共查询到18条相似文献,搜索用时 156 毫秒
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在干扰背景下,集中式MIMO雷达可以通过设计发射波形提高系统的输出信干噪比,然而优化后的波形通常会具有较高的自相关旁瓣,降低了接收机对弱目标的检测性能。该文提出一种干扰背景下MIMO雷达部分相关信号设计方法。该方法在兼顾发射信号峰均比(PAPR)的同时,在发射天线对正交恒模波形进行加权处理,并以最大化接收机系统的输出信干噪比为准则建立目标函数,给出一种基于拟牛顿法的连续优化算法求解目标函数,获得最优加权,使得系统的输出信干噪比得到提升。仿真结果表明,该方法能够有效地抑制干扰,并可自适应地将发射信号能量辐射向目标方向,提高系统输出信干噪比。 相似文献
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研究了一种基于Hermite脉冲的超宽带系统在多径信道下的性能。考虑到定时抖动对Rake相关接收的影响,通过Hermite脉冲的相关函数可以计算Rake捕获的信号能量,进而得到接收机的输出信干比。在假设符号间干扰为高斯噪声下,得出系统在多径信道下的理论误比特性能。结果表明,符号间干扰能量对Rake接收机合并路径数目的变化并不敏感;增加合并路径数目可以提高系统的误比特性能;大的定时抖动范围会造成系统性能下降。 相似文献
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串行干扰相消接收机是广泛应用于多输入多输出系统中的一种接收端信号处理与检测技术。在串行干扰相消接收机中,先检测的层的判决准确性会对后续层的检测产生影响。检测过程中产生的判决误差,将对后续层的检测引入残留干扰,进而影响后续层检测的正确性,造成差错传播。本文提出一种基于软判决的最小均方误差检测带排序串行干扰相消接收机,可以有效减轻基于硬判决方法的带排序串行干扰相消接收机的差错传播问题。在重构干扰信号时,该接收机使用根据软判决信息得到的符号期望,替代硬判决方法,能够有效降低干扰相消时各层之间由判决误差引起的残留干扰;该接收机还可以精确估计残留干扰的功率以及各层数据流的后处理信干噪比,改善了基于硬判决方法的串行干扰相消接收机存在的各层后处理信干噪比估计值偏大的问题。可靠性更高的软判决结果有效降低了残留干扰,更精确的各层后处理信干噪比抑制了残留干扰对后续数据流检测的影响,提高了判决结果和排序过程的准确性。仿真结果证明,基于软判决的最小均方误差检测带排序串行干扰相消接收机可以有效避免差错传播的产生,因而获得较大的性能提升。 相似文献
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改进的GPS抗干扰自适应天线阵性能研究 总被引:2,自引:1,他引:1
文章提出了一种用于GPS接收机的新型抗干扰自适应天线阵,并给出了对其方向图和输出信干噪比的仿真过程.比较了在相同的信号环境时,该天线阵与常用的均匀直线阵、等间隔圆形阵的性能.结果表明,使用该自适应阵可以改善天线阵的方向图,提高输出信号干扰噪声比SINR,增强接收机的抗干扰能力. 相似文献
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针对卫星导航接收机时域窄带干扰的有效抑制问题,本文首先给出二阶格型IIR陷波器参数设计方法,通过陷波带宽的定量调整,既可以有效抑制窄带干扰,又可以降低卫星信号的失真;其次推导了二阶IIR格型陷波器相关输出信干噪比改善因子的闭合表达式,该表达式相比干扰抑制后信干噪比的改善,更为直观地反映了陷波器对卫星导航信号的影响。理论分析和仿真实验,二阶格型IIR陷波器相关输出信干噪比改善因子与陷波器的带宽参数有关,而与陷波频率无关,且二阶格型IIR陷波器的性能优于最优线性预测Wiener滤波器、最优线性插值Wiener滤波器、五系数FIR滤波器以及二阶直接型IIR陷波器。 相似文献
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传统空时自适应处理(STAP)算法不能抑制和导航信号同一方向的窄带干扰并且输出信干噪比不理想。针对此问题,本文提出了一种结合加权波束的改进STAP抗干扰算法。这种新的算法能有效地抑制窄带和宽带干扰,并提升了输出信干噪比(SINR)。 相似文献
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抑制干扰是电子战和信息处理的号的带宽受到大量的广播电台、短波通信干扰的限制,很难找到较宽的且未被污染的干净频带,因此导致了接收机端很低的信干噪比,较为理想的方法是在一定的带宽要求下抑制干扰,为此我们提出了一种基于频域滤波的高自适应的窄带干扰抑制方法.计算机仿真结果表明:该方法可以有效地提高接收机的信干噪比,从而实现了大幅度改善雷达发现和检测目标的能力. 相似文献
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In this article, a method based on max signal interference noise ratio (SINR) criterion is proposed, to mitigate the interuser interference for downlink multiuser spatial multiplexing multi-input multi-output (MIMO) systems.Unlike the zero forcing (ZF) scheme in which the SNR is decreased when the interference is eliminated completely, max SINR method makes a compromise between noise and interuser interference.When the number of substreams is larger than the difference between the number of base station antennas and the sum of interference mobile station antennas, the ZF is infeasible.An existing coordinated TX-RX block diagonalization (COOR BD) method uses preprocessing at the receiver to cancel the interuser interference.However, it cannot obtain more receive diversity gain because of the preprocessing.Analysis and simulation show that the max SINR scheme has better performance than the ZF method.Moreover, when the ZF is infeasible, the max SINR scheme can obtain more receive diversity gain than COOR BD in the two-user case. 相似文献
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Combined spatial and time-frequency signatures of signal arrivals at a multisensor array are used for nonstationary interference suppression in direct-sequence spread-spectrum (DS/SS) communications. With random PN spreading code and deterministic nonstationary interferers, the use of antenna arrays offers increased DS/SS signal dimensionality relative to the interferers. Interference mitigation through a spatio-temporal subspace projection technique leads to reduced DS/SS signal distortion and improved performance over the case of a single antenna receiver. The angular separation between the interference and desired signals is shown to play a fundamental role in trading off the contribution of the spatial and time-frequency signatures to the interference mitigation process. The expressions of the receiver signal-to-interference-noise ratio (SINR) implementing subspace projections are derived, and numerical results are provided 相似文献
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Lars T. Berger Troels E. Kolding Laurent Schumacher Preben E. Mogensen 《Wireless Personal Communications》2007,40(3):343-354
Link level SINR simulation results and network level sector throughput simulation results that quantify the benefit of dual
antenna MMSE reception in a macrocellular WCDMA/HSDPA system are provided. Dual antenna RAKE receiver performance serves as
baseline reference. Link-level simulation results are accompanied by a novel analytical expression that in flat Rayleigh fading
and for uncorrelated rx-antenna branches describes spatial interference suppression mean SINR gain as function of a dominant other-sector interference ratio (DIR). It is shown that the MMSE receiver’s spatial interference suppression gain heavily depends on the amount of experienced
DIR. The higher the DIR the higher the SINR gain. Nevertheless, seen on network level the SINR gain turns into moderate sector
throughput gain, well below 50%. This is due to the fact that high DIR situations are rare in the investigated macrocellular
scenario. Moreover, the logarithmic relation between SINR and capacity hinders translation of the full SINR gain into HSDPA
sector throughput. 相似文献
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该文研究了极化敏感阵列采用斜投影滤波和正交投影滤波的输出信干噪比(SINR)特性。推导获得了斜投影滤波与正交投影滤波在理想情况和存在阵列误差时的输出SINR 计算式:理想情况下输出SINR 是信噪比(SNR)、目标与干扰的空域和极化域匹配系数的函数;存在阵列误差情况时输出SINR 受信噪比,干噪比(INR)、目标与干扰的空域-极化域匹配系数及误差扰动量共同影响。分析表明,相比正交投影滤波而言,斜投影滤波的输出SINR没有改善,也不能提高误差稳健性,它们均低于最优输出SINR;正交投影与斜投影输出SINR 相同的成因并不一样,正交投影滤波改变了目标的幅相特性,滤波后目标有损失;斜投影滤波改变了输出噪声的空域-极化域特性,放大了输出噪声的功率。最后通过仿真实验验证了理论分析的正确性。 相似文献
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Transmit-antenna selection for spatial multiplexing with ordered successive interference cancellation 总被引:1,自引:0,他引:1
This letter proposes a low-complexity algorithm for transmit-antenna selection in a multi-input multi-output spatial multiplexing system with per-antenna rate control and an ordered successive interference cancellation receiver. The active antenna subset and its transmission rate are determined at the receiver, and conveyed to the transmitter using limited feedback. We propose a serial antenna-selection procedure consisting of a successive process that tests whether transmit-antenna selection gain exists when the antenna with the lowest signal-to-interference-plus-noise ratio (SINR) is discarded at each selection stage. Furthermore, we show that "reverse-detection ordering", whereby the signal with the lowest SINR is decoded at each stage of successive decoding, widens the disparities among fractions of the whole capacity allocated to each individual antenna, and thus maximizes a gain of antenna selection. Numerical results show that the proposed reverse-detection-ordering-based serial antenna selection induces a negligible capacity loss, compared with the exhaustive selection strategy, even with considerably reduced complexity. 相似文献