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线谱对是一种频域的线性预测参数,在如何对其进行有效地量化方面,人们已经进行了广泛的研究,本文从人的主观感觉出发,将加权均方误差准则应用于线谱对参数的矢量量化中,并用自激励编码方式来检验量化后合成语音质量。实验结果表明,在感沉上8bits线谱对参数的矢量量化与34bits线谱对参数的标量量化几乎产生相同的合成语音质量。 相似文献
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For multiuser multiple-input-multiple-output (MIMO) cognitive radio (CR) networks a four-stage transmiision structure is proposed. In learning stage, the learning-based algorithm with low overhead and high flexibility is exploited to estimate the channel state information (CSI) between primary (PR) terminals and CR terminals. By using channel training in the second stage of CR frame, the channels between CR terminals can be achieved. In the third stage, a multi-criteria user selection scheme is proposed to choose the best user set for service. In data transmission stage, the total capacity maximization problem is solved with the interference constraint of PR terminals. Finally, simulation results show that the multi-criteria user selection scheme, which has the ability of changing the weights of criterions, is more flexible than the other three traditional schemes and achieves a tradeoff between user fairness and system performance. 相似文献
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介绍了一种使用在战术无线通信网络环境的基于稀疏树的战术路由协议.STRP支持单向信道,它采用稀疏树路径生成算法来减少路由更新的数据量并减少网络链路的冗余,采用快速环路消除算法来消除网络拓扑动态变化过程中的环路与计数到无穷问题,采用增量更新来降低路由协议对传输带宽的需求.仿真结果表明,它较为适合战术无线通信网络环境. 相似文献
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The application of low complexity and low order robust regression algorithm in channel estimation with 16QAM over fading channel for DS-CDMA is presented in this paper After initial channel estimation with classical methods, channel gains estimated are filtered by linear or conic regression algorithm within a given regression length Simulation results show that this method offers up to 0,3 dB gain in a DS-CDMA system. The length and order of regression algorithm are two key parameters, which affect the system performance significantly and the optimal values of which depend on the speed of mobile station. It is demonstrated that this improved method can track fading channel accurately and outperforms over classical methods substantially by selecting appropriate parameters of regression algorithm under a certain channel environment. 相似文献
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基于16号数据链和VHF数据链,研究多教据链互连互操作模型.通过利用OPNET仿真工具,在Link16仿真平台上开发网关节点交换模型和VHF数据链终端节点模型和进程模型,实现VHF数据链网络接入、时隙分配管理、业务产生等.通过相关网络仿真属性配置并进行仿真分析,优化网络设计. 相似文献
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针对JTIDS网络中现有时隙分配算法容易导致突发消息时延大问题,在之前提出的随机接入算法基础上,进一步提出适用于JTIDS网络的动态连续时隙分配算法;首先设计基于随机接入的动态连续时隙分配算法,在现有同类算法中计算和通信开销最小,并且具有适应突发消息的功能,增强了网络的抗毁性;接着结合JTIDS消息格式,分析了该算法的传输性能;最后对该算法的通信性能进行了仿真,通过仿真验证理论分析的合理性;分析与仿真结果表明:该算法的传输性能和通信性能均优于现有方案,更适合在JTIDS网络中应用。 相似文献
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认知无线电技术的研究及发展 总被引:1,自引:1,他引:0
认知无线电技术作为软件无线电技术的一个特殊扩展,受到日益广泛的关注.由于该技术能够自动检测无线电环境,调整传输参数,从空间、时间、频率、调制方式等多维度共享无线频谱,可以大幅度提高频谱利用效率.本文首先从认知无线电技术的定义入手,分别讨论了认知无线电的基本概念、功能与实现、标准化的进程.然后介绍了当前应用状况,最后分析了未来的发展及面临的挑战. 相似文献