水面舰艇编队系统对空作战能力研究

根据现代防空系统的特点,提出了水面舰艇编队区域防空系统效能评价的指标体系,分析了指标的相关因素,运用指数法建立了防空系统效能分指标(预警探测能力指数、拦截打击能力指数、指挥控制能力指数、电子战能力指数)以及效能综合指标的求取模型.     

Combustion characteristic and aging behavior of bimetal thermite powders

Nanothermites have been employed as fuel additives in energetic formulations due to their higher en-ergy density over CHNO energetics. Nevertheless, sintering and degradation of nanoparticles signifi-cantly limit the practical use of nanothermites. In this work, combustion characteristic and aging behavior of aluminum/iron oxide (Al/Fe2O3) nanothermite mixtures were investigated in the presence of micron-scale nickel aimed to produce bimetal thermite powders. The results showed that the alumina content in the combustion residue increased from 88.3％ for Al/Fe2O3 nanothermite to 96.5％ for the nanothermite mixture containing 20 wt％nickel. Finer particle sizes of combustion residue were obtained for the nanothermite mixtures containing nickel, indicative of the reduced agglomeration. Both results suggested a more complete combustion in the bimetal thermite powders. Aging behavior of the nano-thermite mixture was also assessed by measuring the heat of combustion of the mixture before and after aging process. The reduction in heat of combustion of nanothermite mixtures containing nickel was less severe as compared to a significant decrease for the nanothermite mixture without nickel, indicating better aging resistance of the bimetal thermite powders.     

A new energy efficient management approach for wireless sensor networks in target tracking

This paper mainly studied the problem of energy conserving in wireless sensor networks for target tracking in defensing combats. Firstly, the structures of wireless sensor nodes and networks were illustrated; Secondly, the analysis of existing energy consuming in the sensing layer and its calculation method were provided to build the energy conserving objective function; What's more, the other two indicators in target tracking, including target detection probability and tracking accuracy, were combined to be regarded as the constraints of the energy conserving objective function. Fourthly, the three energy conserving approaches, containing optimizing the management scheme, prolonging the time interval between two adjacent observations, and transmitting the observations selectively, were introduced; In addition, the improved lion algorithm combined with the Logistic chaos sequence was proposed to obtain sensor management schemes. Finally, simulations had been made to prove the effectiveness of the proposed methods and algorithm.     

多制式调制模块的原理与设计

分析了多制式调制的原理 ,提出并实现了一种基于PCI总线的多制式调制模块的设计方案。它采用正交调制与数字上变频方法 ,可以生成多种中频调制信号。它的另一个特点是将基带处理单元用PCI总线隔离开来 ,可以结合通用计算机或商用DSP处理模块 ,构成一结构灵活而又具有实时处理能力的多制式调制系统。     

一种攻击机机群作战效能的分析方法

以平均动态学理论为基础,提出了攻击机机群在整个战斗飞行过程中的作战效能评估的基本原理,建立了战效评估的顶层分析数学模型,导出了效能指标与对地攻击靶场效能指标、国土防空系统突防效能指标、要地防空系统突防效能指标间的关系式及完成作战任务集所需飞机架数、被击毁的总架数、总战斗飞行架次数、武器总消耗量的计算式,为评价攻击机机群在整个战斗飞行过程中的作战效能奠定理论基础     

武装直升机火箭武器对地攻击方式效能评估

根据某型武装直升机机载火箭武器的四种对地攻击方式,建立了该型直升机实战中将遭遇的作战条件的战场模型。采用层次分析法,建立了确定各作战条件模块加权系数的判断矩阵并计算了加权系数;结合各种对地攻击方式和该型直升机火箭武器系统的特点,确定了各攻击方式下各模块的效能系数。在加权系数和效能系数的基础上,计算了各作战条件下四种对地攻击方式各自的作战效能,得出一个当前作战条件下的最佳攻击方式提供给飞行员。为飞行员实施对地攻击提供了科学依据     

大规模 MIMO系统中用户分层变长时隙分配方法研究

大规模MIMO系统时分双工模式中分配的物理时隙长度是固定的,不能根据不同时长的信道相干时间灵活地调整长度,二者长度的不匹配导致部分时频资源的浪费,因此系统的总体容量不能达到最优。针对此问题本文提出一种用户分层变长时隙分配方法,即根据不同终端的移动性对终端进行分层,并为不同层中的移动终端灵活地分配不同时长的物理时隙,使物理时隙长度与移动终端所对应信道的相干时长相匹配,从而减少时频资源的浪费,提高了资源利用率。同时,避免了低速移动终端过频繁的信道估计,降低了信道训练序列开销,使系统的总体数据容量得到很大的提升。实验仿真结果验证了本文所提方法的有效性。     

基于群体协同的驱护编队中近程防空的系统效能

针对中近程反导的具体要求,分析了典型的驱护编队反导模式下编群队形特点,研究了指挥舰与护卫舰的队形关联性,探讨了基于信息化作战模式的抗饱和攻击能力,建立了基于多目标优化的最保守与最乐观情况下的抗饱和攻击模型,得到舰艇编队协同防空的系统效能,对驱护编队防空反导指挥决策具有很强的参考价值。     

基于谱分析的卫星通信调制识别算法

通过分析典型卫星通信信号功率谱、平方谱、四次方谱以及包络平方谱特性,针对卫星通信随参信道造成信号噪声谱均值与方差随频率变化这一问题,采用最小二乘法对信号谱图进行预处理,定义偏离比作为单频分量检测值,在无任何先验知识条件下提取一组鲁棒性强的特征参数,实现信号自动调制识别。实验证明,改进后的算法复杂度较低、过程简单易实现,所提取参数对数字信号的调制指数与滚降系数不敏感,具有较好的可分性与稳健性,并同样适用于随参信道的信号调制识别,具有一定的实用意义。     

基于FrFT的差分跳频通信LFM干扰抑制算法

针对差分跳频通信系统抗LFM干扰能力不足的问题,利用差分跳频信号和LFM干扰信号调频斜率参数的不同,通过估计采样信号中LFM干扰信号的调频斜率K和旋转阶次α参数,结合分段、参数估计和均值处理提高估计精度,进一步在采样信号的分数阶时频域二维参数平面(α,μ)中利用LFM干扰信号频带外的平面均值替代LFM信号成分,实现对差分跳频通信中LFM干扰信号的抑制。仿真结果表明,该算法可有效抑制差分跳频信号中LFM干扰信号,提高信噪比约11 d B。