I got concludes that in engine field , the error differentiation ratio of the first year before crises is 3 . 3 and the error ration of the second year is 11 . 7 in and the error ration of the third year is 16 . 7 ; in real estate , the error ratio is 3 . 3 in the first year , and 10 in the second year ; chemistry industry is 0 in the first year and the error ratio of the second year is 9 . 375 , the forecast ratio of the third year is 12 . 9 ( 3 )在化工行业预警模型中,在财务危机发生之前的第1年模型误判率为0 ,第2年误判率为9 . 375 ,第3年误判率为12 . 9 。在st发生的前三年里,化工行业的模型误判率都在15以内,机械设备行业的模型误判率都在17以内,大大提高了模型的判别准确率。
Design a kind of sub - optimum digital prefilter . through the simulation of timing recovery loop which is n ' t added prefilter and which is added prefilter , discuss the convergence characteristic and compare the relation between timing jitter and signal to noise ratio , the relation between timing jitter and noise bandwidth of loop , the relation between symbol error ratio and signal to noise ratio 通过对加预滤波器后的定时恢复环的仿真,讨论了环路的收敛情况,比较了所设计的数字预滤波器和无预滤波器时环路定时抖动与信噪比、定时抖动与环路噪声带宽、误码率与信噪比的数量关系,证实所设计的数字预滤波器对减少定时抖动非常有效。
Afterwards the principle and characteristics of can technology are expatiated and cals are briefly introduced , followed by a research on the reliability and real - time performance of can , which indicates that can has a very low error ratio and that it is possible to design a can system meeting the requirements of industry control 然后文章分析了can总线的技术原理,介绍了can高层协议,深入研究了can在可靠性和实时性等方面的性能,结果表明, can具有极低的出错概率,设计一个实时性满足工业控制的can总线系统是可行的。
In order to practice the sess communication system based on ar filter , the system must have the good performance of anti - jamming and multiple accessing . we analyze and simulate the ar - sess communication model , the important performance factors , the bit error ratio ( ber ) performance and the multiple accessing 本文以ar自编码直接序列扩频通信方式为对象,讨论基于ar的自编码扩频通信系统( ar - sess )模型、影响ar - sess系统性能的重要因素、 ar - sess通信的信噪比和多址通信能力。
With the established rf front - end system simulation platform , adding the digital modulated baseband signal , this paper simulated the multifold digital modulated signal ’ s transmission , such as 2ask , qpsk , and 16qam . then researches of power compression and phase noise of local oscillation influence the bit error ratio for different modulated system . the designing is satisfied multifold functions request with the high - powered and integrated broadband rf front - end 随后在建立的宽带射频前端通用仿真平台上,加入基带数字调制信号,对多种数字调制格式的信号在该通用平台上的传输作了研究,模拟了2ask 、 qpsk和16qam等调制格式信号的发射与接收,研究了功率压缩和本振相位噪声对不同调制的误码率影响,实现了满足多种功能要求的宽带高性能综合射频前端的设计。
In mobile communication and high - speed wireless digital communication , multi - path , the finity of channel bandwidth and faultiness of the channel , lead to the bringing of intersymbol interference ( isi ) when data transfer . this is an important factor that degrades the performance of communication . however channel equalization technique can eliminate the isi and noise , it can also reduces the bit error ratio 在移动通信及高速无线数据通信中,多径效应和信道带宽的有限性以及信道特性的不完善性导致数据传输时不可避免地产生码间干扰( isi ) ,成为影响通信质量的重要因素,而信道的均衡技术可以消除码间干扰和噪声,并减少误码率。
This article proposes the adaptive algorithm based on equal snr signal noise ratio , and applies it in adaptive ofdm system . in frequency selective fading channel , compared with the traditional ofdm system based on equal power allocation , the system outperforms in ber bit error ratio performance 提出了一种基于最小平均误码率的自适应预处理算法,并将该算法应用于自适应ofdm系统,在频率选择性衰落信道条件下,与等功率分配的ofdm系统相比,误比特性能有了很大程度的提高。
The nonlinear filtering for nbi estimate - subtract assumes that the prediction error is dominated by spread spectrum signal and the background noise power is far below spread spectrum chip power , this assumption promises the low error ratio of chip decision but may not be attainable to digitalized dsss receiver in military communication environment , and does not coincide with the principle of dsss communication that decreases bit error ratio ( ber ) depending on spread spectrum gain , not on chip power 在干扰估计抵消滤波中,以往的非线性滤波要求干扰抵消滤波后扩频信号功率远大于残余噪声功率,进而假设码片判决的误码片率基本为零,这一要求对军用扩频通信是不利的,而且也不符合扩频通信利用扩频增益降低误码率的原则。