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无系统误差的CPⅢ精密三角高程控制网仿真研究 被引量:7
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作者 李建章 《测绘工程》 CSCD 2019年第6期1-5,共5页
利用精密三角高程测量代替精密水准建立CPⅢ高程控制网将大大提高CPⅢ控制网建网的速度。然而由于大气折光、地球曲率以及垂线偏差等系统性误差的影响,CPⅢ精密三角高程控制网的精度通常难以完全满足规范的要求。文中通过仿真数据对无... 利用精密三角高程测量代替精密水准建立CPⅢ高程控制网将大大提高CPⅢ控制网建网的速度。然而由于大气折光、地球曲率以及垂线偏差等系统性误差的影响,CPⅢ精密三角高程控制网的精度通常难以完全满足规范的要求。文中通过仿真数据对无系统误差CPⅢ精密三角高程控制网进行了研究,得出如下结论:CPⅢ精密三角高程控制网在仅受到偶然误差的影响下,其相邻点间高差中误差可以达到0.15 mm以下;采用增加测回数、提高基准点密度以及限制控制网长度等手段对于提高控制网精度影响甚微。因此,进一步提高CPⅢ精密三角高程控制网的精度,需要从解决系统误差着手。 展开更多
关键词 CPⅢ高程控制网 精密三角高程 仿真研究 无系统误差
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PCCC for the performance improvement of the wireless optical communication system 被引量:2
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作者 REN Rui-xiang LI Xiao-feng LIN Mi 《Optoelectronics Letters》 EI 2006年第2期133-135,共3页
In wireless optical communication, effects of scintillation make average Bit Error Rate (BER) deteriorate. To improve system performance,PCCC (Parallel Concatenated Convolutional Code) encoding scheme is employed,... In wireless optical communication, effects of scintillation make average Bit Error Rate (BER) deteriorate. To improve system performance,PCCC (Parallel Concatenated Convolutional Code) encoding scheme is employed,and upper bound on the bit error rate is given by considering the effects of scintillation,APD noise and thermal noise. Simulation results show that the POOC encoding scheme can relieve turbulenceinduced intensity fluctuations and the system performance is improved remarkably. 展开更多
关键词 无线通信 光学通信系统 PCCC 误差
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Complexity-reduced ICI cancellation for OFDM system over doubly-selective channels 被引量:1
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作者 席晓平 Zhang Can 《High Technology Letters》 EI CAS 2009年第2期181-186,共6页
In doubly-selective fading wireless channel, the conventional orthogonal frequency division multi-plexing (OFDM) receivers for inter-cartier interference (ICI) compensation require extensive computations. To obtai... In doubly-selective fading wireless channel, the conventional orthogonal frequency division multi-plexing (OFDM) receivers for inter-cartier interference (ICI) compensation require extensive computations. To obtain an effective balance between performance and complexity, the whole channel response matrix was decomposed into a sequence of submatrix, and then a novel equalizer based on minimum mean square error (MMSE) criterion was presented to combat the ICI. Furthermore, a simple ordering-based decision-feedback equalizer (DFE) Was derived to exploit the temperal diversity gain offered by mobile channels. Numerical studies illustrate that although the MMSE equalizer still suffers from error floor, whereas the DICE equalizer exhibits significant performance improvement. The advantage of the proposed scheme indicates its potential applications in the future broadband wireless systems. 展开更多
关键词 doubly-selective fading orthogonal frequency division multiplexing (OFDM) intercarrier interference (ICI) EQUALIZATION channel estimation
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