Artigos de revistas: "Coded waveform"

1

Bharadwaj, N., e V. Chandrasekar. "Phase Coding for Range Ambiguity Mitigation in Dual-Polarized Doppler Weather Radars". Journal of Atmospheric and Oceanic Technology 24, n.º 8 (1 de agosto de 2007): 1351–63. http://dx.doi.org/10.1175/jtech2061.1.

Texto completo da fonte

Resumo:

Abstract This paper evaluates the retrieval of polarimetric variables when phase-coded waveforms are employed to suppress range overlaid echoes. A phase-coded waveform tags transmitted pulses with a phase code and then decodes the received signal to separate the overlaid echoes. Two methods suggested for separating overlaid echoes use random and systematic phase-coding techniques. In this paper, random phase and systematic phase-coded waveforms are evaluated for dual-polarized operation. The random phased-coded and systematic phase-coded waveforms are known to provide fairly good estimates of the Doppler spectral moments. This paper presents results at S band to quantify the performance of phase-coded waveform in retrieving polarimetric variables. It is shown that the polarimetric variables for both strong and weak trip echoes are estimated with acceptable accuracy.

Estilos ABNT, Harvard, Vancouver, APA, etc.

2

Yongqiang, Guo, Wu Yumin e Liu Hui. "Construction of Waveform Library in Cognitive Radar". Polish Maritime Research 24, s2 (28 de agosto de 2017): 22–29. http://dx.doi.org/10.1515/pomr-2017-0060.

Texto completo da fonte

Resumo:

Abstract Based on the thoughts of cognitive radar, Fractional Fourier Transform (FrFT) is used to generate a rotatable waveform libraries of Frank coded/Barker coded waveform in this paper. Then, the ambiguity function is used to analyze the delay resolution, Doppler resolution, delay side-lobe level, and Doppler side-lobe level of the waveform libraries and orthogonality of them is also analyzed. Furthermore, we proved theoretically that there is a fixed coordinate transformation between the waveforms of library and its origin waveform. Therefore, the Cramér-Rao low bound (CRLB) of motion parameters can be computed easily using the waveforms of the libraries, which facilitate the subsequent waveform scheduled work. Simulation results show that the library waveforms can reduce delay resolution to satisfy the different situations and can bring significant benefits for delay resolution, orthogonality and reuse interval.

Estilos ABNT, Harvard, Vancouver, APA, etc.

3

Liu, Tianqu, Jinping Sun, Guohua Wang, Xianxun Yao e Yaqiong Qiao. "Optimal Design of Group Orthogonal Phase-Coded Waveforms for MIMO Radar". Mathematics 12, n.º 6 (19 de março de 2024): 903. http://dx.doi.org/10.3390/math12060903.

Texto completo da fonte

Resumo:

Digital radio frequency memory (DRFM) has emerged as an advanced technique to achieve a range of jamming signals, due to its capability to intercept waveforms within a short time. multiple-input multiple-output (MIMO) radars can transmit agile orthogonal waveform sets for different pulses to combat DRFM-based jamming, where any two groups of waveform sets are also orthogonal. In this article, a group orthogonal waveform optimal design model is formulated in order to combat DRFM-based jamming by flexibly designing waveforms for MIMO radars. Aiming at balancing the intra- and intergroup orthogonal performances, the objective function is defined as the weighted sum of the intra- and intergroup orthogonal performance metrics. To solve the formulated model, in this article, a group orthogonal waveform design algorithm is proposed. Based on a primal-dual-type method and proper relaxations, the proposed algorithm transforms the original problem into a series of simple subproblems. Numerical results demonstrate that the obtained group orthogonal waveforms have the ability to flexibly suppress DRFM-based deceptive jamming, which is not achievable using p-majorization–minimization (p-MM) and primal-dual, two of the most advanced orthogonal waveform design algorithms.

Estilos ABNT, Harvard, Vancouver, APA, etc.

4

Hong, Sheng, Yantao Dong, Rui Xie, Yu Ai e Yuhao Wang. "Constrained Transmit Beampattern Design Using a Correlated LFM-PC Waveform Set in MIMO Radar". Sensors 20, n.º 3 (31 de janeiro de 2020): 773. http://dx.doi.org/10.3390/s20030773.

Texto completo da fonte

Resumo:

This paper considers the design of a desired transmit beampattern under the good ambiguity function constraint using a correlated linear frequency modulation-phase coded (LFM-PC) waveform set in multiple-input-multiple-output (MIMO) radar. Different from most existing beampattern design approaches, we propose using the LFM-PC waveform set to conquer the challenging problem of synthesizing waveforms with constant-envelope and easy-generation properties, and, meanwhile, solve the hard constraint of a good ambiguity behaviour. First, the ambiguity function of the LFM-PC waveform set is derived, and the superiority of LFM-PC waveforms over LFM and PC waveforms is verified. The temporal and spatial characteristic analysis of the LFM-PC waveform set demonstrates that both the transmit beampattern and sidelobe level are mainly affected by the frequency intervals, bandwidths, and phase-coded sequences of the LFM-PC waveform set. Finally, the constrained beampattern design problem is formulated by optimizing these parameters for desired beampatterns and low sidelobes at different doppler frequencies, which is a bi-objective optimization problem. To solve this, we propose a joint optimization strategy followed by a mandatory optimization, where the sequence quadratic programming (SQP) algorithm and adaptive clonal selection (ACS) algorithm are exploited iteratively. The simulation results demonstrate the efficiency of our proposed method.

Estilos ABNT, Harvard, Vancouver, APA, etc.

5

Lei, Wei, Yue Zhang, Zengping Chen, Xiaolong Chen e Qiang Song. "Spatial–Temporal Joint Design and Optimization of Phase-Coded Waveform for MIMO Radar". Remote Sensing 16, n.º 14 (19 de julho de 2024): 2647. http://dx.doi.org/10.3390/rs16142647.

Texto completo da fonte

Resumo:

By simultaneously transmitting multiple different waveform signals, a multiple-input multiple-output (MIMO) radar possesses higher degrees of freedom and potential in many aspects compared to a traditional phased-array radar. The spatial–temporal characteristics of waveforms are the key to determining their performance. In this paper, a transmitting waveform design method based on spatial–temporal joint (STJ) optimization for a MIMO radar is proposed, where waveforms are designed not only for beam-pattern matching (BPM) but also for minimizing the autocorrelation sidelobes (ACSLs) of the spatial synthesis signals (SSSs) in the directions of interest. Firstly, the STJ model is established, where the two-step strategy and least squares method are utilized for BPM, and the L2p-Norm of the ACSL is constructed as the criterion for temporal characteristics optimization. Secondly, by transforming it into an unconstrained optimization problem about the waveform phase and using the gradient descent (GD) algorithm, the hard, non-convex, high-dimensional, nonlinear optimization problem is solved efficiently. Finally, the method’s effectiveness is verified through numerical simulation. The results show that our method is suitable for both orthogonal and partial-correlation MIMO waveform designs and efficiently achieves better spatial–temporal characteristic performances simultaneously in comparison with existing methods.

Estilos ABNT, Harvard, Vancouver, APA, etc.

6

Chang, Shaoqiang, Fawei Yang, Zhennan Liang, Wei Ren, Hao Zhang e Quanhua Liu. "Slow-Time MIMO Waveform Design Using Pulse-Agile-Phase-Coding for Range Ambiguity Mitigation". Remote Sensing 15, n.º 13 (4 de julho de 2023): 3395. http://dx.doi.org/10.3390/rs15133395.

Texto completo da fonte

Resumo:

This paper proposed a Pulse-Agile-Phase-Coding slow-time MIMO (PAPC-st-MIMO) waveform, where the phase-coded signal is utilized as the intra-pulse modulation of the slow-time MIMO waveform. Firstly, the signal model of the proposed waveform is derived. To improve the orthogonality of the phase-coded waveform sets, a novel hybrid evolutionary algorithm based on Cyclic Algorithm New (CAN) is proposed. After the optimization process of the phase-coded waveform sets, the signal processing method of the PAPC-st-MIMO waveform is derived. Finally, the effectiveness of the proposed method is verified with a simulation experiment. The mitigation ratio of the near-range detection waveform can achieve −30 dB, while the long-range detection waveform can achieve −35 dB. This approach ensures waveform orthogonality while enabling the slow-time MIMO waveform to achieve distance selectivity. By conducting joint pulse-Doppler processing across multiple range segments, range ambiguity can be suppressed, increasing the system’s Pulse Repetition Frequency (PRF) without introducing ambiguity.

Estilos ABNT, Harvard, Vancouver, APA, etc.

7

Meng, Huadong, Yimin Wei, Xuhua Gong, Yimin Liu e Xiqin Wang. "Radar Waveform Design for Extended Target Recognition under Detection Constraints". Mathematical Problems in Engineering 2012 (2012): 1–15. http://dx.doi.org/10.1155/2012/289819.

Texto completo da fonte

Resumo:

We address the problem of radar phase-coded waveform design for extended target recognition in the presence of colored Gaussian disturbance. Phase-coded waveforms are selected since they can fully exploit the transmit power with sufficient variability. An important constraint, target detection performance, is considered to meet the practical requirements. The waveform is designed to achieve maximum recognition performance under a control on the achievable signal-to-noise ratio (SNR) of every possible target hypothesis. We formulate the code design in terms of a nonconvex, NP-hard quadratic optimization problem in the cases of both continuous and discrete phases. Techniques based on semidefinite relaxation (SDR) and randomization are proposed to approximate the optimal solutions. Simulation results show that the recognition performance and the detection requirements are well balanced and accurate approximations are achieved.

Estilos ABNT, Harvard, Vancouver, APA, etc.

8

Vierinen, Juha, Jorge L. Chau, Nico Pfeffer, Matthias Clahsen e Gunter Stober. "Coded continuous wave meteor radar". Atmospheric Measurement Techniques 9, n.º 2 (3 de março de 2016): 829–39. http://dx.doi.org/10.5194/amt-9-829-2016.

Texto completo da fonte

Resumo:

Abstract. The concept of a coded continuous wave specular meteor radar (SMR) is described. The radar uses a continuously transmitted pseudorandom phase-modulated waveform, which has several advantages compared to conventional pulsed SMRs. The coding avoids range and Doppler aliasing, which are in some cases problematic with pulsed radars. Continuous transmissions maximize pulse compression gain, allowing operation at lower peak power than a pulsed system. With continuous coding, the temporal and spectral resolution are not dependent on the transmit waveform and they can be fairly flexibly changed after performing a measurement. The low signal-to-noise ratio before pulse compression, combined with independent pseudorandom transmit waveforms, allows multiple geographically separated transmitters to be used in the same frequency band simultaneously without significantly interfering with each other. Because the same frequency band can be used by multiple transmitters, the same interferometric receiver antennas can be used to receive multiple transmitters at the same time. The principles of the signal processing are discussed, in addition to discussion of several practical ways to increase computation speed, and how to optimally detect meteor echoes. Measurements from a campaign performed with a coded continuous wave SMR are shown and compared with two standard pulsed SMR measurements. The type of meteor radar described in this paper would be suited for use in a large-scale multi-static network of meteor radar transmitters and receivers. Such a system would be useful for increasing the number of meteor detections to obtain improved meteor radar data products.

Estilos ABNT, Harvard, Vancouver, APA, etc.

9

Kim, Dong-Hoon, Hyung-Jung Kim e Jae-Han Lim. "Design of Optimized Coded LFM Waveform for Spectrum Shared Radar System". Sensors 21, n.º 17 (28 de agosto de 2021): 5796. http://dx.doi.org/10.3390/s21175796.

Texto completo da fonte

Resumo:

To meet the increasing demands for remote sensing, a number of radar systems using Linear Frequency Modulation (LFM) waveforms have been deployed, causing the problem of depleting frequency resources. To address this problem, several researchers have proposed the Spectrum Shared Radar System (SSRS) in which multiple radars share the same frequency band to transmit and receive their own signals. To mitigate the interferences caused by the signal transmission by other radars, SSRS employs orthogonal waveforms that inherit the orthogonality of the waveforms from orthogonal codes. However, the inherited orthogonality of the codes is significantly reduced when incorporating LFM waveforms with the codes. To solve this problem, in this paper, we propose a novel but simple scheme for generating a set of optimized coded LFM waveforms via new optimization framework. In the optimization framework, we minimize the weighted sum of autocorrelation sidelobe peaks (ASP) and cross-correlation peaks (CP) of the coded LFM waveforms to maximize the orthogonality of the waveforms. Through computer simulations, we show that the waveforms generated by the proposed scheme outperform the waveforms created by previous proposals in terms of ASP and CP.

Estilos ABNT, Harvard, Vancouver, APA, etc.

10

Zhang, J. D., X. H. Zhu e H. Q. Wang. "Adaptive radar phase-coded waveform design". Electronics Letters 45, n.º 20 (2009): 1052. http://dx.doi.org/10.1049/el.2009.1099.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

11

Yan, Huabin, Shiyuan Zhang, Xingyu Lu, Jianchao Yang, Lunhao Duan, Ke Tan e Hong Gu. "A Waveform Design for Integrated Radar and Jamming Based on Smart Modulation and Complementary Coding". Remote Sensing 16, n.º 15 (25 de julho de 2024): 2725. http://dx.doi.org/10.3390/rs16152725.

Texto completo da fonte

Resumo:

Waveform design for integrated radar and jamming is generally based on the concept of shared waveform, which uses jamming signals without typical radar signal characteristics for detection. Existing waveforms have shown limited design flexibility, high levels of sidelobe in detection results, and overall ordinary performance. We propose an integrated radar and jamming waveform based on smart modulation and complementary coding. Unlike traditional integrated radar and jamming waveform based on smart modulation, the phase angle of the binary phase-coded sequence is adjustable in this smart modulation method, allowing for a controllable jamming effect, achieving true smart modulation. However, this smart modulation waveform also suffers from high sidelobes in detection. To address this issue, we take a complementary coding approach and design a smart modulation waveform with complementary characteristics. This waveform can synthesize a complete linear frequency modulation (LFM) signal by adding two pulses together, thereby reducing the sidelobes in the smart modulation waveform and enhancing its detection performance. Theoretical analysis indicates that the detection and jamming effects of this integrated waveform can be flexibly controlled by adjusting the phase angles of the coding sequences. Simulation analysis and experimental results confirm the significant advantages of this waveform.

Estilos ABNT, Harvard, Vancouver, APA, etc.

12

Duan, Tong, Hong Liang, Zezhou Dai e Lei Yue. "High-Resolution Wideband Waveform Design for Sonar Based on Multi-Parameter Modulation". Remote Sensing 15, n.º 18 (19 de setembro de 2023): 4603. http://dx.doi.org/10.3390/rs15184603.

Texto completo da fonte

Resumo:

The design of transmitting waveforms is an effective way to improve the detection performance of sonar systems. For the problem of high-range sidelobe when designing reverberation-resistant waveforms, this paper proposes a high-resolution wideband composite waveform design with reverberation suppression performance and a waveform parameter improvement method. Firstly, we propose a novel wideband waveform, which utilizes linear frequency modulation (LFM) as the fundamental pulse, referred to as multi-parameter coded modulation LFM pulse (MPCM-LFM). Additionally, we deduce the wideband ambiguity function for waveform design. Then, we deduce the constraint relations of the waveform parameters for different sub-band overlaps, and according to the mathematical expressions of the obtained range ambiguity function, we analyze in detail the effects of the waveform parameters on the range ambiguity function under different constraints. Secondly, on the basis of the analysis, we also propose a hopping carrier frequency constraint rule to optimize the spectral performance, and the range sidelobe is restrained effectively in significant measure by this parameter improvement method. Finally, we analyze the computer simulation results. It is obvious that our proposed waveform parameter improvement method leads to good results. The proposed improved MPCM-LFM signal shows a “near-thumbtack” ambiguity function, whose sidelobe suppression performance is superior to other classical waveforms in the desired region, and it can realize high-precision parameter estimation. In addition, the proposed improved MPCM-LFM signal possesses good performance in detecting stationary and low Doppler targets in the background of reverberation.

Estilos ABNT, Harvard, Vancouver, APA, etc.

13

Kumari Chilukuri, Raja, Hari Kishore Kakarla e K. Subba Rao. "Radar Signal Recognition Based on Multilayer Perceptron Neural Network". International journal of electrical and computer engineering systems 14, n.º 1 (26 de janeiro de 2023): 29–36. http://dx.doi.org/10.32985/ijeces.14.1.4.

Texto completo da fonte

Resumo:

Low Probability of Intercept (LPI) radars are developed on an advanced architecture by making use of coded waveforms. Detection and classification of radar waveforms are important in many critical applications like electronic warfare, threat to radar and surveillance. Precise estimation of parameter and classification of the type of waveform will provide information about the threat to the radar and also helps to develop sophisticated intercept receiver. The present work is on classification of modulation waveforms of LPI radar using multilayer perceptron neural (MLPN) network. The classification approach is based on the following two steps. In the first step, the waveforms are analysed using cyclstationary technique which models the signal in bi-frequency (BF) plane. Using this algorithm, the BF images of the signals are obtained. In the second step, the BF images are fed to a feature extraction unit to get the salient features of the waveform and then to the multilayer perceptron neural (MLPN) network for classification. Nine types of noise free modulation waveforms (Frank, four polyphase codes and four poly time codes) are classified using the images obtained in the first step. The success rate achieved is 100 % for noise free signals. The experiment is repeated for various noise levels up to -12dB SNR. The noisy signals, before feeding to the MLPN network, are denoised using two types of denoising filters connected in cascade and the classification success rate achieved is 93.3% for signals up to -12dB SNR.

Estilos ABNT, Harvard, Vancouver, APA, etc.

14

Cai, Long, Xiao Chuan Ma, She Feng Yan e Qi Xu. "On Orthogonal Waveform Design for MIMO Radar". Advanced Materials Research 181-182 (janeiro de 2011): 422–28. http://dx.doi.org/10.4028/www.scientific.net/amr.181-182.422.

Texto completo da fonte

Resumo:

MIMO radar system that transmits orthogonal waveforms is an emerging technology that has significant application potential. Compared to traditional phased-array radar, orthogonal transform waveform can bring many advantages. In this paper, we present a novel binary phase code sequence suitable for orthogonal design. This phase code sequence is computationally efficient compared to other algorithms previously proposed in the literature. We provide some numerical examples to demonstrate the performances of the coded pulse signal.

Estilos ABNT, Harvard, Vancouver, APA, etc.

15

Chandrasekar, V., e Nitin Bharadwaj. "Orthogonal Channel Coding for Simultaneous Co- and Cross-Polarization Measurements". Journal of Atmospheric and Oceanic Technology 26, n.º 1 (1 de janeiro de 2009): 45–56. http://dx.doi.org/10.1175/2008jtecha1101.1.

Texto completo da fonte

Resumo:

Abstract Dual-polarization weather radars typically measure the radar reflectivity at more than one polarization state for transmission and reception. Historically, dual-polarization radars have been operated at copolar and cross-polar states defined with respect to the transmit polarization states. Recently, based on the improved understanding of the propagation properties of electromagnetic waves in precipitation media, the simultaneous transmit and receive (STAR) mode has become common to simplify the hardware. In the STAR mode of operation, horizontal and vertical polarization states are transmitted simultaneously and samples of both horizontal and vertical copolar returns are obtained. A drawback of the current implementation of STAR mode is its inability to measure parameters obtained from cross-polar signals such as linear depolarization ratio (LDR). In this paper, a technique to obtain cross-polar signals with STAR mode waveform is presented. In this technique, the horizontally and vertically polarized transmit waveforms are coded with orthogonal phase sequences. The performance of the phase-coded waveform is determined by the properties of the phase codes. This orthogonal phase coding technique is implemented in the Colorado State University–University of Chicago–Illinois State Water Survey (CSU–CHILL) radar. This paper outlines the methodology and presents the performance of the cross-polar and copolar parameter estimation based on the simulation as well as data collected from the CSU–CHILL radar.

Estilos ABNT, Harvard, Vancouver, APA, etc.

16

Kamble, Jayshree, I. A Pasha e M. Madhavilatha. "Poly-phase signal generation and optimizationof LPI Radar: A new approach". International Journal of Engineering & Technology 7, n.º 2.6 (11 de março de 2018): 147. http://dx.doi.org/10.14419/ijet.v7i2.6.10141.

Texto completo da fonte

Resumo:

Low Probability of Intercept (LPI) Radar own certain positive characteristics make them nearly undetectable by Intercept Receivers. In a battle field, this present a considerable strategic problem. New digital receivers required complex signal processing techniques to detect these types of Radar. This paper address the problem of constructing a new hybrid waveform design using Poly-Phase modulation technique to optimize the detection performance of LPI Radar. Phase coded Pulse compression waveforms using Frequency Hopping Spread Spectrum (FHSS) are designed to evaluate the detection performance of LPI radar in terms of Discrimination factor (DF).The difference in DF of the Poly-phase coded and Binary phase coded signals is increasing with the increase in the phase values.The effect of noise on Hybrid Poly-Phase waveforms examined using the signal to noise ratios of -10dB,-15dB and -20dB and extract the parameter necessary for the LPI Radar system.

Estilos ABNT, Harvard, Vancouver, APA, etc.

17

Xi, Rongyan, Dingyou Ma, Xiang Liu, Lei Wang e Yimin Liu. "Intra-Pulse Frequency Coding Design for a High-Resolution Radar against Smart Noise Jamming". Remote Sensing 14, n.º 20 (14 de outubro de 2022): 5149. http://dx.doi.org/10.3390/rs14205149.

Texto completo da fonte

Resumo:

Smart noise jamming forms active jamming by intercepting, modulating, and forwarding radar signals into the radar receiver, which seriously affects the radar range recovery performance. In this paper, we propose a novel waveform design approach and an efficient range recovery method for high-resolution radar in the jamming scenario. Firstly, we propose an intra-pulse frequency-coded frequency-modulated continuous waveform (IPFC-FMCW), which contains multiple FMCW chips with different widths and frequencies, to combat the smart noise jamming. After the jamming suppression, the proposed waveform has a low sidelobe level, which is different from traditional FMCW signals for which the observations are periodically missing, resulting in high sidelobe levels. Then, to improve the range recovery performance of the waveform after jamming suppression, we optimize the range profile by designing the transmit waveform and then solve it by a simulated annealing algorithm. Next, based on the designed waveform, we derive the echo model after jamming suppression and propose a gridless compressed sensing (CS) method to recover the range of the targets. Compared with the existing waveforms and methods, the proposed waveform and the processing method achieve better range recovery performance in the jamming scenario. Numerical simulations are utilized to demonstrate the range recovery effectiveness of the proposed waveform and method in smart noise jamming.

Estilos ABNT, Harvard, Vancouver, APA, etc.

18

Walenczykowska, Marta, e Adam Kawalec. "Application of Continuous Wavelet Transform and Artificial Naural Network for Automatic Radar Signal Recognition". Sensors 22, n.º 19 (30 de setembro de 2022): 7434. http://dx.doi.org/10.3390/s22197434.

Texto completo da fonte

Resumo:

This article aims to propose an algorithm for the automatic recognition of selected radar signals. The algorithm can find application in areas such as Electronic Warfare (EW), where automatic recognition of the type of intra-pulse modulation or the type of emitter operation mode can aid the decision-making process. The simulations carried out included the analysis of the classification possibilities of linear frequency modulated pulsed waveform (LFMPW), stepped frequency modulated pulsed waveform (SFMPW), phase coded pulsed waveform (PCPW), rectangular pulsed waveforms (RPW), frequency modulated continuous wave (FMCW), continuous wave (CW), Stepped Frequency Continuous Wave SFCW) and Phase Coded Continuous Waveform (PCCW). The algorithm proposed in this paper is based on the use of continuous wavelet transform (CWT) coefficients and higher-order statistics (HOS) in the feature determination of selected signals. The Principal Component Analysis (PCA) method was used for dimensionality reduction. An artificial neural network was then used as a classifier. Simulation studies took into account the presence of noise interference with signal-to-noise ratio (SNR) in the range from −5 to 10 dB. Finally, the obtained classification efficiency is presented in the form of a confusion matrix. The simulation results show a high recognition test accuracy, above 99% with a signal-to-noise ratio greater than 0 dB. The article also deals with the selection of the type and parameters of the wavelet. The authors also point to the problems encountered during the research and examples of how to solve them.

Estilos ABNT, Harvard, Vancouver, APA, etc.

19

Hornbostel, Scott C., e A. H. Thompson. "Waveform design for electroseismic exploration". GEOPHYSICS 72, n.º 2 (março de 2007): Q1—Q10. http://dx.doi.org/10.1190/1.2436473.

Texto completo da fonte

Resumo:

In earlier work, we described field tests that successfully detected electromagnetic-to-seismic (ES) conversions from gas sands and carbonate reservoirs. ES conversion amplitudes measure the electric properties of permeable rock with near-seismic resolution. This information is a new indicator of hydrocarbons. ES conversions produce small seismic responses. Detecting these signals requires high-power electromagnetic sources and high-sensitivity detectors. Extraction of signal from noise also requires sophisticated signal processing. Here, we describe coded waveforms of binary sequences optimized for the expected signals. These coded waveforms distinguish between linear and nonlinear conversions. We detected both linear and nonlinear conversions in field studies. Novel, high-power signal generators synthesize the required sequences from three-phase power lines. The electroseismic exploration system includes optimized source electrodes and digital accelerometers that are free of electromagnetic interference.

Estilos ABNT, Harvard, Vancouver, APA, etc.

20

Tian, Xuanxuan, Tingting Zhang, Qinyu Zhang e Zhaohui Song. "HRR Profiling on Integrated Radar-Communication Systems Using OFDM-PCSF Signals". Mathematical Problems in Engineering 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/5357187.

Texto completo da fonte

Resumo:

In order to improve both the transmission data rate and the range resolution simultaneously in integrated radar-communication (RadCom) systems, orthogonal frequency-division multiplexing with phase-coded and stepped-frequency (OFDM-PCSF) waveform is proposed. A corresponding high resolution range (HRR) profile generation method is also presented. We first perform OFDM-PCSF waveform design by combining the intrapulse phase coding with the interpulse stepped-frequency modulation. We then give the ambiguity function (AF) based on the presented waveforms. Then, the synthetic range profile (SRP) processing to achieve HRR performance is analyzed. Theoretical analysis and simulation results show that the proposed methods can achieve HRR profiles of the targets and high data rate transmissions, while a relative low computational complexity can be achieved.

Estilos ABNT, Harvard, Vancouver, APA, etc.

21

Gao, Hao, e Xu Dong Zhang. "Automatic Radar Waveform Recognition Using SVM". Applied Mechanics and Materials 229-231 (novembro de 2012): 2348–51. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.2348.

Texto completo da fonte

Resumo:

In this paper, a new feature for radar waveform recognition based on the instantaneous frequency is proposed. It is especially utilized for discriminating phase coded signals from other signals. Maximum likelihood estimation (MLE), autocorrelation algorithm, and likelihood ratio test are exploited in the algorithm. In the classification system, support vector machine (SVM) offers an efficient approach to classify linear frequency modulation (LFM) signals, phase coded signals and single frequency signals. Simulation results indicate that the new feature vectors perform effectively over a large range of SNRs. Furthermore, the new classifier achieves a very robust performance that the correct rate is over 90% at SNR of 5 dB, and the ever-increasing rate has been over 97% since SNR of 10dB.

Estilos ABNT, Harvard, Vancouver, APA, etc.

22

Cheng, Sheng-Juan, Wen-Qin Wang e Huai-Zong Shao. "Spread Spectrum-Coded OFDM Chirp Waveform Diversity Design". IEEE Sensors Journal 15, n.º 10 (outubro de 2015): 5694–700. http://dx.doi.org/10.1109/jsen.2015.2448617.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

23

Xu, Lei, Qilian Liang, Xiaorong Wu e Baoju Zhang. "Phase Coded Waveform Design for Sonar Sensor Network". Mobile Networks and Applications 18, n.º 2 (24 de fevereiro de 2012): 215–21. http://dx.doi.org/10.1007/s11036-012-0352-8.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

24

Wang, Charles C., e Dean J. Sklar. "Metric transformation for a turbo-coded DPSK waveform". Wireless Communications and Mobile Computing 3, n.º 5 (2003): 609–16. http://dx.doi.org/10.1002/wcm.144.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

25

Liu, Tianqu, Jinping Sun, Guohua Wang e Yilong Lu. "A Multi-Objective Quantum Genetic Algorithm for MIMO Radar Waveform Design". Remote Sensing 14, n.º 10 (16 de maio de 2022): 2387. http://dx.doi.org/10.3390/rs14102387.

Texto completo da fonte

Resumo:

Aiming at maximizing waveform diversity gain when designing a phase-coded multiple-input multiple-output (MIMO) radar waveform set, it is desirable that all waveforms are orthogonal to each other. Hence, the lowest possible peak cross-correlation ratio (PCCR) is expected. Meanwhile, low peak auto-correlation side-lobe ratio (PASR) is needed for good detection performance. However, it is difficult to obtain a closed form solution to the waveform set from the expected values of the PASR and PCCR. In this paper, the waveform set design problem is modeled as a multi-objective, NP-hard constrained optimization problem. Unlike conventional approaches that design the waveform set through optimizing a weighted sum objective function, the proposed optimization model evaluates the performance of multi-objective functions based on Pareto level and obtains a set of Pareto non-dominated solutions. That means that the MIMO radar system can trade off each objective function for different requirements. To solve this problem, this paper presents a multi-objective quantum genetic algorithm (MoQGA) based on the framework of quantum genetic algorithm. A new population update strategy for the MoQGA is designed based on the proposed model. Compared to the state-of-the-art methods, like BiST and Multi-CAN, the PASR and PCCR metrics of the waveform set are 0.95–3.91 dB lower with the parameters of the numerical simulation. The MoQGA is able to minimize PASR and PCCR of the MIMO radar waveform set simultaneously.

Estilos ABNT, Harvard, Vancouver, APA, etc.

26

Priya, Bhanu, e Jyoteesh Malhotra. "Error Rate Performance of Potential Multicarrier Waveforms and Coding Techniques for 5G". International Journal of Sensors, Wireless Communications and Control 10, n.º 2 (15 de setembro de 2020): 231–47. http://dx.doi.org/10.2174/2210327909666190409130000.

Texto completo da fonte

Resumo:

Background: The wisdom of future wireless communication is clearly highlighted by the gigabit experience, low latency and the three fold rises in the capacity, compared to the 4th Generation networks. To meet such an ambitious objective of the 5th Generation communication systems, efficient use of non-contiguous unused spectrum is required. The panacea to this issue lies in the symbiosis of multicarrier waveforms and coding schemes. Methods: To study the interaction between these two, several multicarrier waveforms like Filtered- OFDM (F-OFDM), Universal Filtered Multi-Carrier (UFMC) and Weighted Overlap and Add (WOLA) which act as a powerful contender to win the 5G candidate waveform race, are analyzed in Low-Density Parity Check Codes (LDPC), Polar and Turbo coded representative Third Generation Partnership Project (3GPP) channel models under a common numerology framework. This article dwells upon the error rate and throughput performance of different modulation formats and coding schemes appropriate for the 5G in a well-defined multi-cellular environment. Results and Conclusion: The results have shown that even though many waveforms and coding techniques may pave the route towards its adoption as a physical layer standard instead of classical OFDM and convolution codes but no one is a clear conqueror as their selection depends upon the considered environment and type of traffic.

Estilos ABNT, Harvard, Vancouver, APA, etc.

27

Wang, Xiaoge, Binbin Li, Hui Chen, Weijian Liu, Yongzhe Zhu, Jun Luo e Liuliu Ni. "Interrupted-Sampling Repeater Jamming Countermeasure Based on Intrapulse Frequency–Coded Joint Frequency Modulation Slope Agile Waveform". Remote Sensing 16, n.º 15 (31 de julho de 2024): 2810. http://dx.doi.org/10.3390/rs16152810.

Texto completo da fonte

Resumo:

Interrupted-sampling repeater jamming (ISRJ) is widely used in the field of electronic countermeasures, and can severely affect radar detection. Therefore, the problem of ISRJ suppression is a compelling task. In this paper, we propose an ISRJ suppression method based on an intrapulse frequency-coded joint frequency modulation (FM) slope agile waveform. The intrapulse frequency-coded joint FM slope agile waveform is first designed. The delay inserted between subpulses makes the waveform easy to implement in engineering, and the ambiguity function diagram of the waveform approximates the ideal thumbtack type. Next, the echo slices are classified in the fractional domain utilizing the discontinuity of ISRJ and the focusing property of fractional Fourier transform for chirp signals. Then, the target and interference in the interfered echo slices are reconstructed by compressed sensing, and a time-domain filter is constructed based on interference-free echo slices. Finally, the echo signal after interference suppression is further filtered in the time domain to degrade range sidelobes. Simulation results show that the proposed method can effectively suppress three typical types of ISRJ. Moreover, the probability of target detection after interference suppression exceeds 90% when the jamming-to-signal ratio equals 50 dB.

Estilos ABNT, Harvard, Vancouver, APA, etc.

28

Luo, Zhi-Tao, Peng Shen, Hao Luo, Sheng Wang, Xin-Kai Wu e Hui Zhang. "Advanced orthogonal frequency and phase modulated waveform for contrast-enhanced photothermal wave radar thermography". Journal of Applied Physics 131, n.º 22 (14 de junho de 2022): 224903. http://dx.doi.org/10.1063/5.0087734.

Texto completo da fonte

Resumo:

Thermal wave radar (TWR) thermography is a high-efficient nondestructive testing technique to increase the signal-to-noise ratio (SNR) and to enhance target detection capability. However, the detection of subsurface defects, especially small-size defects, usually requires a distinctively high SNR and depth resolvability. This paper proposed an orthogonal phase-coded linear frequency modulated (OPCLFM) excitation waveform, which has significantly improved the SNR and depth resolvability of TWR compared to the LFM waveform. The pulse compression quality of the OPCLFM waveform was initially evaluated through a 1D thermal wave analytical model of carbon fiber reinforced polymer (CFRP) laminate. Results show that the OPCLFM waveform combined with the Kaiser window function compresses the largest sidelobe at least by 18.39 dB compared to the LFM waveform. Furthermore, the superior depth resolvability performance of the OPCLFM waveform was also validated by 3D finite element simulation. Finally, the effect of thermal conductivity on the depth resolvability performance of the OPCLFM waveform was evaluated quantitatively by a delaminated CFRP laminate.

Estilos ABNT, Harvard, Vancouver, APA, etc.

29

Yang, Wei Dong, Li Li e Kai Peng. "Realization of Low Frequency Wakeup in Tire Encoded Radio Frequency Identification System". Applied Mechanics and Materials 556-562 (maio de 2014): 2895–98. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.2895.

Texto completo da fonte

Resumo:

In car tires coded identification system, radio frequency technology plays a vital role, the key to radio frequency signals transmitted process is waveform modulation. The key of adjusting the waveform is how to match its resistor and capacitor easily. In the paper their resistance and capacitance values are optimized by using the simulation software (Protues) to simulate the transmitted waveform, and based on matching results the optimized physical models are produced. The actual test results agree well with the simulation results. The method of simulation tests can save the resources effectively, and shorten the development time.

Estilos ABNT, Harvard, Vancouver, APA, etc.

30

Zhu, Sha, Kunpeng Zhai, Wei Li e Ning Hua Zhu. "Stimulated-Brillouin-scattering-based arbitrarily phase coded microwave waveform transmitter with anti-dispersion transmission". Chinese Optics Letters 20, n.º 8 (2022): 083901. http://dx.doi.org/10.3788/col202220.083901.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

31

Yucel, Mehmet K., Sina Fateri, Mathew Legg, Adam Wilkinson, Vassilios Kappatos, Cem Selcuk e Tat-Hean Gan. "Coded Waveform Excitation for High-Resolution Ultrasonic Guided Wave Response". IEEE Transactions on Industrial Informatics 12, n.º 1 (fevereiro de 2016): 257–66. http://dx.doi.org/10.1109/tii.2015.2501762.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

32

Moharir, P. S., V. M. Maru e R. Singh. "Bi-parental product algorithm for coded waveform design in radar". Sadhana 22, n.º 5 (outubro de 1997): 589–99. http://dx.doi.org/10.1007/bf02802547.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

33

Shang, Pingping, Hyein Lee e Sooyoung Kim. "Waveform Design for Space–Time Coded MIMO Systems with High Secrecy Protection". Electronics 9, n.º 12 (25 de novembro de 2020): 2003. http://dx.doi.org/10.3390/electronics9122003.

Texto completo da fonte

Resumo:

In this paper, we present a new secrecy-enhancing scheme for multi-input-multi-output (MIMO) systems using a space–time coding scheme. We adopt a quasi-orthogonal space–time block coding (QO-STBC) scheme that was originally designed to improve the performance of the MIMO system, and propose an efficient waveform design that can enhance the secrecy, as well as improve the error rate performance. Channel- and signal-dependent artificial interference (AI) is added to the proposed waveform, so that only a legitimate receiver can successfully retrieve information. We investigate the secrecy capacity of the proposed scheme, and demonstrate that the proposed scheme provides highly enhanced secrecy performance, compared to the conventional schemes. The performance simulation results reveal that the transmitted information can be properly extracted only at the legitimate receiver.

Estilos ABNT, Harvard, Vancouver, APA, etc.

34

Xie, Ya Nan, e Jia Jia Wang. "Orthogonal Discrete Frequency-Phase Waveform Design Based on Hybrid Chaos for MIMO Radar". Advanced Materials Research 989-994 (julho de 2014): 3621–24. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.3621.

Texto completo da fonte

Resumo:

Based on the good correlation and randomness of chaos, this paper uses hybrid Bernouli and Logistic chaotic maps to increase the complexity of chaos, at the same time, we do a combination of discrete frequency coded of non full code sets and poly phase coded, and then hybrid modulation waveforms base on hybrid chaos is proposed for MIMO radar. On the basis of the expression of average ambiguity function is derived, the average fuzzy characteristics of signal waveforms and orthogonality are analyzed in theory. Finally, numerical simulation results validate the correctness of the analysis and the reliability of the signal model.

Estilos ABNT, Harvard, Vancouver, APA, etc.

35

Guan, Jian, Xiaoqian Mu, Yong Huang, Baoxin Chen, Ningbo Liu e Xiaolong Chen. "A Space–Time–Range Joint Adaptive Focusing and Detection Method for Multiple Input Multiple Output Radar". Remote Sensing 15, n.º 18 (13 de setembro de 2023): 4509. http://dx.doi.org/10.3390/rs15184509.

Texto completo da fonte

Resumo:

The Multiple Input Multiple Output (MIMO) radar, as a new type of radar, emits orthogonal waveforms, which provide it with waveform diversity characteristics, leading to increased degrees of freedom and improved target detection performance. However, it also poses challenges such as difficulty in meeting higher data demand, separating waveforms, and suppressing the multidimensional sidelobes (range sidelobes, Doppler sidelobes, and angle sidelobes) of targets. Phase-coded signals are frequently employed as orthogonal transmission signals in the MIMO radar. However, these signals exhibit poor Doppler sensitivity, and the intra-pulse Doppler frequency shift can have an impact on the effectiveness of the matching filtering process. To address the aforementioned concerns, this paper presents a novel approach called the Space–Time–Range Joint Adaptive Focusing and Detection (STRJAFD) method. The proposed method utilizes the Mean Square Error (MSE) criterion and integrates spatial, temporal, and waveform dimensions to achieve efficient adaptive focusing and detection of targets. The experimental results demonstrate that the proposed method outperforms conventional cascaded adaptive methods in effectively addressing the matching mismatch issue caused by Doppler frequency shift, achieving super-resolution focusing, possessing better suppression effects on three-dimensional sidelobes and clutter, and exhibiting better detection performance in low signal-to-clutter ratio and low signal-to-noise ratio environments. Furthermore, STRJAFD is unaffected by coherent sources and demands less data.

Estilos ABNT, Harvard, Vancouver, APA, etc.

36

Takayama, Takuya, Masayuki Sugano, Yukinobu Tokieda e Hiroki Sugawara. "Hybrid SIMO and MIMO sparse array radar". International Journal of Microwave and Wireless Technologies 6, n.º 3-4 (15 de abril de 2014): 389–95. http://dx.doi.org/10.1017/s1759078714000154.

Texto completo da fonte

Resumo:

This paper clarifies what we benefit from single-input–multiple-output (SIMO) or multiple-input–multiple-output (MIMO) radar. We have developed an X-band sparse array imaging radar system capable of operating at both SIMO and MIMO modes. The hybrid radar modes are realized without any modification in hardware, but simply by switching the scheme of waveform generation and post-processing. A comparison has been made between the SIMO mode adopting a chirp pulse waveform and the MIMO mode based on the code-division multiple access method using the Gold-coded pulse waveform. Mutually complementary properties between the SIMO and MIMO modes in terms of the cost of computation, the ease of array calibration, and the detectability of targets are clarified through simulations and an experiment.

Estilos ABNT, Harvard, Vancouver, APA, etc.

37

Song, Chunqi, Shanguo Huang, Xinlu Gao, Zhennan Zheng, Xiyao Song, Yunping Bai, Guanjun Gao e Jingcan Ma. "Photonics Generation of Baseband-Free Arbitrary-Phase-Coded Microwave Waveform Pulse". IEEE Photonics Technology Letters 33, n.º 9 (1 de maio de 2021): 457–60. http://dx.doi.org/10.1109/lpt.2021.3068384.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

38

Zeng, Xiang-neng, Yong-shun Zhang, Bo Tian, Guo-qing Zhao e Teng Lei. "Discrete Frequency Code Waveform Based on MicPSO Cooperated with Grefenstette Coded". Journal of Electronics & Information Technology 33, n.º 1 (1 de março de 2011): 100–105. http://dx.doi.org/10.3724/sp.j.1146.2010.00244.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

39

Nakanishi, Masaki, Yutaro Tanji e Toshihisa Tanaka. "Waveform-Coded Steady-State Visual Evoked Potentials for Brain-Computer Interfaces". IEEE Access 9 (2021): 144768–75. http://dx.doi.org/10.1109/access.2021.3120623.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

40

Vierinen, J., J. L. Chau, N. Pfeffer, M. Clahsen e G. Stober. "Coded continuous wave meteor radar". Atmospheric Measurement Techniques Discussions 8, n.º 7 (30 de julho de 2015): 7879–907. http://dx.doi.org/10.5194/amtd-8-7879-2015.

Texto completo da fonte

Resumo:

Abstract. The concept of coded continuous wave meteor radar is introduced. The radar uses a continuously transmitted pseudo-random waveform, which has several advantages: coding avoids range aliased echoes, which are often seen with commonly used pulsed specular meteor radars (SMRs); continuous transmissions maximize pulse compression gain, allowing operation with significantly lower peak transmit power; the temporal resolution can be changed after performing a measurement, as it does not depend on pulse spacing; and the low signal to noise ratio allows multiple geographically separated transmitters to be used in the same frequency band without significantly interfering with each other. The latter allows the same receiver antennas to be used to receive multiple transmitters. The principles of the signal processing are discussed, in addition to discussion of several practical ways to increase computation speed, and how to optimally detect meteor echoes. Measurements from a campaign performed with a coded continuous wave SMR are shown and compared with two standard pulsed SMR measurements. The type of meteor radar described in this paper would be suited for use in a large scale multi-static network of meteor radar transmitters and receivers. This would, for example, provide higher spatio-temporal resolution for mesospheric wind field measurements.

Estilos ABNT, Harvard, Vancouver, APA, etc.

41

Sheng-Wen Huang e Pai-Chi Li. "Arbitrary waveform coded excitation using bipolar square wave pulsers in medical ultrasound". IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 53, n.º 1 (janeiro de 2006): 106–16. http://dx.doi.org/10.1109/tuffc.2006.1588396.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

42

Deng, Hong, Jiejun Zhang, Xiang Chen e Jianping Yao. "Photonic Generation of a Phase-Coded Chirp Microwave Waveform With Increased TBWP". IEEE Photonics Technology Letters 29, n.º 17 (1 de setembro de 2017): 1420–23. http://dx.doi.org/10.1109/lpt.2017.2717698.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

43

Lashkari, Bahman, Kaicheng Zhang, Edem Dovlo e Andreas Mandelis. "Coded excitation waveform engineering for high frame rate synthetic aperture ultrasound imaging". Ultrasonics 77 (maio de 2017): 121–32. http://dx.doi.org/10.1016/j.ultras.2017.02.007.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

44

Hassan, A., A. EL Sherif e K. El Barbary. "COMPUTER OPTIMIZATION OF PHASE CODED WAVEFORM PARAMETERS AND PROCESSOR FOR CLUTTER REJECTION". International Conference on Aerospace Sciences and Aviation Technology 2, CONFERENCE (1 de abril de 1987): 1–10. http://dx.doi.org/10.21608/asat.1987.26214.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

45

Tu, Bing, Wei Wang e Teng Xi Zhan. "Research on Manchester Coded Mud Pulse Signal Extraction". Applied Mechanics and Materials 519-520 (fevereiro de 2014): 1144–48. http://dx.doi.org/10.4028/www.scientific.net/amm.519-520.1144.

Texto completo da fonte

Resumo:

The mud pulse signal extracting in MWD(Measurement while drilling) was a core technology in the oil drilling developing process. In terms of the extraction and recognition problems of weak mud pulse signal in MWD, this paper analyzed the transmission format of Manchester coded down-hole datum and transmission characteristics of mud pulse signal and used morphological filtering algorithm to extract the mud pulse signal. According to the characteristics of the Manchester coded underground synchronization signal. After determining the location of the signal start time, It proposed a pattern similar waveform-recognition algorithm to detect the mud pulse signal. The field tests show that the algorithm can accurately define the mud pulse signal starting time and can effectively improve the decoding accuracy and meet the requirements of engineering applications.

Estilos ABNT, Harvard, Vancouver, APA, etc.

46

Rosli, Siti Julia, Hasliza Rahim, Ruzelita Ngadiran, K. N. Abdul Rani, Muhammad Imran Ahmad e Wee Fwen Hoon. "Design of Binary Coded Pulse Trains with Good Autocorrelation Properties for Radar Communications". MATEC Web of Conferences 150 (2018): 06016. http://dx.doi.org/10.1051/matecconf/201815006016.

Texto completo da fonte

Resumo:

Finite length of sequences that are modulated both in phase and amplitude and have an ideal autocorrelation function (ACF) consisting of merely a pulse have many applications in control and communication systems. They are widely applied in control and communication systems, such as in pulse compression systems for radar and deep-space ranging problems [1-5]. In radar design, the important part is to choose a waveform, which is suitable to be transmitted because the waveform controls resolution in clutter performance. In addition, it can solve a general signal problem particularly related to the digital processing. Energy ratio (ER), total side lobe energy (SLE), and peak sidelobe level (PSL) are three properties of such sequences interest. This paper presents a method using the Complementation, Cyclic Shift and Bit Addition for synthesizing and optimizing a binary sequence implemented to improve the sequences of a similar quality with the Barker sequence, particularly for lengths greater than 13. All of these methods are guided by the specific parameter with good characteristics in ACF (ER, SLE, and PSL) [6,7,8]. Such sequences can then be effectively used to improve the range and Doppler resolution of radars.

Estilos ABNT, Harvard, Vancouver, APA, etc.

47

Zahra, A. G., A. Youssef, M. Talha, F. M. Ahmed e W. Mehany. "Small RCS targets detection based on pulse compression radar signal generator and processor". Journal of Physics: Conference Series 2616, n.º 1 (1 de novembro de 2023): 012035. http://dx.doi.org/10.1088/1742-6596/2616/1/012035.

Texto completo da fonte

Resumo:

Abstract In the last two decades, field programmable gate arrays (FPGAs) have become the leading technology for implementing real time systems, specially radars. The most important advantage of FPGA is its parallel nature of executing complicated algorithms. As a result, the received data flow will be processed in a real time manner, which is suitable for radar applications. This paper attempts to show the design and the FPGA implementation of a binary phase-coded pulse compression radar signal generator and processor, that are intended to determine the ranges, and the speeds of targets with small radar cross-section area like drones. The system operating waveform is a bi-phase sequence, that is known to have the best known peak sidelobe level compared to compound Barker codes of the same length. In addition, the design incorporates a range sidelobes cancellation method to remove the time sidelobes in the matched filter output. Also, we are going to represent and investigate the FPGA implementing steps of the radar waveform generator and processor according to the required parameters. Finally, the implementation results of the proposed system will be represented.

Estilos ABNT, Harvard, Vancouver, APA, etc.

48

Leonard, Batende Vwikalo, e Denesh Sooriamoorthy. "A study on transfer function to estimate the central aortic blood pressure waveform". Journal of Physics: Conference Series 2523, n.º 1 (1 de julho de 2023): 012022. http://dx.doi.org/10.1088/1742-6596/2523/1/012022.

Texto completo da fonte

Resumo:

Abstract Noninvasive measurement of the central aortic blood pressure has become an important technique that has generated a lot of interest around the medicine industry because it can estimate the central aortic blood pressure waveform without inserting a pressure-sensing catheter into the ascending aorta. The accuracy of noninvasive estimation of aortic hemodynamics and cardiac contractility is still debatable in noninvasive measurement of the central aortic blood methods. The objective of this project is to investigate the transfer functions available for converting radial blood pressure waveforms to central aortic blood pressure waveforms. In this project, three different transfer functions will be investigated which are The Generalized Transfer Function, N-Point Moving Average and Adaptive Transfer Function in order to recommend the effective method in terms of accuracy. The study methodology will be conducted through the software MATLAB R2021b. The investigation of these three methods will be conducted with data collected from virtual subjects from the HaeMod database. The Generalized transfer function, N-Point Moving Average and Adaptive Transfer Function will be coded, evaluated, and analyzed as part of the methodology. The determination of the most effective method among the three transfer functions will be attributed according to output comparison of Systolic peak differences, the RMSE and the MAPE between the estimated central aortic blood pressure and the measured central aortic blood pressure.

Estilos ABNT, Harvard, Vancouver, APA, etc.

49

Zhen, DU, ZHANG Zenghui e YU Wenxian. "A Multicarrier Phase‐Coded Waveform Design Scheme for Joint Radar and Communication System". Chinese Journal of Electronics 30, n.º 4 (julho de 2021): 769–80. http://dx.doi.org/10.1049/cje.2021.05.020.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

50

Gao, Liang, Xiangfei Chen e Jianping Yao. "Photonic Generation of a Phase-Coded Microwave Waveform With Ultrawide Frequency Tunable Range". IEEE Photonics Technology Letters 25, n.º 10 (maio de 2013): 899–902. http://dx.doi.org/10.1109/lpt.2013.2253455.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Artigos de revistas sobre o tema "Coded waveform"

Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos