An upper bound estimate on classification error (Corresp.)

An upper bound estimate on the Bayes misclassification error is derived using a kernel function to estimate probability density functions. As a result of this bound, a relationship between a Euclidean distance and a probability of misclassification is indicated.     

Interpolatory quadrature rules and error rate of digital communication systems

A simple numerical technique is proposed for the construction of the estimate of integrals which represent the average error probability of many digital communication systems. Since these integrals are expressed as the expectation of some function of a random variable, their evaluation can be based on the knowledge of a number of moments of the variable. This is investigated from the viewpoint of discussing an algorithm based on interpolatory quadrature formulas which have equally spaced nodes. An example shows the satisfactory performance of the proposed approach.     

On outage and error rate analysis of the ordered V-BLAST

Outage and error rate performance of the ordered BLAST with more than 2 transmit antennas is evaluated for i.i.d. Rayleigh fading channels. A number of lower and upper bounds on the 1st step outage probability at any SNR are derived, which are further used to obtain accurate approximations to average block and total error rates. For m Tx antennas, the effect of the optimal ordering at the first step is an m-fold SNR gain. As m increases to infinity, the BLER decreases to zero, which is a manifestation of the space-time autocoding effect in the V-BLAST. While the sub-optimal ordering (based on the before-projection SNR) suffers a few dB SNR penalty compared to the optimal one, it has a lower computational complexity and a 3 dB SNR gain compared to the unordered V-BLAST and can be an attractive solution for low-complexity/low-energy systems. Uncoded D-BLAST exhibits the same outage and error rate performance as that of the V-BLAST. An SNR penalty of the linear receiver interfaces compared to the BLAST is also analytically evaluated.     

On the bit error rate of lightwave systems with optical amplifiers

The problem of evaluating the performances of communication systems with optical amplifiers and a wideband optical filter is addressed. Exact probability of error expressions for optical signals in presence of amplifier spontaneous noise and photodetector shot noise are given and compared with those predicted by Gaussian approximations for amplitude shift keying (ASK), frequency shift keying (FSK), or differential phase shift keying (DPSK) modulations, both for ideal photodetectors and for the case where shot noise is significant     

On the rate of convergence of nearest neighbor rules (Corresp.)

An erroneous method for maximizing the projected divergence between two Gaussian multivariate hypotheses appeared in a recent paper. The correct solution is given.     

Software error rate evaluation

An expression for estimating the error rate of computer programs is suggested. It is assumed that the total number of errors in a computer program is proportional to the total number of instructions in the program and errors detected are proportional to remaining errors.     

最佳接收机误码率的两种估算观点

很多教材都是从统计的观点讨论分析了最佳接收机的误码率问题,统计的观点认为信道的噪声是非带限的高斯白噪声,分析的过程也假设接收机非带限。但是从实际和滤波的观点来看,任何形式的接收机都是频带受限的,进入到接收机检测器的噪声频带也会受限。文中基于统计和滤波的观点,讨论了最佳接收机的误码率问题,得出的结论相同,但是分析的过程体现了两者的不同之处,有助于更好的了解数字信号的最佳接收。     

Distribution-free performance bounds with the resubstitution error estimate (Corresp.)

Probability inequalities are given for the deviation of the resubstitution error estimate from the unknown conditional probability of error. The inequalities are distribution free and can be applied to linear discrimination rules, to nearest neighbor rules with a reduced sample size, and to histogram rules.     

ASP程序错误及处理

介绍了ASP程序中常见的三种错误类型,提出了有效防止错误的两个方面及错误处理的三种方法。     

应用支持向量回归估计预测陀螺误差系数

针对目前小样本容量陀螺误差系数预测精度不高的问题,本文将支持向量回归估计引入到陀螺误差系数的预测研究中。通过对某型陀螺某项误差系数的预测,并且对比分析该方法与目前通用的AR模型预测方法的预测效果,结果表明本文采用的支持向量回归估计具有更高的预测精度。     

Sampling theorem for wavelet subspaces: error estimate andirregular sampling

The error estimate is useful in the application of the sampling theorem. For the classical Shannon sampling theorem, various errors are widely studied, but for the sampling theorem in general wavelet subspaces, only the aliasing error is studied. In this paper, we study three other errors: truncation error, amplitude error, and time-jitter error. With the same technique, a result on irregular sampling is improved     

An estimate of the error caused by the plane-wave approximation infree-space dielectric measurement systems

In a free-space measurement system, the electrical constitutive parameters of a plane sheet of material are determined using incident, transmitted and reflected electromagnetic beams. The electrical parameters are almost always obtained from the measured transmission and reflection coefficients using a procedure that approximates each beam as a single plane wave whose wavefront is parallel to the surfaces of the sheet (the plane-wave approximation). A theoretical model is constructed to investigate, in a very general way, the limitations of the plane-wave approximation. The field of the incident beam is taken to be a Gaussian function at the center of the sheet and analytic expressions are obtained for the transmitted and reflected beams using the plane-wave spectrum technique. Power transmission and reflection coefficients are calculated and series expansions of these coefficients are used to determine under what conditions the plane-wave approximation applies. Graphical results are presented to show how the error associated with the plane-wave approximation depends on the various parameters for the problem: electrical size of the beam waist, electrical thickness of the sheet etc     

A constraint-based genetic algorithm approach for mining classification rules

Data mining is an information extraction process that aims to discover valuable knowledge in databases. Existing genetic algorithms (GAs) designed for rule induction evaluates the rules as a whole via a fitness function. Major drawbacks of GAs for rule induction include computation inefficiency, accuracy and rule expressiveness. In this paper, we propose a constraint-based genetic algorithm (CBGA) approach to reveal more accurate and significant classification rules. This approach allows constraints to be specified as relationships among attributes according to predefined requirements, user's preferences, or partial knowledge in the form of a constraint network. The constraint-based reasoning is employed to produce valid chromosomes using constraint propagation to ensure the genes to comply with the predefined constraint network. The proposed approach is compared with a regular GA and C4.5 using two UCI repository data sets. Better classification accurate rates from CBGA are demonstrated.     

存在定时误差的MPSK信号调制方式识别

接收机存在定时误差时,应用高阶累积量进行MPSK信号调制方式识别会引起识别率下降.本文针对这一问题,提出了一种对接收数据进行盲定时估计并通过插值滤波进行定时恢复的算法.仿真结果表明,对插值滤波后的数据进行调制识别,具有良好的分类性能,对定时误差有很强的适应能力.     

Source code error bound in the excess rate region

The problem of encoding a discrete memoryless source with respect to a single-letter fidelity criterion, using a block code of lengthnand rateR, is considered. The probability of error,p_{n}(R,D), is defined to be the minimum probability, over all such codes, that the source will generate a sequence which cannot be encoded with distortionDor less. For sufficiently largeR, thatp_{n}(R,D)decreases doubly exponentially with blocklength,nis shown. It is known thatp_{n}(R,D) = 0for some finiten, denoted byn_{0}(R,D). An upper bound ton_{0}(R,D)is also presented and numerically evaluated. The results derived hold independently of the source statistics. It is shown that a theorem of Omura and Shohara for symmetric sources is a special case of the results herein. Additionally, a useful characterization ofR ast (D)for row-balanced distortion matrices is obtained.     

NCFSK bit error rate in the presence of unsynchronised co-channelinterferers

The bit error rate (BER) of binary non-coherent frequency shift keying modulation in the presence of multiple unsynchronised co-channel interferers (UCCIs) and Gaussian noise is investigated. It is found that the BER with UCCIs is generally lower than that with synchronised co-channel interferers (SCCIs). The difference between UCCI and SCCI signal-to-interference ratios required to achieve the same BER performance (<10^-2) increases with the number of interferers     

一种基于FPGA的高速误码测试仪的设计

误码测试仪是检测通信系统可靠性的重要设备。传统的误码测试仪基于CPLD和CPU协同工作,不仅结构复杂,价格昂贵,而且不方便携带。基于FPGA的高速误码测试仪,采用FPGA来完成控制和测试模块的一体化设计,提高了系统功能扩展性和系统的集成度,使得各个功能模块在不改动硬件电路的情况下可以相应变化。在发送端发送m序列作为测试数据,其测试速率最高可达到155 Mb/s。由于将物理层上的各协议层的功能集中到FPGA内部实现,减少了硬件和软件的设计复杂度,并且缩短了系统的开发的周期,具有可升级的特点。     

一种低误码率的ADS-B接收机的设计

针对广播式自动相关监控（ADS-B）接收机存在高误码率的问题,设计一种基于FPGA的ADS-B接收机,通过ADC电路转换解调后的模拟信号为数字信号,并利用FPGA的并行处理的特点,采用流水线方式处理ADS-B信号;利用有关数字滤波和数字信号提取算法,计算得到ADS-B信息,并经过PL2303HX发送电脑上位机中。实验结果证明,可以较好地完成1090MHz ES ADS-B信号的接收,实现了内部数字信号滤波算法和CRC校验,有效地降低设备的误码率。本文网络版地址：http：//www.eepw. com.cn/article/274749.htm     

Symbol error rate of selection amplify-and-forward relay systems

Cooperative diversity schemes significantly improve the performance of wireless networks by transmitting the same information through several nodes. The amplify-and-forward (AF) relaying method is one of the most attractive cooperative diversity schemes due to its low complexity. Selection AF relaying has recently been proven to achieve the same diversity order as and lower outage probability than all-participate relays. In this letter, we present an asymptotic analysis of the symbol error rates of a selection AF network, and compare it with the conventional all-participate scheme     

Modeling of alpha-particle-induced soft error rate in DRAM

Alpha-particle-induced soft error in 256 M DRAM was numerically investigated. A unified model for alpha-particle-induced charge collection and a soft-error-rate simulator (SERS) was developed. We investigated the soft error rate of 256 M DRAM and identified the bit-bar mode as one of dominant modes for soft error. In addition, for the first time, it was found that trench-oxide depth has a significant influence on soft error rate, and it should be determined by the tradeoff between soft error rate and cell-to-cell isolation characteristics