共查询到19条相似文献,搜索用时 125 毫秒
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机载MIMO雷达广义最大似然检测器 总被引:1,自引:1,他引:0
该文针对机载MIMO雷达在未知统计特性的杂波中目标检测问题,首先给出广义最大似然(GLRT)检测器(MIMO-GLRT),利用MIMO雷达的空间分集特性提高检测性能,并推导出检测概率和虚警概率表达式。然后,基于MIMO雷达杂波协方差矩阵的块对角特性,给出一种简化MIMO-GLRT检测器,大大减小算法的复杂度,同时降低对参考单元数目的要求,并在只有两个接收雷达单元的情形下,推导出简化GLRT检测性能的表达式。结果表明,上述两种检测器相对于杂波协方差矩阵都具有恒虚警特性,能够在未知杂波背景下有效地检测目标。 相似文献
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传统集中式多输入多输出(MIMO)雷达自适应检测器虽然不需要训练样本即可实现目标检测,但在波形采样数较少时检测性能下降明显。该文利用集中式MIMO雷达噪声协方差矩阵的斜对称结构,基于广义似然比(Generalized Likelihood Ratio Test, GLRT)准则和Wald准则,提出了相应的斜对称检测器,并给出了统计分布特性及检测概率和虚警概率的解析表达式。仿真结果表明所提检测器在波形采样数较少时仍可获得较好的检测性能,同时证明了理论分析的正确性。 相似文献
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针对频率分集条件下,集中式OFDM-MIMO雷达在未知杂波环境中的目标检测问题,首先分析了OFDM-MIMO雷达回波数据模型,由于OFDM-MIMO雷达的频率分集特性,不同频率通道回波数据相互独立,在此基础上,分别基于一步和两步广义最大似然比准则,给出了集中式OFDM-MIMO雷达GLRT和OFDM-MIMO雷达AMF两种检测器,并分析了这两种检测器的恒虚警特性。两种检测器有效利用集中式OFDM-MIMO雷达频率分集特性,提升目标检测性能,同时降低了矩阵求逆维数,以及参考单元数目的要求,并且具有恒虚警性能。计算机仿真验证了算法的有效性。 相似文献
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研究了分布式目标在球不变随机变量杂波中的检测问题,提出了一种具有恒虚警特性的双门限广义似然比检测器。分布式目标建模为子空间信号,在距离维和多普勒频率维同时扩展.第一门限的作用是筛选信杂比高的待检测距离单元.将选出的距离单元进行能量积累并与第二门限进行比较做出判决.假设杂波协方差矩阵已知,构造了双门限检测器,并通过推导检测器虚警概率说明其具有恒虚警特性.将基于辅助通道数据的杂波协方差矩阵的估计值替换假设已知的杂波协方差矩阵,得到一个自适应检测器.通过Monte Carlo仿真进行性能分析,说明检测器的有效性和鲁棒性. 相似文献
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针对传统协方差矩阵估计方法忽略了海杂波的统计一致性随雷达距离分辨率的变化而变化以及可积累脉冲受参考样本数量的限制这两个问题,提出了一种基于对角加载的协方差矩阵估计算法,其加载系数随着杂波向量的一致性变化而自适应地变化.改进的估计矩阵相对误差小,条件数好,加载系数为近似最优.实测海杂波数据实验表明,使用改进的估计算法使检测器的性能有明显改善. 相似文献
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一种基于有序统计的MIMO雷达CFAR检测器 总被引:1,自引:1,他引:0
针对多输入多输出(MIMO)雷达的体制特点,提出了一种基于有序统计的MIMO雷达CFAR检测器(LCIOSOS-CFAR),给出了虚警概率与检测概率的表达式;然后在各种杂波背景下对检测器性能进行了仿真分析,并与经典的CA-CFAR检测器进行比较.仿真结果表明,LCIOSOS-CFAR检测器在均匀杂波背景下较CA-CFAR有较小损失,在多目标干扰环境下较CA-CFAR性能改善明显,在杂波边缘背景下虚警峰值小于CA-CFAR,实际应用中具有较强的鲁棒性.文中还分析了序值选取对LCIOSOS-CFAR检测性能的影响. 相似文献
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Jeong Hwan Shin Kwangseok Noh Wonjin Sung Jun Heo 《Wireless Personal Communications》2012,62(4):923-936
In this paper we design an irregular low-density parity-check (LDPC) code for multiple-input multiple-output (MIMO) systems,
using a simple extrinsic information transfer (EXIT) chart method. The MIMO systems considered are the optimal maximum a posteriori
probability (MAP) detector and the suboptimal minimum mean square error soft-interference cancellation (MMSE-SIC) detector.
The MIMO detector and the LDPC decoder exchange soft information and form a turbo iterative receiver. The EXIT charts are
used to obtain the edge degree distribution of the irregular LDPC code which is optimized for the MIMO detector. It is shown
that the performance of the designed LDPC code is better than that of conventional LDPC code which was optimized for either
the Additive White Gaussian Noise (AWGN) channel or the MIMO channel without an explicit consideration of the given detector
structure. 相似文献
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The equivalent diversity order of iterative minimum mean squared error (MMSE) multiuser detectors for multiple input multiple output (MIMO) channels is decreased if they aim at suppressing unknown cochannel interference (UCCI) while detecting multiple users' signals. In this letter, we propose a new MIMO signal detection scheme with the aim to preserve the detector's diversity order by estimating the probability density function of the UCCI plus background noise. It is shown that the proposed detector significantly outperforms the conventional detector based on UCCI's covariance matrix estimation. 相似文献
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本文考虑了色高斯干扰条件下MIMO STAP稳健波形优化问题以提高非完备杂波先验知识条件下多输入多输出(MIMO)雷达体制下空时自适应处理(STAP)最坏情况下探测性能。由于高斯干扰(包括杂波、干扰以及热噪声)场景下最大化系统输出信干噪比(SINR)等价于最大化MIMO STAP检测性能,因而在本文所建立杂波协方差估计误差的模型基础上,总功率发射以及参数不确定凸集约束下,经推导可得稳健波形优化问题。为求解得到的复杂非线性问题,本文提出了一种迭代算法以优化发射波形相关阵(WCM)从而最大化凸不确定集上最差情况下的输出SINR进而改善最差情况下MIMO STAP的检测性能。通过利用对角加载(DL)方法,所提算法中的每个迭代步骤皆可表示为能获得高效求解的半定规划(SDP)问题。与非稳健方法及非相关波形相比,数值实验验证了本文所提方法的有效性。 相似文献
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Jalden J. Barbero L.G. Ottersten B. Thompson J.S. 《Signal Processing, IEEE Transactions on》2009,57(7):2711-2720
The fixed-complexity sphere decoder (FSD) has been previously proposed for multiple-input multiple-output (MIMO) detection in order to overcome the two main drawbacks of the sphere decoder (SD), namely its variable complexity and its sequential structure. Although the FSD has shown remarkable quasi-maximum-likelihood (ML) performance and has resulted in a highly optimized real-time implementation, no analytical study of its performance existed for an arbitrary MIMO system. Herein, the error probability of the FSD is analyzed, proving that it achieves the same diversity as the maximum-likelihood detector (MLD) independent of the constellation used. In addition, it can also asymptotically yield ML performance in the high-signal-to-noise ratio (SNR) regime. Those two results, together with its fixed complexity, make the FSD a very promising algorithm for uncoded MIMO detection. 相似文献
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Michael Wu Yang Sun Siddharth Gupta Joseph R. Cavallaro 《Journal of Signal Processing Systems》2011,64(1):123-136
Multiple-input multiple-output (MIMO) significantly increases the throughput of a communication system by employing multiple antennas at the transmitter and the receiver. To extract maximum performance from a MIMO system, a computationally intensive search based detector is needed. To meet the challenge of MIMO detection, typical suboptimal MIMO detectors are ASIC or FPGA designs. We aim to show that a MIMO detector on Graphic processor unit (GPU), a low-cost parallel programmable co-processor, can achieve high throughput and can serve as an alternative to ASIC/FPGA designs. However, careful architecture aware software design is needed to leverage the performance offered by GPU. We propose a novel soft MIMO detection algorithm, multi-pass trellis traversal (MTT), and show that we can achieve ASIC/FPGA-like performance and handle different configurations in software on GPU. The proposed design can be used to accelerate wireless physical layer simulations and to offload MIMO detection processing in wireless testbed platforms. 相似文献
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In this letter, we address the problem of waveform optimization for multi-input multi-output (MIMO) space-time adaptive processing (STAP) in the presence of colored Gaussian disturbance. A novel diagonal loading (DL) based method is proposed to optimize the waveform covariance matrix (WCM) for maximizing the output signal-interference-noise ratio (SINR) of MIMO-STAP such that the detection performance can be maximized. The resultant nonlinear optimization problem is reformulated as a semidefinite programming (SDP) one, which can be solved very efficiently. Simulation results show that the output SINR of MIMO-STAP can be improved considerably by the proposed method, as compared to that of uncorrelated waveforms. 相似文献