共查询到18条相似文献,搜索用时 140 毫秒
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非均匀天线组阵SUMPLE合成相位补偿及信号强度估计 总被引:2,自引:0,他引:2
SUMPLE相关算法是深空网天线组阵中信号合成最重要的方法之一.在对SUMPLE相关算法分析的基础上,将均匀天线阵SUMPLE相位漂移补偿方法推广到了非均匀天线阵.根据权值系数的计算方法,提出一种非均匀阵各天线信号强度的估计算法.理论分析与仿真结果表明,所推导的相位补偿方法能有效消除非均匀阵合成信号的相位漂移问题;所提出的天线信号强度估计方法具有较高的估计精度.进行补偿相位估计时,应对权值系数进行低通或卡尔曼滤波,以降低权值系数的随机噪声. 相似文献
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天线组阵技术是提高深空探测微弱信号信噪比的有效方法。随着大规模天线组阵中单个天线接收信号信噪比的降低,来自背景天体的相关噪声的影响不容忽视。针对相关噪声对天线组阵SUMPLE算法权值估计的影响进行了分析,给出了一种基于频域的抑制相关噪声影响的处理方法。计算机仿真结果表明:在相关噪声背景下,该方法能有效地提高SUMPLE算法权值相位的估计精度,抑制相关噪声的干扰。 相似文献
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为对深空网天线组阵中几种相关合成算法进行分析比较,构建了一种新的Simulink仿真模型。将其应用于某测控站天线组阵试验数据,验证了模型的可行性。在此仿真模型下,对Simple、Sumple和Matrix-free 算法进行了频标同源/频标不同源、弱信号/强信号、2/3/6个天线等组阵情况下的仿真分析。三种算法在频标同源情况下的合成效率均优于不同源的情况;强信号组阵情况下,三种算法的信噪比合成性能基本相当;Simple算法在6天线情况下,信噪比合成性能下降;Sumple算法在组阵的天线数目很少时,合成信噪比较低且不稳定,在天线数目较多时性能良好;Matrix-free算法性能稳健,合成效率始终大于95%。该Simulink仿真模型对于进行天线组阵信号相关算法的分析具有一定的价值。 相似文献
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深空探测的发展对信噪比的要求越来越高,异地天线组阵利用现有天线设施合成信号,显著提高信号SNR。针对异地天线组阵基线长、钟差大和信号到达时间不一致等特点对异地天线组阵信号合成效率的影响,结合现有集群结构的性能,给出天线组阵信号合成并行算法与Sumple算法相结合的处理方案,并在计算仿真中心上实现4路组阵信号全频谱合成,理论上有6 dB的增益。 相似文献
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针对多天线信号合成系统对于宽带、高速、并行信号的实时合成需求,设计了基于图形处理单元(Graphics Processing Unit,GPU)的宽带信号时延差与相位差估计方法,对估计方法中的快速傅里叶变换(Fast Fourier Transform,FFT)、共轭相乘、累加平均等模块进行了相应的线程并行程序设计。为充分发挥GPU的并行运算能力,利用异步流并发的方式对估计方法进一步优化,从结构层面有效提高了数据的并行处理效率。对基于GPU的宽带信号时延差与相位差估计方法进行了实验验证,多次实验测试结果表明,数据量为512 000时,在保证估计正确性的基础上,该方法相比传统串行CPU估计方法约有125倍的加速比,采用该方法可实现对多天线信号参数的实时估计。 相似文献
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在卫星通信中,由于星上资源有限,导致星载信号处理接收机的数目一般少于阵列天线的阵元数.在某些应用中需要在这样的条件下实现DOA估计:信号达波数大于星载信号处理接收机数目但是可能小于阵列天线的阵元数.实质上是要求能够用较少数量的接收机进行接收、处理含有较多阵元的阵列天线上的信号.针对这类应用要求,本文提出一种基于子阵列合成的DOA估计算法.通过子阵列输出协方差矩阵合成等效的大阵列输出协方差矩阵,基于等效大阵列输出协方差矩阵实现达波DOA超分辨率估计;讨论了子阵列天线选择优化问题.对算法性能进行了仿真验证,结果表明算法是有效的. 相似文献
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A multireceiver configuration for the purpose of carrier arraying and/or signal arraying is presented. The configuration is arrived at by formulating the carrier and/or signal arraying problem as an optimal estimation problem and consists of two stages. The first stage optimally estimates various phase processes received at different receivers with coupled phase-locked loops, (PLL) wherein the individual PLLs acquire and track their respective receivers' phase processes but are aided by each other in an optimal manner via low-frequency error signals. The coupled PLL estimator is followed by a linear or nonlinear combining of the quadrature-phase components of the mixers from various receivers for the purpose of data detection. The proposed configuration results in the minimization of the effective radio loss as the combiner output and thus maximization of energy per bit to noise power spectral density ratio is achieved. An adaptive algorithm for the estimator of the signal model parameters when these are not known a priori is also presented 相似文献
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Fast DOA estimation algorithm using pseudocovariance matrix 总被引:1,自引:0,他引:1
Jung-Tae Kim Sung-Hoon Moon Dong Seog Han Myeong-Je Cho 《Antennas and Propagation, IEEE Transactions on》2005,53(4):1346-1351
This paper proposes a new direction of arrival (DOA) estimation algorithm that can rapidly estimate the DOAs of incidence signals using a pseudocovariance matrix even under coherent interference environments. The conventional multiple signal classification (MUSIC) algorithm, which should estimate a covariance matrix, cannot perform a DOA estimation until it acquires the covariance matrix. In addition, the MUSIC algorithm cannot be used under rapidly changing or correlated interference environments. In contrast, the proposed algorithm can obtain a bearing response after acquiring the pseudocovariance matrix based on a single snapshot. Signal incidence angles can then be accurately estimated by combining the bearing response and the location of pattern s. Accordingly, the proposed algorithm can rapidly estimate the DOAs of signals even when they are correlated. 相似文献
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针对L频段数字航空通信系统1(L-DACS1)以内嵌方式部署在航空无线电导航频段而产生的高强度测距仪脉冲信号干扰正交频分复用(OFDM)接收机问题,提出联合正交投影与CLEAN的测距仪脉冲干扰抑制方法。接收机首先通过将接收信号矢量投影到干扰信号正交补空间的方法消除高强度测距仪脉冲干扰,然后利用OFDM信号循环前缀的对称特性,采用CLEAN算法估计信号来向,然后通过波束成形提取OFDM直射径信号。计算机仿真表明:论文提出方法可有效克服测距仪脉冲及OFDM散射径信号的干扰,提高L频段数字航空通信系统1的链路传输的可靠性。 相似文献
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突发信号盲检测在非合作通信中至关重要。待检测信号特征量的构造与突发信号段起止点的精确捕获是突发信号盲检测技术的关键。文中提出了一种基于循环谱的突发信号盲检测算法,算法首先以循环谱循环频率截面的相对方差作为待检测信号的特征量,该特征量具有优良的抑制突发强噪声干扰性能;然后利用特征量的方差进行信号存在性判决;最后采用基于特征量峰值的突发信号段起止点搜索算法,避免了设置检测门限带来的信噪比估计、噪声功率估计等问题,同时可在一定的检测正确率条件下保证起止点的捕获精度。仿真结果表明,该算法能有效抑制突发强噪声干扰,信号存在性判决准确率高,而且在误差控制要求较严格条件下的检测精度优于双窗能量法。 相似文献
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With the development of wireless and personal communication systems, there is considerable interest in using antenna array technology to improve the system capacity in both present and future generation wireless systems. A novel and simple algorithm is proposed for blind adaptive extraction of a binary phase-shift keying (BPSK) signal in the presence of interference by cyclostationary signal processing using an antenna array. The algorithm operates in an interference-limited system in which the desired and interfering signals have identical symbol rates, but are modulated on slightly different carrier frequencies. Compared to existing blind algorithms which also exploit the cyclostationarity of the received signal, the new algorithm provides a simpler and faster converging means to estimate the channel phase for diversity combining. Analytical and simulation results are presented and performances are compared with direct matrix inversion (DMI) and existing blind algorithms. Based on the proposed algorithm and the result obtained by Gardner, Schell and Murphy (1992), a time-division multiple-access (TDMA) system with the new channel assignment scheme called cyclic TDMA (CTDMA) is proposed. The simulation results also show that the proposed algorithm is relatively simple and very promising in applications to indoor wireless communication where interference rejection and increased spectrum efficiency are the objectives. Analysis and simulation results are presented to confirm the interference rejection capabilities. The robustness of existing and proposed algorithms to the perturbation of cyclostationarity is also discussed 相似文献
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A new nonparametric algorithm for the identification of linear time-invariant systems is proposed. The method is based on the cyclic correlations of the input and output signals with a nonlinear transformation of the input signal. Consequently, although it exploits the higher order cyclostationarity properties of the input and output signals, its computational complexity is comparable with that of methods based on second-order statistics. The proposed estimator of the system transfer function is inherently immune to the presence of noise and interference on both input and output signal measurements and turns out to be asymptotically unbiased and consistent. Moreover, bias and variance of the estimate exhibit a rate of convergence to zero equal to that of estimates based on second-order statistics. Finally, simulation results show that the proposed algorithm significantly outperforms, in terms of both bias and variance of the estimates, several nonparametric identification algorithms previously presented in the literature 相似文献
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以循环谱理论为基础,分析了直扩信号在平稳噪声及窄带干扰情况下的循环统计特性,研究了直扩信号的到达时差估计模型和提取方法。在单一循环频率的基础上,对算法进行改进,提出了全相干循环估计器的到达时差算法。通过计算机仿真,验证了改进算法不仅对信号具有选择能力,而且较单循环估计器和传统互相关方法具有更强的抑制噪声能力。最后通过仿真得到了估计性能曲线,验证了理论的正确性。 相似文献
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针对传统MQAM信号载频与符号率估计算法在脉冲噪声下性能不佳甚至失效的问题,该文结合分数低阶矩与共变理论,推导了MQAM的分数低阶循环谱密度函数,并分析了升余弦脉冲成型条件下的MQAM信号循环谱特征。将分数低阶矩引入离散频域平滑谱(DFSM)估计。提出了一种基于分数低阶矩的MQAM载波频率与符号率联合参数估计算法,采用相邻谱切面求平均的方法,有效的避免了由于分辨率不足造成估计误差。仿真实验结果表明,与二阶DFSM循环谱估计算法相比,本文算法不仅能够抑制脉冲噪声的影响,而且在较为恶劣的噪声条件下均能有效的估计MQAM信号的载频与符号率,具有更好的抗干扰能力与适用性,适用于不同调制阶数的MQAM信号。 相似文献