共查询到18条相似文献，搜索用时 750 毫秒
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采用多入多出(MIMO)技术可以提高信道容量和信道可靠性,降低误码率.正交频分复用(OFDM)是一种特殊的多载波传输方案,各子载波在整个符号周期上正交,各子载波信号子频谱可以互相重叠,提高频带利用率.MIMO-OFDM技术是OFDM与MIMO技术结合形成的一种新技术,该技术是在OFDM传输系统中采用阵列天线实现空间分集,提高了信号质量.本文全面介绍了MIMO技术和OFDM技术及两者的结合,分析实现MIMO-OFDM技术的框架. 相似文献
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多输入输出（MIMO）技术和正交频分复用（0FDM）技术各有独特的优势和缺陷。MIMO技术可以大幅度提高无线通信系统的容量,但是抗频率选择性信道能力不强;OFDM技术利用正交子载波抗频率选择性信道,提高了频率利用率,易受频率偏差的影响,存在较高的峰值平均功率比。MIMO与OFDM技术结合构成的MIMO—OFDM系统既可以达到很高的传输效率,又有很强的可靠性,具有很大的研究空间和实用前景。 相似文献
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正交频分复用(OFDM)技术支持高速数据传输,具有抗多径干扰以及频谱利用率高等优点。多输入多输出天线(MIMO)技术可以提高无线移动通信系统的性能和容量,这二者的结合成为B3G移动通信系统的核心技术之一。对MIMO-OFDM系统中不同信道状态信息条件下的自适应调制编码进行性能的仿真和比较,仿真结果表明信噪比高时,采用高阶调制可以极大地提高系统吞吐量;基于奇异值分解的自适应技术对多普勒扩展比较敏感。 相似文献
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OFDM技术的基本思想是将所要传输的数据流分解成多个比特流,每个子数据流具有更低的传输比特速率,并且用这些数据流去并行调制多个载波。正交频分复用是一种特殊的多载波传输方案。OFDM应用离散傅里叶变换（DFT）和其逆变换（IDFT）方法解决了产生多个互相正交的子载波和从子载波中恢复原信号的问题。 相似文献
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OFDM系统中的关键技术 总被引：3，自引：0，他引：3
随着通信技术的不断成熟和发展,正交频分复用(OFDM)作为一种具有高频带利用率、可以有效对抗信号波形间干扰的高速传输技术,引起了广泛关注。OFDM系统各个子载波之间正交,允许子信道的频谱相互重叠,最大限度地利用了频谱资源。本文就OFDM系统中的关键技术进行了探讨。 相似文献
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正交频分复用（OFDM）技术支持高速数据传输，具有抗多径干扰以及频谱利用率高等优点。多输入多输出天线（MIMO）技术可以提高无线移动通信系统的性能和容量，这二者的结合成为B3G移动通信系统的核心技术之一。对MIMO—OFDM系统中不同信道状态信息条件下的自适应调制编码进行性能的仿真和比较，仿真结果表明信噪比高时，采用高阶调制可以极大地提高系统吞吐量；基于奇异值分解的自适应技术对多普勒扩展比较敏感。 相似文献
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《Journal of The Franklin Institute》2023,360(10):6804-6826
In this research, a hybrid adaptive bionic fuzzy control strategy is developed for a class of complicated nonlinear multiple-input-multiple-output (MIMO) systems with dead-zone input. The first component of the bionic adaptive controller is a general phrase for tunning system parameters depending on the present state, and the second component is a trend-based compensation for adjusting the system parameters. This technique makes the system more intelligent and boosts its anti-interference capabilities. The stability and convergence are analyzed using the Lyapunov synthetic method, and thus the parameter restrictions of the MIMO system are provided. Finally, the strong anti-interference of the system is verified by the simulations. 相似文献
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In this paper, the consensus problem of multi-agent systems with general linear dynamics is studied. Motivated by the MIMO communication technique, a general framework is considered in which different state variables are exchanged in different independent interaction topologies. This novel framework could improve the control system design flexibility and potentially improve the system performance. Fully distributed consensus control laws are proposed and analyzed for the settings of fixed and switching multiple topologies. The control law can be applied using only local information. And the control gain can be designed depending on the dynamics of the individual agent. By transforming the overall multi-agent systems into cascade systems, necessary and sufficient conditions are provided to guarantee the consensus of the overall systems under fixed and switching state variable dependent topologies, respectively. Two simulation examples are provided to illustrate the effectiveness of the proposed theoretical results. 相似文献
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正交频分复用(OFDM)作为一种多载波数字通信方案,是第四代移动通信的核心技术。本文介绍了OFDM基本原理,建立了其通信系统模型,并利用Matlab实现了整个系统的动态仿真。仿真结果表明,该系统能很好地反映OFDM的性能特点,同时验证了该仿真方法的正确性和可行性。 相似文献
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In this paper, an intelligent self-repairing control scheme is proposed for a class of nonlinear MIMO system. A direct self-repairing controller of a nonlinear SISO system is firstly designed, and then the control scheme is promoted to a nonlinear MIMO system. The error signals are replaced by the state variables to deal with the high derivate problems of the desired signals and a nonlinear regulating function is brought in to improve the performances of the sliding mode. The self-repairing controller is made up of four parts: the nonlinear regulator, the equal controller, the compensator I and the compensator II. The control method is applied to a helicopter flight control system with loss-in-effectiveness faults. Some simulation results illustrate the effectiveness and feasibility of the proposed control scheme in the paper. 相似文献
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