中大口径舰炮“同时弹着”打击海面快速小目标方法

从近几年的海上安全形势来看,机动性好、体积较小的自杀式小艇已成为除反舰导弹外水面舰艇面临的最大杀手,如何实现对海面快速小目标的拦截和打击,是各国海军普遍面临的难题。因此,提出了中大口径舰炮“同时弹着”打击海面快速小目标的射击新方法,并建立了中大口径舰炮“同时弹着”模型,验证了中大口径舰炮2发同时弹着的可行性。同时,对中大口径舰炮“同时弹着”的误差、射击效力和适用距离等关键问题开展了研究。最后,结合实际战术应用,给出了中大口径舰炮基于梯次射的“同时弹着”射击方法,并通过仿真验证了该方法对打击海面快速小目标的有效性。

快速收敛仿射投影算法在稀疏水声信道的应用

本文提出了一种新的快速收敛比例仿射投影算法,并将算法应用于稀疏多径水声信道均衡。该算法首先在改进比例仿射投影算法(improved proportional affine projection algorithm,IPAPA)的基础上引入变步长算法,提高算法的收敛速度;并在此新算法的基础上通过引入判决反馈结构,进一步改善算法收敛后的稳态误差。在两种典型的稀疏多径水声信道环境下,通过正交相移键控和16进制的正交幅度调制方式对算法的收敛性能进行了仿真。仿真分析了变步长算法中的3个参数γ,η,ζ的取值范围对算法收敛性能的影响,比较了变步长比例投影算法与最小均方类算法、递归最小均方(recursive least square,RLS)算法性能以及基于判决反馈均衡器(decision feedback equalization,DFE)结构的各算法的收敛性能。仿真结果显示,新算法的收敛性能相比IPAPA算法的收敛性能更好,与RLS算法性能相当,且基于DFE结构的各算法的收敛趋势亦相同。

Power optimization algorithm for OFDM underwater acoustic communication using adaptive channel estimation

An adaptive channel estimation algorithm for the channel length is proposed to construct a channel estimation model suitable for orthogonal frequency division multiplexing(OFDM)underwater acoustic communication signals for the dependence of traditional channel estimation algorithms on channel length information.This algorithm can be adopted to evaluate channel estimation quality in real time and to adaptively adjust the channel length of the channel estimation algorithm according to the evaluation result,which satisfies the need of accurate estimation of unknown underwater acoustic channels and communication application;based on the study on the relationship between the OFDM communication bit error rate and the subcarrier signal to noise ratio,a self-adjusting optimization scheme for OFDM subcarrier transmitting power is proposed,which realizes underwater communication with the low bit error rate through higher energy efficiency.The validity of the research content is verified through simulation and field experiments.