Energy detection of partially polarized radio signals against the background of Gaussian noise

We propose a structural diagram of the energy receiver of partially polarized radio signals. Analytical expressions for characteristics of the energy detection of partially polarized radio signals against the background of Gaussian noise are obtained. The behavior of these characteristics in various cases is analyzed.     

Characteristics of the energy detection of unknown radio signals against the background of Likhter noise

We analyze operation of the energy detector in the case of a non-Gaussian noise background. Analytical expressions for the probabilities of correct detection and false alarm of the energy detector receiving unknown signals against the background of Likhter noise are obtained. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 10, pp. 889–898, October 2008.     

Optimum reception of a signal with unknown duration against the background of white noise

An algorithm for optimum (Bayesian) detection and measurement of the duration of a rectangular pulse observed against the background of white Gaussian noise is developed. The potential characteristics of reception are obtained as a result of computer modeling of the synthesized algorithms. State University, Voronezh, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 40, No. 12, pp. 1531–1541, December, 1997.     

Detection of an ultra-wideband quasi radio signal against background random noise

We perform synthesis and analysis of the maximum-likelihood detector of an ultra-wideband quasi radio signal whose duration may amount to several periods or even a fraction of a period of harmonic oscillation with unknown amplitude and phase. Characteristics of the classical quadrature detector on receipt of the ultra-wideband quasi radio signal are found. Applicability conditions of the model of a narrow-band radio signal for solving the detection problem to specified accuracy are formulated.     

Detection of an ultra-wideband quasi-radio signal with unknown arrival time against the background of white noise

We synthesize and analyze the maximum-likely detector of an ultra-wideband quasi-radio signal whose duration can be several periods or even a part of the period of harmonic oscillation with unknown amplitude, phase, and arrival time. Characteristics of the classical quadrature detector during reception of an ultra-wideband quasi-radio signal are found. The results of statistical simulation of detection algorithms are presented.     

Detecting and filtering a flow of different pulsed signals against the noise background

We consider the problem of separate detection and filtration of a flow of pulsed signals. We assume that statistically independent pulsed signals of different shape and random amplitude appear randomly against the background of noise. An algorithm for estimation of the detection probability of each signal is obtained. Recurrent expressions for thea posteriori probability density of each signal are found. The results of numerical simulation of the proposed algorithms of signal processing are presented. Lobachevsky State University of Nizhny Novgorod Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 1, pp. 92–100, January, 1999.     

Parametric identification of ultrabandwidth signals on the background of noise

Parametrization algorithms have been developed for solving the problem of time and frequency identification of ultrabandwidth signals. In the time domain, a signal is represented as a sequence of rectangles with the height corresponding to the signal average level within the chosen time lobe. The height and position of rectangles on the time axis are used as parameters for signal identification. In the frequency domain, a signal is represented as a sectionally continuous complex spectrum. The amplitude and complex spectra used for identification are represented by a finite number of values which is considerably smaller than that of the initial sample. The algorithms were checked for operability by performing numerical simulations with a code developed for the calculation of fields by the finite difference time domain method. The results are presented as identification probability diagrams. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 46–53, June, 2008.     

高荧光及强背景噪声情况下表面增强拉曼散射光谱提取方法研究

试提出一种高荧光及强背景噪声情况下表面增强拉曼散射光谱的提取方法。该方法从分析荧光谱及背景噪声信号的组成入手,构建相应模型对荧光谱及噪声信号进行估计,通过比较估计结果与实际数据的差别识别谱峰信号,并定位谱峰的基底位置。通过在若丹明6G、前列腺特异抗原测量及pH值传感实验中的实际应用检验可知,该方法可提高表面增强拉曼散射光谱信号的分辩率和测量准确度,在微量物质鉴别及物质含量定量测量方面有较好的应用前景。     

一种检测低信噪比下未知波形时变相干信号的方法*

从获取的数据中检测目标信号,是雷达、声呐等领域重要的研究内容。时频域严重畸变的回波信号以及时变线谱信号的自适应检测,具有重要意义。为了挖掘和推广自适应相干累积（Adaptive Coherent Integration,ACI）技术在未知时变信号检测领域的能力,本文给出了ACI算法的基本原理,并进行了系统性地理论推导,得到了ACI算法的宽带时变自回归滑动平均模型（ARMA）和窄带复解析模型。利用这些模型解释了产生信号相干累积的机理,分析得出了产生相干累积的条件,揭示了这种时变系统的许多奇异特性。结合仿真实验和实际海上实验数据对ACI算法展开验证,结果表明ACI算法对于低信噪比下未知波形信号具有优异的检测能力,展示出ACI算法在水下探测等相关领域存在广泛的实际应用前景。     

Maximum likelihood method in the problem of adaptive detection of signals with unknown noninformative parameters

A new algorithm of signal detection is synthesized with an estimate of signal noninformative parameters against the noise background with an arbitrary distribution law. It has been shown by a simple example of Gaussian clutter that the efficiency of the synthesized detector approaches the efficiency of deterministic signal detection. Antiaircraft Command High School of Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No, 5, pp. 640–650, May, 1998.     

Detection of weak signals against the background of active noise fields scattered in an inhomogeneous medium. II. General case

In this paper, we study the specifically nonlinear functions of a detector, which are required for the non-Gaussian law of distribution of scattered noise. Antiaircraft Command High School, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 10, pp. 1314–1325, October 1998.     

Detection of weak signals against the background of artificial noise fields scattered by an inhomogeneous medium. I. Gaussian approximation

We consider an optimal procedure for weak signal detection against the background of scattered artificial noise fields within the framework of a Gaussian approximation. We focus on the specific problems of detection and adaptive recovery of the primary wave field at the inputs of a multichannel detector. Antiaircraft Command High School, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 9, pp. 1177–1194, September, 1998.     

Detection of weak useful signals on the background of noise in atomic absorption spectroscopy

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 56, No. 3, pp. 467–473, March, 1992.     

Method for determination of the intensity of cosmic radio sources surrounded by an irregular background

We consider a method for taking into account the irregularity of distributed cosmic radiation in measurement of the antenna-temperature increment when the antenna is pointed successively at the source and a reference area. A procedure and algorithms for processing observational data that make it possible to improve the accuracy and standardize the measurement procedure are described. The results of a test of this method at a frequency of 575 MHz using four of the most powerful discrete radio sources are reported.Radiophysical Research Institute, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 11, pp. 1158–1167, November, 1995.     

Compressive sampling based differential detection for UWB impulse radio signals

Noncoherent detectors significantly contribute to the practical realization of the ultra-wideband (UWB) impulse-radio (IR) concept, in that they allow avoiding channel estimation and provide highly efficient reception capabilities. Complexity can be reduced even further by resorting to an all-digital implementation, but Nyquist-rate sampling of the received signal is still required. The current paper addresses this issue by proposing a novel differential detection (DD) scheme, which exploits the compressive sampling (CS) framework to reduce the sampling rate much below the Nyquist-rate. The optimization problem is formulated to jointly recover the sparse received signal as well as the differentially encoded data symbols, and is compared with both the separate approach and the scheme using the compressed received signal directly, i.e., without reconstruction. Finally, a maximum a posteriori based detector using the compressed symbols is developed for a Laplacian distributed channel, as a reference to compare the performance of the proposed approaches. Simulation results show that the proposed joint CS-based DD brings the considerable advantage of reducing the sampling rate without degrading the performance, compared with the optimal MAP detector.