Estimation of random errors, which are due to shot noise of photomultiplier tube(PMT) or avalanche photodiode(APD) detectors, is very necessary in lidar observation. Due to the Poisson distribution of incident electro...Estimation of random errors, which are due to shot noise of photomultiplier tube(PMT) or avalanche photodiode(APD) detectors, is very necessary in lidar observation. Due to the Poisson distribution of incident electrons, there still exists a proportional relationship between standard deviation and square root of its mean value. Based on this relationship,noise scale factor(NSF) is introduced into the estimation, which only needs a single data sample. This method overcomes the distractions of atmospheric fluctuations during calculation of random errors. The results show that this method is feasible and reliable.展开更多
In this paper, we investigate the weighted iterative decoding to improve the performance of turbo-polar code. First of all, a minimum weighted mean square error criterion is proposed to optimize the scaling factors(SF...In this paper, we investigate the weighted iterative decoding to improve the performance of turbo-polar code. First of all, a minimum weighted mean square error criterion is proposed to optimize the scaling factors(SFs). Secondly, for two typical iterative algorithms,such as soft cancellation(SCAN) and belief propagation(BP) decoding, genie-aided decoders are proposed as the ideal reference of the practical decoding. Guided by this optimization framework, the optimal SFs of SCAN or BP decoders are obtained. The bit error rate performance of turbo-polar code with the optimal SFs can achieve 0.3 dB or 0.7 dB performance gains over the standard SCAN or BP decoding respectively.展开更多
文章主要基于某型光纤捷联航姿研制过程中出现的转位后纯惯性姿态发散快的问题开展研究,分析定位问题原因,针对光纤陀螺小角速率标度因数存在的非线性特点,通过误差建模及标定补偿技术,提升小角速率标度因数线性度、航姿对准精度及纯惯...文章主要基于某型光纤捷联航姿研制过程中出现的转位后纯惯性姿态发散快的问题开展研究,分析定位问题原因,针对光纤陀螺小角速率标度因数存在的非线性特点,通过误差建模及标定补偿技术,提升小角速率标度因数线性度、航姿对准精度及纯惯性姿态精度,以满足长时间精度保持的系统要求。工程实测数据表明,该标定补偿技术的应用能够使光纤捷联航姿准确测量地球自转角速率,有效减小对准零位误差,提升长期姿态精度,实现优于4 h 0.5°的姿态指标要求。展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB05040300)the National Natural Science Foundation of China(Grant No.41205119)
文摘Estimation of random errors, which are due to shot noise of photomultiplier tube(PMT) or avalanche photodiode(APD) detectors, is very necessary in lidar observation. Due to the Poisson distribution of incident electrons, there still exists a proportional relationship between standard deviation and square root of its mean value. Based on this relationship,noise scale factor(NSF) is introduced into the estimation, which only needs a single data sample. This method overcomes the distractions of atmospheric fluctuations during calculation of random errors. The results show that this method is feasible and reliable.
基金supported by the National Natural Science Foundation of China(No.61671080)the National Natural Science Foundation of China(No.61771066)Nokia Beijing Bell Lab
文摘In this paper, we investigate the weighted iterative decoding to improve the performance of turbo-polar code. First of all, a minimum weighted mean square error criterion is proposed to optimize the scaling factors(SFs). Secondly, for two typical iterative algorithms,such as soft cancellation(SCAN) and belief propagation(BP) decoding, genie-aided decoders are proposed as the ideal reference of the practical decoding. Guided by this optimization framework, the optimal SFs of SCAN or BP decoders are obtained. The bit error rate performance of turbo-polar code with the optimal SFs can achieve 0.3 dB or 0.7 dB performance gains over the standard SCAN or BP decoding respectively.
文摘文章主要基于某型光纤捷联航姿研制过程中出现的转位后纯惯性姿态发散快的问题开展研究,分析定位问题原因,针对光纤陀螺小角速率标度因数存在的非线性特点,通过误差建模及标定补偿技术,提升小角速率标度因数线性度、航姿对准精度及纯惯性姿态精度,以满足长时间精度保持的系统要求。工程实测数据表明,该标定补偿技术的应用能够使光纤捷联航姿准确测量地球自转角速率,有效减小对准零位误差,提升长期姿态精度,实现优于4 h 0.5°的姿态指标要求。
