基于WINC的自适应主分量提取的盲多用户检测算法

本文提出了一种新的基于子空间追踪的盲多用户检测算法。首先分析了基于加权信息准则（WINC）的自适应主分量提取（APEX）方法,然后将AIC准则与之结合使其能用于主分量个数未知的情况,最后还增加了一次正交化操作以加快收敛速度。仿真结果显示,本文提出的算法在用户数目较多的情况下比经典的OPAST算法有着更好的性能。      

Optical ISL tracking considerations in meeting ISDN requirements

Burst errors in an optical intersatellite link (ISL) are short term (of the order of a millisecond) degradations of the link due to antenna mistracking. These errors degrade the average bit error rate (BER), decrease coding gain, complicate calculations of tracking accuracy, and give rise to concern about the quality of the link for carrying digital signals. After reviewing previous work on these topics, the digital performance of the link is examined in terms of how these considerations affect the ability of an optical ISL to meet ISDN (Integrated Services Digital Network) criteria for an ISL. A link with on-board regeneration is assumed. Since no allocation has yet been made for an ISL, an allocation of 25 per cent of the degradation permitted for the satellite link by CCITT Rec. G.821 and CCIR Rec. 614 is assumed here. It is found (1) that if the requirement derived from Rec. 614 is met, the requirements derived from Rec. G.821 are also met and (2) that an optical ISL should have little difficulty in meeting these requirements.     

极值步进跟踪在车载移动卫星通信中的应用

本文介绍了记忆极值跟踪的原理、车载移动卫星通信跟踪系统的组成和软件设计以及对实际遇到的问题的处理。     

Renewal-theoretic considerations in evaluation of forecast monitoring schemes

To evaluate the performance of a scheme for monitoring forecasts that are generated by exponential smoothing, forecasters have traditionally used a simulation-based estimator of some characteristic of the associated run-length distribution. The most frequently cited performance measures are the average run length and the probability that the run length does not exceed a user-specified cut-off point. However, there is disagreement about the definition of run length that is appropriate in the context of forecasting. In this paper we use fundamental results from renewal theory to establish the precise relationships between conflicting formulations both of the average run length and of the probability density function for the run length. More generally we derive the asymptotic mean and the asymptotic distribution function of the forward recurrence time for both ordinary and delayed renewal processes whose interoccurrence distributions are arithmetic with a given span. We discuss the practical significance of these results in the context of forecasting. Our findings bear directly on the way in which simulation experiments should be designed and executed to compare alternative forecast monitoring schemes.     

无人车集群协同围捕发展现状分析

无人车集群具有成本低、安全性好、自主程度高等优点,已成为无人驾驶领域的研究热点。基于无人车集群,研究人员提出多种不同协同策略以完成各类任务,其中协同围捕作为重要的应用方向,无论是在军用还是民用领域都受到了广泛关注。针对此问题,该文首先基于无人车集群的相关应用和架构,对协同围捕的策略机理进行了系统分析,并将协同围捕策略划分为搜索、追踪和围堵3个子模式。然后,从博弈论、概率分析和机器学习等角度梳理了协同围捕的关键方法,并对这些算法的优缺点进行了比较。最后,对未来研究提出了意见建议,为进一步提高无人车集群协同围捕的效率和性能提供参考和思路。     

Signature driven multiple target tracking

Tracking multiple maneuvering targets remains a challenge due to the existence of clutter and the disturbance of spurious targets. Traditional tracking algorithms treat target measurements as points which results in the loss of information. We have propose a Signature Driven multiple-target Tracking (SDT) method which uses target signature in spectral, spatial and temporary spaces as well as the Markov property of target motion, and the data association process in SDT is very effective. The experimental results have shown its outstanding performance.     

角度信息辅助的集中式多传感器多假设跟踪算法

对于密集杂波环境中的多目标跟踪,传统集中式多传感器多假设跟踪(CMS-MHT)算法在每一时刻的航迹-量测关联假设数量大大增加,导致数据关联不确定性增大,以至很难由常规航迹得分给出正确关联,表现为高的漏情率以及航迹分裂现象。基于传感器测量误差较小时虚警与目标量测的空间分布特点,针对多个相同类型传感器进行目标跟踪,该文提出一种角度信息辅助的CMS-MHT算法,设计了新的角度信息辅助的航迹得分计算方法,可以降低航迹-量测关联的不确定性,从而得到比传统CMS-MHT更优的关联假设。仿真实验结果表明,在密集杂波环境中,该算法能有效降低漏情率,并有更好的航迹完整性。     

LEO卫星接入TDRSS的可行性分析与仿真

该文讨论了使用固定天线和中低发射功率的LEO卫星接入到跟踪与数据中继卫星系统(TDRSS),并通过跟踪与数据中继卫星(TDRS)来实现空-地数据传输的可行性。文中给出了LEO卫星与TDRS进行通信需满足的前提条件,提出了通过计算机仿真来计算LEO卫星与TDRS全天通信时间和通信业务量的一般思路和具体实现方法,为论证具有固定天线的LEO卫星接入TDRSS的可行性提供了依据。     

Unscented粒子滤波器及其在纯方位跟踪中的应用

为处理纯方位跟踪(BOT)中的非线性问题,提出了一种Unscented粒子滤波(UPF)跟踪方法。在使用Unscented变换的基础上,利用UPF来加入最新的观测量并产生非线性粒子滤波(PF)的建议分布。结合纯方位跟踪模型,推导了UPF应用的具体算法步骤,使用匀速运动和机动目标两个BOT仿真实例,与其它滤波器进行了仿真对比,分析了跟踪性能和误差。仿真结果表明,对于纯方位跟踪问题,UPF不仅解决了扩展卡尔曼滤波器的线性化损失难题,而且与PF等粒子滤波器相比,具有更高的跟踪精度。     

基于融合策略自适应的多线索跟踪方法

基于多线索融合的跟踪是跟踪领域近年来的研究热点之一,该文结合两种常用的线索融合方式：乘性融合及加权和融合,提出一种融合策略自适应的鲁棒跟踪方法。该方法使用粒子滤波技术,统计样本的二阶中心矩并求Frobenius范数以表征线索的受噪声污染程度,最后适时切换两种融合策略。实践证明,新的融合策略比传统单一的融合方式更鲁棒。