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根据浮标通信的特点并结合实际运用,给出了一种基于组合天线的接收系统的实现方法。该接收天线由一鞭状天线和一磁感应天线组成,可通过选频电路和高频放大电路实现信号的分集接收。 相似文献
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本文提出了用接收设备的特性和雨接收天线上信号电平的关系来计算双重分集接收制度的方法。接牧设备的特性是用电路输出的行质量和输入信号电平的关系来表示。输入信号电平则用双变数的雷莱(Rayleigh)或然率分布函数来表示。这方法具有充分的普遍性,可以扩展到计算三重分集制度和出现分集衰落观象的频率范围无关。这方法也可简化一下,用来检查非分集接收制度的总效应。 相似文献
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在多模复合制导模式下,被动雷达导引头(PRS)可采用共形天线阵列接收入射信号。共形天线通常为线极化天线,将其摆放在弹体的一周,天线阵列的接收信号将出现极化分集问题。针对该问题,建立了在极化分集条件下共形天线阵列接收信号的数学模型,理论推导极化分集对干涉仪方法测向性能的影响,以及分析干涉仪方法能够正确测向的前提条件,通过计算机仿真实验验证了研究结论的有效性。该文给出了解决共形天线阵列极化分集问题的研究思路。 相似文献
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手机在人们的生活中起着越来越重要的作用,而手机在发送接收信号时性能的好坏。一定成度上取决于射频电路天线部分的设计。介绍了GSM频段手机外置天线的原理和电气特性要求,及依据天线工作原理工厂对手机天线的检验方法。 相似文献
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文章目的在于研究天线的互耦、匹配和极化特性对于基于空分复用的分层结构空时编码多输入多输出(Multiple Input Multiple Output,MIMO)系统误码性能的影响。采用了基于电路网络参数的信号分析模型,精确描述了匹配/未匹配天线阵列的发射、接收特性,接着使用蒙特卡罗分析方法对空分复用MIMO系统的误码性能进行了分析,包括匹配/未匹配线性阵列和极化分集阵列,并且讨论了极化失配特性对误码性能的影响。结果表明,匹配网络的应用能够有效地降低空分复用MIMO系统的误码率;同时极化分集天线的应用能够降低耦合和极化失配的影响,降低系统的误码率。 相似文献
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结合实测数据,分析了短波空间分集的接收信号幅度相关性、相位分布特性以及分集阵列接收的天电噪声相关性,并总结出一些特征。对充分理解空间分集系统的特性以及工程设计有参考意义。 相似文献
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通过选择性最大比合并(SC/MRC)算法,在并行干扰抵消(PIC)技术的基础上,对V-BLAST系统各接收天线的干扰抵消结果按照SC/MRC合并,实现了分集接收.该算法最多可以实现与接收天线数等同的分集增益,而通过选择信道条件较好的几个接收天线进行合并,可以在性能与复杂度之间取得折衷.MRC合并只需与选择合并的天线数线... 相似文献
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The performance of the maximum ratio combining method in correlated rician-fading channels for antenna-diversity signal combining 总被引:1,自引:0,他引:1
Hon Tat Hui 《Antennas and Propagation, IEEE Transactions on》2005,53(3):958-964
The performance of the maximum ratio combining method for the combining of antenna-diversity signals in correlated Rician-fading channels is rigorously studied. The distribution function of the normalized signal-to-noise ratio (SNR) is expanded in terms of a power series and calculated numerically. This power series can easily take into account the signal correlations and antenna gains and can be applied to any number of receiving antennas. An application of the method to dual-antenna diversity systems produces useful distribution curves for the normalized SNR which can be used to find the diversity gain. It is revealed that signal correlation in Rician-fading channels helps to increase the diversity gain rather than to decrease it as in the Rayleigh fading channels. It is also shown that with a relative strong direct signal component, the diversity gain can be much higher than that without a direct signal component. 相似文献
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该文提出了多天线传输系统的非相干天线选择(NON-AS)算法,将广义似然比检验(GLRT)与天线选择结合应用于U码传输系统,天线选择和信号检测无需信道状态信息。与相干检测的天线选择相比,NON-AS算法不需要估计信道,大大降低了系统复杂性。该文只考虑了接收天线选择,天线选择的准则是基于每个天线接收到的信号向量F-2范数。仿真结果表明,在高信噪比条件下,选择有最大范数的接收天线子集,系统能实现和使用全部接收天线的U码传输系统渐近相同的分集增益。 相似文献
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在无线通信系统中,不同场景下有不同的传播模型。为了研究发射分集技术对抗多径效应的性能,文中总结了无线通讯系统中室外场景下的传播模型。针对传统的Okumura-Hata传播模型来研究不同环境下发射信号的功率损耗,在接收端计算各信号副本的接收功率,通过与预设的接收功率门限作比较,得出每个信号副本以及各副本等增益合并后的信号可用性,从而研究发射分集对于信号可用性的提升作用。仿真结果表明,分集技术能明显提升接收机接收信号的可用性。 相似文献
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A full frequency diversity COFDM (FD-COFDM) scheme based on sub-channel multiplexing is proposed to improve the performance of COFDM without sacrificing spectral efficiency. Since the channel suffers the frequency selective fading, the received signal contains strong inter-symbol interference (ISI). To obtain the diversity- and code-gains, an iterative receiving algorithm is presented. By jointly using diversity combining, interference cancelation and soft decoding, the proposed iterative receiving algorithm properly decodes the information bits in the strong ISI environment. Consequently, all the subcarriers of FD-COFDM participate in diversity so that the system can achieve full frequency diversity in most practical channels. The new receiving algorithm is relatively simple compared to the maximum likelihood estimation algorithm, and is therefore a better alternative to balance the algorithm complexity and system performance. 相似文献
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《Vehicular Technology, IEEE Transactions on》1987,36(2):63-70
A new receiver diversity scheme for differential detection of minimum shift keying (MSK) is proposed. The signal from each receiving branch is translated to a different IF frequency. The IF signals are summed and then detected by a common differential detector. The diversity scheme does not need phase adjusters, signal quality measurement circuits or a switching controller; moreover the error rate performance is equivalent to that of postdetection equal gain combining diversity, which needs plural complete receiving systems. Theoretical analysis and computer simulation results show that the diversity gain of the proposed scheme is about 13 dB at a 10-3error rate under Rayleigh fading and 5 dB under Rician fading when the signal-to-interference power ratio is 10 dB. The static error rate performance improvement was confirmed by experimental test results. Simulation results with data from mobile propagation studies are also shown. Even in heavily shadowed cases, the probability that fading attenuation is less than 17 dB is improved from 80 to 99 percent, and a 7 to 13 dB improvement in margin requirement for 99 percent of time operation is achieved. 相似文献