2012 International Waveform Diversity & Design Conference (WDD)最新文献

{"title":"Using the conjugate gradient algorithm for reduced-rank adaptive detection","authors":"Zhu Chen, Hongbin Li, M. Rangaswamy","doi":"10.1109/WDD.2012.7311258","DOIUrl":"https://doi.org/10.1109/WDD.2012.7311258","url":null,"abstract":"In this paper, we introduce a group of reduced-rank (RR) space-time adaptive processing (STAP) detectors based on the conjugate gradient (CG) algorithm. The CG algorithm can be used for efficient calculation of the weight vector of several well-known STAP detectors. As an iterative algorithm, it produces a series of approximations to the fully adaptive solution, each of which can be used to filter the test signal and form a test statistic. This effectively leads to a family of RR adaptive detectors, referred to as the CG-RR detectors, which are indexed by k the number of iterations incurred. Performance of the proposed CG-RR detectors are examined in terms of the output signal-to-interference-plus-noise ratio (SINR). The conventional RR methods for STAP such as the data-independent DFT or DCT based rank reduction, the adaptive eigencanceler and cross-spectral metric (CSM) algorithm are also considered here. Simulation results show that the computationally efficient CG-RR detector often reaches the peak output SINR with a lower rank compared with the eigencanceler and CSM based detectors.","PeriodicalId":102625,"journal":{"name":"2012 International Waveform Diversity & Design Conference (WDD)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134348864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Moving target detection using distributed MIMO radar in non-homogeneous clutter: A subspace approach","authors":"Pu Wang, Hongbin Li, B. Himed","doi":"10.1109/WDD.2012.7311298","DOIUrl":"https://doi.org/10.1109/WDD.2012.7311298","url":null,"abstract":"Motivated by the fact that the multi-static transmit-receive configuration in a distributed multiple-input multiple-output (MIMO) radar causes non-stationary clutter, we consider the problem of moving target detection (MTD) using a distributed MIMO radar in non-homogeneous clutter environments. A new non-homogeneous clutter model, where the clutter resides in a low-rank subspace with different subspace coefficients for different transmit-receive pairs, is introduced. The subspace clutter model is effective in capturing the non-homogeneity of the clutter and, in particular, the power variations across different aspect angles and resolution cells. A generalized likelihood ratio test (GLRT), which performs local matched subspace detection, noncoherent combining using local decision variables of all transmit-receive pairs and target velocity matching, is proposed. The GLRT is shown to be a constant false alarm rate (CFAR) detector. Computer simulations are provided to verify our statistical analysis of the GLRT, and a comparison with existing detectors is conducted to evaluate the impact of model mismatch on detection performance.","PeriodicalId":102625,"journal":{"name":"2012 International Waveform Diversity & Design Conference (WDD)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126293341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Consensus-based wireless tomography","authors":"Z. Hu, G. Scalzi, M. Wicks, R. Qiu","doi":"10.1109/WDD.2012.7311280","DOIUrl":"https://doi.org/10.1109/WDD.2012.7311280","url":null,"abstract":"This paper, one in a series on new initiatives in wireless tomography, combines two areas: wireless communication and radio tomography. This paper discusses implementation of wireless tomography in a distributed architecture. Each sensor node in the wireless tomography system solves the local optimization problem to get the image and shares its own imaging result to all the other sensor nodes. The imaging results from all the sensor nodes will converge to the final image by iterations. Alternating direction method of multipliers (ADMM) will be explored in the paper to solve the consensus-based optimization. Consensus-based wireless tomography can distribute the computing workload among all the sensor nodes. The centralized computing engine is not needed. In this way, the wireless tomography system is scalable and robust with a large number of sensor nodes.","PeriodicalId":102625,"journal":{"name":"2012 International Waveform Diversity & Design Conference (WDD)","volume":"1039 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123140160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A test platform for real-time waveform and impedance optimization in microwave radar systems","authors":"C. Baylis, Joshua Martin, M. Moldovan, Obiageli Akinbule, R. Marks","doi":"10.1109/WDD.2012.7311307","DOIUrl":"https://doi.org/10.1109/WDD.2012.7311307","url":null,"abstract":"A test platform has been constructed at Baylor University to develop methods of simultaneous waveform and circuit optimization for cognitive radar. The ultimate goal of this work is to allow on-chip, simultaneous optimization of the waveform and the load impedance of the transmitter power amplifier from an FPGA cognitive-radio platform. The test bed includes a vector signal generator, load-pull tuners, a DC power supply, a power meter, and a spectrum analyzer, all controllable by MATLAB. The power meter and DC power supply are used to measure the power efficiency of the device under test, while the spectrum analyzer can be used to assess the spectral spreading, and hence linearity, of the device, through measurement of adjacent-channel power ratio or other means. Computationally intelligent routines for both load-impedance and waveform optimization will be created and evaluated using the test bed.","PeriodicalId":102625,"journal":{"name":"2012 International Waveform Diversity & Design Conference (WDD)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133304147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Frequency-hopping code design for colocated MIMO radar using sparse modeling","authors":"S. Gogineni, A. Nehorai","doi":"10.1109/WDD.2012.7311282","DOIUrl":"https://doi.org/10.1109/WDD.2012.7311282","url":null,"abstract":"We consider the problem of multiple target estimation using a colocated Multiple Input Multiple Output (MIMO) radar system. We employ sparse modeling to estimate the unknown target parameters (delay, Doppler) using a MIMO radar system that transmits frequency-hopping waveforms. We derive analytical expressions for the correlations between the different blocks of columns of the sensing matrix. Using these expressions, we compute the block coherence measure of the dictionary. Next, we use this measure to optimally design the sensing matrix by selecting the hopping-frequencies for all the transmitters. We demonstrate the performance improvement using numerical simulations.","PeriodicalId":102625,"journal":{"name":"2012 International Waveform Diversity & Design Conference (WDD)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132077319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive noise processing of a virtual beam formed radar","authors":"S. Kadlec","doi":"10.1109/WDD.2012.7311275","DOIUrl":"https://doi.org/10.1109/WDD.2012.7311275","url":null,"abstract":"An adaptive filter specifically designed to process noise phase-shift keyed waveforms is demonstrated to replicate the least squares estimate of the scattering scene to within the error of the least squares estimate. Thus, the clutter (or multiplicative noise) is statistically no worse than the clutter produced by solving the least squares problem while the computational complexity is greatly reduced. The filter is derived using the statistical properties of the noise waveform, and is, therefore, tuned for this waveform. One benefit of the filter presented here over other adaptive filters is the lack of a step-size parameter. The ideal choice of the step-size parameter requires knowledge of the SNR. Without a priori knowledge of the radar cross section, the step-size parameter is misestimated causing traditional adaptive filters to converge slowly, or worse, diverge. This new adaptive noise filter (ANF) has been demonstrated in a simulated Multiple Input, Multiple Output (MIMO) architecture employing a set of mutually orthogonal quadraphase noise waveforms (QPN). The transmit and receive elements are collocated to form a single dense array. The orthogonality of the waveforms results in a transmitted beam which is unfocused, covering a wide region. The ANF is used to simultaneously isolate the return by transmit element and to range compress the return. Next, virtual beam forming (VBF) processing is applied to realize both the transmit and the receive antenna gain and beam steering. This gain is compared with the result of a traditional electronically steered array (ESA) employing a single waveform and verified to be identical [1]. The signal to interference noise ratio (SIR) is quantified in the range dimension as a function of the number of waveforms employed, the number of chips processed, and size of the range swath. It was found that the SIR in the VBF output is not adversely dependent on the number of simultaneous transmitters. The number of simultaneous transmitters and, thus, the illuminated region can, therefore, be increased constrained by neither additive nor multiplicative noise.","PeriodicalId":102625,"journal":{"name":"2012 International Waveform Diversity & Design Conference (WDD)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134305067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of SINR loss for waveform design of known-target in signal-dependent interference","authors":"Lulu Wang, Hong-qiang Wang, Yu-liang Qin, Yongqiang Cheng","doi":"10.1109/WDD.2012.7311316","DOIUrl":"https://doi.org/10.1109/WDD.2012.7311316","url":null,"abstract":"Assuming the target impulse response to be known or to be a stochastic process with some PSD (Power Spectrum Density) is a basic assumption in most of the recently proposed waveform design algorithms. However, it is well-known that target impulse response is not easily and accurately obtained; besides it changes sharply with the attitude angle, both of which complicate the waveform design process. In this paper, SINR loss is analyzed which takes into account the uncertainty of the target impulse response. Results show that SINR loss fluctuates slightly with the error variance of the target impulse response which illustrates the robustness of the waveform design algorithm, as well as the fact that SINR loss is great if signal energy is small under same uncertainty of target impulse response which inspires us the necessity of optimizing waveforms under small energy constraint. Results are meaningful for waveform design methods.","PeriodicalId":102625,"journal":{"name":"2012 International Waveform Diversity & Design Conference (WDD)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114912890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}