QQ客服 官方微博 反馈留言

浏览/检索结果: 共6条，第1-6条 帮助 限定条件 专题：长春光学精密机械与物理研究所    第一署名单位    第一作者单位    通讯作者单位     已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 OFDM baseband modulation technology based on VHDL (EI CONFERENCE) 会议论文 2010 IEEE International Conference on Advanced Computer Control, ICACC 2010, March 27, 2010 - March 29, 2010, 445 Hoes Lane - P.O.Box 1331, Piscataway, NJ 08855-1331, United States Lin L.; Qiao Y.-F.; Su W.-X. 收藏  |  浏览/下载：10/0  |  提交时间：2013/03/25 In order to improve the transmission velocity in mulitipath fading wireless channel  two main advantages are obtained via discussing spectrum utilization ratio of OFDM. Then  the high speed OFDM technology receives increasing attentions in mobile communication. Modulation programs are designed with VHDL based on the principle of OFDM in the paper. First  from the results of VHDL simulation  after OFDM fundamental is introduced  the realization of baseband operations  such as interleaver  subcarrier modulation  IFFT and adding CP  are presented. Finally  implemented programs are validated on the actual implement system. Experimental results indicate that setup time corresponding to transmission velocity is only 71.05s and steady time is approximately 6 times as setup time  that is  not only achieving the high speed transmission  but also supplying adequate modulation time. 2010 IEEE.   Estimation algorithm of mobile OFDM CFOs based on step-size (EI CONFERENCE) 会议论文 2009 International Conference on Information Engineering and Computer Science, ICIECS 2009, December 19, 2009 - December 20, 2009, Wuhan, China Lin L.; Qiao Y.-F.; Su W.-X. 收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25 In order to maintain orthogonality among subcarriers for mobile OFDM  a CFOs step-size estimation model is established to avoid severe performance degradation caused by ICI  and algorithmic stability  step-size parameter  the error of CFOs estimate and etc are investigated. First  after an averaging window algorithm is introduced  the mathematic model of step-size estimation algorithm is obtained through step-size parameter and time-varying CFOs. Then  based on the results of MATLAB simulation  the determination of step-size parameter  the advantages of step-size algorithm and precision are discussed. Finally  time sequence plots of added CP  interleaver and subcarrier modulation with VHDL are presented. Experimental results indicate that the maximum of CFOs errors is 0.00987 in 3 variance interval  when mobile velocity is 400 km/h  according with verdicted principle that in order for the ICI effects to be negligible  the error of CFOs estimation must be accurate within 1-2% of the subcarrier spacing  and programs can correctly implement on circuit board. 2009 IEEE.   光学梳状滤波器技术研究 学位论文 博士, 长春光学精密机械与物理研究所: 中国科学院长春光学精密机械与物理研究所, 2004 邵永红 收藏  |  浏览/下载：34/0  |  提交时间：2012/03/21 光学梳状滤波器  密集波分复用器  光器件  滤波器   光波分复用器件和光学梳状滤波器理论及最新进展 期刊论文 光机电信息, 2002, 期号: 05, 页码: 25-28 邵永红; 姜耀丽; 钱龙生 收藏  |  浏览/下载：13/0  |  提交时间：2013/03/11 Interleaver:6600  光学梳状滤波器:5622  波分复用器件:3020  Bragg光纤光栅:2536  介质薄膜滤波器:1661  信道间隔:1418  平面波导:1223  多波长:1007  城域网:1004  插入损耗:981   Research of a novel Interleaver basing on modified Michelson interferometer with three-mirror Fabry-Perot interferometer and Gires-Tournois resonator 会议论文 2002 Shao Y. H.; Jiang Y. L.; Zheng Q. A.; Qian L. S. 收藏  |  浏览/下载：8/0  |  提交时间：2013/03/28 Research of a novel interleaver basing on modified Michelson interferometer with three-mirror Fabry-Perot interferometer and Gires-Tournois resonator (EI CONFERENCE) 会议论文 APOC 2002:Optical Components and Transmission Systems, October 16, 2002 - October 18, 2002, Shanghai, China Shao Y.; Jiang Y.; Zheng Q.; Qian L. 收藏  |  浏览/下载：11/0  |  提交时间：2013/03/25 A novel Interleaver using a modified Michelson interferometer in which its reflecting mirrors are replaced by three-mirror Fabry-Perot interferometer and Gires-Tournois resonator respectively is presented. On basis of the theory of Michelson interference  a designing principle of the interleaver  which has square-like frequency response with zero ripple  wide flat-top  unity contrast  simple structure  and stable performance  is given. The device which possesses channel spacing of 50 GHz  zero ripple  0.5 dB bandwidth more than 0.27 nm  and close channel isolation more than 73 dB has been designed.