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1.
In this paper,a novel adaptive interference suppression algorithm is proposed for high dynamic GPS (global positioning system) receiver.The new method incorporates derivative constraints on the inter-ference DOA (direction of arrival) into power minimization approach,which could broaden the width of nulls in the interferences directions and adapt to the rapid change of the interference directions.Compared with the traditional wide nulling algorithm based on the derivative constraints,the new method does not have to know or estimate the DOAs of the desired signal and the interference.The new method is firstly discussed in the context of spatial processing,and then extended to space-time adaptive processing to mitigate wideband diffusive multipath interference.Effectiveness of the new method is verified via simulation examples. 相似文献
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本文提出了一种基于微分约束最小功率法的高动态全球定位系统(GPS)接收机的自适应抗干扰方法.该方法对最小功率法在干扰的来向上加微分约束,能够加宽天线波束在干扰来向上形成零陷的宽度,用以应对高动态环境中干扰波达方向随时间的快速变化.和常规的基于微分约束的加宽零陷方法相比,本文方法不需要知道或估计信号和干扰来向信息.本文不仅在空域探讨了该方法,还将该方法推广到空时二维自适应处理来抑制宽带色散多径干扰.仿真结果证明了该方法的有效性. 相似文献
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提出了基于无迹粒子滤波(UPF)算法的高动态GPS载波跟踪环路,仿真分析了该方案在高斯噪声和非高斯噪声环境下对高动态GPS信号的跟踪性能,并与分别基于扩展卡尔曼滤波(EKF)、无迹卡尔曼滤波(UKF)、粒子滤波(PF)及扩展卡尔曼粒子滤波(EPF)这四种算法的载波跟踪环路进行了性能对比。仿真结果表明,基于UPF估计器的载波跟踪环路在高动态、弱信号以及非高斯噪声环境下具有优越的跟踪性能,既可以提高跟踪精度,又解决了非高斯噪声干扰问题。通过模拟实验验证了该方案的有效性。 相似文献
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STC-OFDM系统有效弥补了正交频分复用多址系统中符号间干扰和频率选择性衰落等不足,但存在如何有效抑制因多天线传输产生的相互干扰问题.为此,提出了一种结合信道频率响应恢复和串行干扰消除来抑制干扰的改进算法,该算法在串行干扰消除之前先对导频进行信道频率响应恢复,减小估计对信道频率响应的影响.仿真实验表明,该算法能进一步改善STC-OFDM系统比特误码率并进而抑制相互干扰. 相似文献
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分析了基于分段匹配滤波器(PMF)-FFT实现高动态GPS信号捕获的子相关长度和FFT运算点数对捕获性能的影响,推导出多普勒频移捕获的范围和精度值,针对PMF-FFT捕获的多普勒频移分辨率低的缺点,提出了采用最小二乘法对幅频响应最大峰进行曲线拟合的方法来提高多普勒频率捕获精度的方案,最后对高动态GPS信号的捕获进行了仿真。结果表明:该方法可以很好地实现高动态GPS信号的快速精确捕获,并可以有效地缩短捕获时间和节省硬件资源。 相似文献
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提出一种相干干扰下自适应波束形成方法。该方法同时约束非相干干扰与相干干扰,更好地实现对此两类干扰方向的自适应零陷滤波。采用变换预处理,避免抑制期望信号;恢复噪声特性并采用对角加载技术,增强算法稳健性;采用拉格朗日乘子法得到最优波束形成算法。理论分析与仿真结果表明,保持阵列孔径不变时,该算法提高了输出信干噪比和稳健性。 相似文献
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The V-BLAST system with asynchronous transmission mode first proposed by Shao can achieve full diversity only by using a simple
linear detection scheme under zero forcing (ZF) criterion; therefore it gives a reasonable tradeoff between complexity and
performance. In this paper, we propose two types of successive interference cancellation (SIC) detection schemes for the asynchronous
V-BLAST system, one is characterized by applying M
r
successive interference cancellators before a maximal ratio combiner (where M
t
is the number of receive antennas), and the other has a maximal ratio combiner before a successive interference cancellator.
Since Type I consumes more energy of the previously detected signals to recover a signal, Type II can offer a better performance
and simulations demonstrate its validity. 相似文献
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分析了共形阵机载雷达的杂波非平稳特性,并结合该特性提出了一种非平稳杂波环境下的Doppler补偿方法.不同于传统的线阵天线,共形阵天线的三维空间结构决定了应在四维频域研究其杂波分布.针对这个特点,对共形阵机载雷达的杂波非平稳特性进行了理论分析,揭示了共形阵杂波非平稳现象的本质机理,并得出在任意摆放姿态下共形阵机载雷达均存在杂波非平稳现象这一结论.在此基础上,提出了在四维频域对主杂波进行联合补偿的空时自适应处理(space-time adaptive processing,STAP)方法.经仿真验证,在共形阵机载雷达非平稳杂波环境下,利用本文所提STAP方法的杂波抑制性能显著优于传统的Doppler补偿STAP方法. 相似文献
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This paper considers the problem of scheduling quay cranes which are used at sea port container terminals to load and unload
containers. This problem is studied intensively in a recent stream of research but still lacks a correct treatment of crane
interference constraints. We present a revised optimization model for the scheduling of quay cranes and propose a heuristic
solution procedure. At its core a Branch-and-Bound algorithm is applied for searching a subset of above average quality schedules.
The heuristic takes advantage from efficient criteria for branching and bounding the search with respect to the impact of
crane interference. Although the used techniques are quite standard, the new heuristic produces much better solutions in considerably
shorter run times than all algorithms known from the literature. 相似文献
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Mireille Palpant Cristian Oliva Christian Artigues Philippe Michelon Mohamed Didi Biha 《International Transactions in Operational Research》2008,15(3):307-324
In this paper, a realistic modeling of interferences for frequency assignment in hertzian telecommunication networks is presented. In contrast with traditional interference models based only on binary interference constraints involving two frequencies, this new approach considers the case of cumulative disruptions that are modeled through a unique non‐binary constraint. To deal with these complex constraints, we propose extensions of classical integer linear programming formulations. On a set of realistic instances, we propose hybrid constraint programming and large neighborhood search solution methods to solve minimum interference and minimum span frequency assignment problems. We compare their performances with those of existing heuristics. Finally, we show how the end‐user benefits from using the cumulative model instead of the traditional one. 相似文献
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针对机载分布式雷达地杂波和干扰抑制的问题,提出一种基于小样本协方差重构的机载分布式雷达空时自适应处理(space-time adaptive processing,STAP)方法。该方法根据分布式雷达接收的杂波与干扰具有相关性不同的特点,首先利用小样本估计出各子雷达的杂波空时协方差矩阵和干扰全空域协方差矩阵,然后通过块对角延拓和时域拓展方法得到完整的空时协方差矩阵。所提方法利用全部空域自由度,在有效抑制杂波的同时抑制较多数量的干扰,克服了理想协方差矩阵估计时所面临的独立同分布(independent and identically distributed,i.i.d.)样本严重不足的问题。理论分析和仿真实验验证了所提方法的有效性。 相似文献
17.
FAN JianCun YIN QinYe & WANG WenJie School of Electronic Information Engineering Xi’an Jiaotong University Xi’an China 《中国科学F辑(英文版)》2009,52(6):1067-1074
Focusing on space-time block code (STBC) systems with unknown co-channel interference, an oblique projection-based robust
linear receiver is proposed in this paper. Based on the oblique projection, the desired signal subspace and interference-plus-noise
subspace are first identified from the received signal. Then the matched filter receiver is used to decode the STBC encoded
signals in the desired signal subspace. Simulation results show that the proposed linear receiver obtains significant performance
improvement over conventional Capon-type receivers under finite sample-size situations and in the presence of channel estimation
errors.
Supported partially by the National Natural Science Foundation of China (Grant Nos. 60572046, 60502022, 60772095), and the
National High-Tech Research & Development Program of China (Grant No. 2006AA01Z220) 相似文献
18.
Polarization diverse design of the transmit waveforms based on the property of the target scattering matrix provides better performance than transmitting waveforms with fixed polarizations, especially for mainlobe interference suppression applications. In this work, we propose a radar system combines the advantages of multiple-input–multiple-output (MIMO) systems with the advantages offered by optimally choosing the transmitter polarizations, in order to achieve a better mainlobe interference suppression performance. The polarization diversity is employed in the transmit array, while the receive array adopts 2-D vector sensors to measure the horizontal and vertical components of the received signal. The optimal transmitter polarizations can be obtained by maximizing the output signal-to-interference-plus-noise ratio (SINR) in each coherent processing interval (CPI). In addition, the discrimination method for the target and the interference is studied in this paper, along with the target scattering matrix estimation method. Simulation results demonstrate that interference can be effectively discriminated and suppressed with the radar configuration, and better interference suppression performance is achieved with the optimal transmitter polarizations. 相似文献
19.
This work presents two dual polarized proximity‐fed monostatic patch antennas with improved interport isolation for 2.4 GHz industrial, scientific and medical band same frequency full duplex wireless applications. The presented antennas achieves the high interport decoupling through intrinsic isolation of the polarization diversity in conjunction with a simple single‐tap and two‐taps self‐interference cancellation (SIC) topologies. The polarization diversity isolation is achieved through two perpendicular microstrip feeds for proximity feeding to excite orthogonal polarization mode for transmit (Tx) and receive (Rx) modes. The prototype for proposed antenna with integrated single‐tap and two‐taps SIC circuit is tested to record its interport isolation, impedance bandwidths and gains for both Tx and Rx ports. The implemented antenna with single‐tap SIC circuit demonstrates 10 dB return‐loss bandwidth of ≥100 MHz for both Tx and Rx ports. The measured isolation exceeds 40 dB over the 40 MHz bandwidth. Moreover, the recorded peak isolation is better than 74 dB for implemented antenna prototype. Furthermore, the 40 MHz bandwidth with 40 dB isolation can be tuned with the help of SIC‐tap as demonstrated through the experimental results. The measured gain levels are around 4.6 dBi for both Tx and Rx port. The same antenna structure with integrated two‐taps SIC topology features better than 55 dB isolation within 10 dB return loss bandwidth of 100 MHz. The peak isolation exceeds 97 dB and isolation levels are better than 60 and 80 dB over 50 and 20 MHz bandwidths, respectively, for presented antenna with two‐taps SIC configuration. The compact antenna offers comparatively wider impedance and isolation bandwidth with improved SIC levels compared to previous designs. 相似文献
20.
Space-time adaptive processing (STAP) is an effective method for detecting moving target in airborne/spaceborne radar.However,the detection of fast air moving targets from high speed platform is challenged by the range walk of both the clutter and moving targets.It is well known that keystone formatting can be used to compensate for the range walk of multiple moving targets simultaneously without using the knowledge of the motion parameters.However,in the presence of serious Doppler ambiguity of fast air moving targets,distribution of the clutter will be affected by the keystone formatting matched to the ambiguity number of targets,and as a result the STAP performance will degrade.In this paper,a novel STAP method is proposed for the detection of fast air moving targets from high speed platform,which can deal with the range walk of both clutter and targets.Effectiveness of the new method is verified via simulation examples. 相似文献