65rn.shao.cas.cn/）. The test results indicate that the accuracy of the surface shape segmentation and maintenance has the dimensions of microns, and the time-response can be on the order of minutes. Our efforts proved to be workable for sub-millimeter radio telescopes.展开更多
In this article, an adaptive radio resource ＂allocation algorithm applied to multiple traffic orthogonal frequency division multiple access （OFDMA） system is proposed, which distributes subcarriers and bits among u...In this article, an adaptive radio resource ＂allocation algorithm applied to multiple traffic orthogonal frequency division multiple access （OFDMA） system is proposed, which distributes subcarriers and bits among users according to their different quality of service requirements and traffic type. By classifying and priorifizing the users based on their traffic characteristic and ensuring resource for higher priority users, the new scheme decreases tremendously the outage probability of the users requiring a real-time transmission without impact on the spectrum efficiency of system, as well as the outage probability of data users is not increased compared with the radio resource allocation methods published.展开更多
This paper proposes and analyzes a downlink multi-carrier proportional fair scheduler and an adaptive radio resource allocation algorithm combining the scheduler. This scheduler and algorithm are suitable for orthogon...This paper proposes and analyzes a downlink multi-carrier proportional fair scheduler and an adaptive radio resource allocation algorithm combining the scheduler. This scheduler and algorithm are suitable for orthogonal frequency division multiple access wireless communication systems supporting multiple quality of service classes. Our results demonstrate that the scheduler and algorithm provide user-explicit fairness with user-individual quality of service guarantees, but the joint schheme achieves a higher sum-rate capacity with flexible parameter settings compared with the multi-carrier proportional fair scheduler.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos. 10703008,11073035 and 10833004)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KJCX2-YW-T17)
文摘An active reflector is one of the key technologies for constructing large telescopes, especially for millimeter/sub-millimeter radio telescopes. This article in- troduces a new efficient laser angle metrology system for an active reflector antenna on large radio telescopes. Our experiments concentrate on developing an active reflec- tor for improving the detection precisions and the maintenance of the surface shape in real time on the 65-meter prototype radio telescope constructed by Nanjing Institute of Astronomical Optics and Technology （NIAOT; http：//65rn.shao.cas.cn/）. The test results indicate that the accuracy of the surface shape segmentation and maintenance has the dimensions of microns, and the time-response can be on the order of minutes. Our efforts proved to be workable for sub-millimeter radio telescopes.
基金the National Natural Science Foundation of China （60472070） the Key Project of Chinese Ministry of Education （105035） the Specialized Research Fund for the Doctoral Program of Higher Education （20050013005）.
文摘In this article, an adaptive radio resource ＂allocation algorithm applied to multiple traffic orthogonal frequency division multiple access （OFDMA） system is proposed, which distributes subcarriers and bits among users according to their different quality of service requirements and traffic type. By classifying and priorifizing the users based on their traffic characteristic and ensuring resource for higher priority users, the new scheme decreases tremendously the outage probability of the users requiring a real-time transmission without impact on the spectrum efficiency of system, as well as the outage probability of data users is not increased compared with the radio resource allocation methods published.
文摘This paper proposes and analyzes a downlink multi-carrier proportional fair scheduler and an adaptive radio resource allocation algorithm combining the scheduler. This scheduler and algorithm are suitable for orthogonal frequency division multiple access wireless communication systems supporting multiple quality of service classes. Our results demonstrate that the scheduler and algorithm provide user-explicit fairness with user-individual quality of service guarantees, but the joint schheme achieves a higher sum-rate capacity with flexible parameter settings compared with the multi-carrier proportional fair scheduler.
