共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
共形天线的安装和测量以及载体平台表面的变形和振动均会引起阵元位置误差,严重影响
共形天线的测向性能。通过设置4个方位未知的精确校正的辅助阵元,实现了共形天线大尺度三维
的阵元位置误差校正。给出了阵元位置误差条件下共形天线导向矢量的方位依赖的幅相误差等效
表示模型;基于子空间原理得到等效的方位依赖的幅相误差估计,进而得到共形天线阵元的三维位
置误差估计。该方法可以实现共形天线校正信源来波方位和阵元三维位置误差的联合但“去耦”估
计。计算机仿真结果验证了共形天线阵元位置误差校正的辅助阵元法的有效性 相似文献
3.
4.
有源相控阵天线的近场校准 总被引:1,自引:0,他引:1
为实现对相控阵天线的校准,降低幅相误差和阵元失效对天线性能的影响,提出了一种考虑互耦效应的近场校准方法。在利用近场扫描法完成逐一通道校准的基础上,使用旋转矢量法进行二次校准。在应用旋转矢量法( REV)时,为使被测信号的变化明显,将大规模相控阵天线分为中间、边缘区域进行分区校准。通过二次校准可判定阵元是否失效,提高相控阵天线的幅相一致性;通过分区校准减小阵元间互耦的影响,缩短校准时间。仿真结果表明:此方法用于大型相控阵的校准具有较高的准确性,可改善校准结果。 相似文献
5.
6.
均匀圆阵中的波束合成技术 总被引:1,自引:0,他引:1
针对均匀圆阵天线的阵列布局,建立了天线阵列对信号的接收模型,提出了一种实用的直接加权波束合成技术。在分析了系统误差来源并修正了系统误差校准模型的基础上,给出了详细的波束合成理论推导。结合实际系统给出了工程上的具体实现,并运用正交校准技术对由设备通路引起的系统误差进行校准。对该算法进行计算机仿真验证其可行性,并与实际效果图进行比较,指出算法的优点和不足。所给出的理论和方法都通过了工程检验,具有一定的实用性。 相似文献
7.
This paper proposes a single‐RF MIMO receiver that adopts a beam‐switching antenna (BSA) instead of a conventional array antenna. The beauty of the proposed single‐RF MIMO receiver with BSA is that it can be deployed in a very small physical space while achieving a full spatial multiplexing gain. Our analysis has revealed that the use of a BSA inevitably results in the spectrum spreading effect at the RF output, which in turn causes an SNR decrease and adjacent channel interference (ACI). Two novel receiver techniques are proposed to mitigate the issues of redundant sub‐band suppression and ACI avoidance. Numerical analysis results verify the performance improvement from the proposed receiver techniques. 相似文献
8.
多馈源空间馈电阵列误差校正 总被引:5,自引:1,他引:4
空间馈电阵列是相控雷达天线的一个重要发展方向,阵列误差校正技术则是大多数阵列信号处理方法在工程实现中的重要保障条件,本文针对一种多馈源空间馈电阵列模型,利用主阵面上T/R模块中的移相器,提出了一种阵列误差校正方法,计算机仿真结果证明了其有效性。 相似文献
9.
10.
The incorporation of directional sensitivity, provided by so-called adaptive antennas is useful in suppressing interfering signals that arise from spatially distinct mobile sources. The problem is that in a cellular radio environment where multipath exists, the standard adaptive antenna using reference signals may not properly lock on the desired signal. This is because the signal correlation matrix processed by the antenna may then be close to singular and standard algorithms fail. Also, most standard algorithms need to cooperate with the receiver for the spatial discrimination of signals. A smart antenna utilizing a blind algorithm is of interest since the antenna may not need to get any feedback from a receiver for the adjustment of weight coefficient for spatial processing and can stand alone to be plugged into any kind of receiver structure.In this paper, we address the convergence property of a Constant Modulus Algorithm which is a blind algorithm and, if employed, can provide no need for an antenna to cooperate with a receiver attached. By identifying a relationship between the weight coefficients and output signal amplitude, we also evaluate the performance of such a stand-alone antenna plus a CDMA matched filter reception. Our results show that for a three element CM array, the BER of a desired user with the other interfering users is much better than a conventional correlation receiver for a single user case since the array suppresses interferences and achieves array gain in SNR. 相似文献
11.
12.
13.
14.
This paper presents a general‐purpose design scheme of a filter bank (FB)–based radio frequency (RF) transceiver that operates across the entire ultra‐high frequency (UHF) TV band from 470 MHz to 698 MHz and complies with the TV white space (TVWS) regulatory requirements. To this end, an intermediate frequency (IF) band‐pass filter (BPF) with a sharp skirt characteristic is considered as a solution for handling the incoming signals from a baseband modem. Specifically, an FB‐based BPF structure with four ceramic resonator filters that effectively rejects unwanted signals is proposed to extract a desired signal in the TV band. Achievable data rates of a cognitive radio system (CRS) employing the proposed FB‐based RF transceiver at the application layer are investigated in both wired and wireless environments. The service coverage of the CRS network is measured according to several modulation and coding schemes (MCSs) of the CRS. The results show that the coverage of a wireless network in a nearly open area can be extended by more than 9.3 km in the TVWS. Experimental results also confirm that the proposed FB‐based RF transceiver is adequate for utilization in TVWS applications. 相似文献
15.
16.
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
17.
针对欺骗式干扰影响飞行器卫星导航信号后引起的定位测姿错误问题,提出了一种适用于飞行器导航的基于阵列天线的欺骗式干扰检测和消除方法.使用接收阵列天线的载波相位双差测量值作为干扰检测依据,通过载波相位单差测量方程求出干扰信号的方向矢量,给出了提高干扰方向测量精度的方法,并使用其正交向量在干扰方向形成零陷,同时通过调整波束指向,在待测信号方向形成阵列增益,以达到抗干扰和增强导航信号的目的.使用这种方法可以对导航信号中的欺骗式干扰信号进行有效的识别和消除,适用于复杂环境下的飞行器导航. 相似文献
18.
Ning Xie Yuanping Zhou Li Zhang Gongbin Qian Hui Wang Xia Li 《Wireless Communications and Mobile Computing》2009,9(2):239-249
Design of a nonlinear adaptive antenna array receiver is a challenging task in wireless communications due to the limited number of antenna elements and the presence of correlated signals, which directly affect the performance of an antenna array. More importantly, a conventional nonlinear array receiver is often associated with a high computational complexity that undermines its applicability in practice. In this paper, we present a new approach to adaptive beamforming receiver that provides superior performance in antenna array overloading and in the presence of correlated signals with a low complexity. In particular, the proposed receiver requires a small data‐record size to estimate the beamformer weights, which is beneficial in applications with fast fading channels. Simulation examples illustrate the performance improvement of the proposed array receiver when it is compared to the conventional beamformers. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
19.
针对数字阵列天线的发展需求,介绍了用快速傅里叶变换法、数字混频低通滤波法、多相滤波正交下变频法等3种数字接收机通道内信号的幅度、相位计算方法,给出了数字阵天线接收通道的内校准法和外校准法,以及校准后的天线方向图计算公式,并用实验结果检验了上述方法的有效性。 相似文献
20.
介绍了一般测量装备的标校方法及步骤,对基于阵列天线测量装备的标校方法做了进一步论述。利用此标校方法,解决了基于阵列天线的测量装备测量数据处理的精确度问题,通过测量值与提供的真值比较,结果表明该标校方法合理实用并且精度较高,提高了装备保障水平,该研究成果可为靶场其他测量装备的标校提供借鉴。 相似文献