基于主动式时间反转镜的声呐目标强度测量研究

为提高目标强度测量过程中的抗噪声、混响以及浅海多途干扰性能,从军标文件中的目标强度测量方法以及主动式时间反转镜的基本原理出发,经过研究和推演,发现可将基于单阵元的主动式时间反转镜与相关器结合应用于目标强度测量过程,提出了一种新的目标强度测量方法。该方法利用了主动式时间反转镜的抗多途特性,使得测量具有抗多途的性能;利用噪声与信号的不相关特性,算法结合相关器起到了很好的抗随机噪声效果;混响中的体积混响是随机的,算法具有抗体积混响的性能。论文分别从理论仿真和水池实验验证了算法的有效性和正确性。     

一种新颖的有制冷直调激光器偏置电路设计

提出了单电源供电的有制冷直调激光器设计方案,解决了APC反馈控制的重复设计问题;在简化电路,降低成本的同时,保证了激光器温度和输出功率的稳定性.     

基于透明转发器的卫星通信抗干扰技术及仿真系统

首先分析了透明转发器特点，研究了其在各种限幅条件下的抗干扰性能，然后全面分析了基于透明转发器的各种抗干扰技术，研究了各种抗干扰技术的特点及抗干扰能力，最后，提出了用于透明转发器抗干扰研究的仿真系统总体结构，并给出了其抗干扰性能评估方法。为透明转发器抗干扰研究提供了技术基础并指明 了方向，对商业卫星通信系统用于军事通信具有参考价值。     

基于ZigBee技术的无线射频识别系统设计

将ZigBee技术与RFID技术相结合,构建一套基于ZigBee技术的无线射频识别系统.系统具有识别距离长,不需要进行方向配置,灵活性和可扩展性好;数据信息的可靠性、抗干扰性和保密性高;技术相对简单、成本低、时延小、存储容量大等特点.     

一种惯性/水声单应答器距离组合导航方法

惯性/水声单应答器距离组合导航方法为自主水下航行器(AUV)校准提供了一种新途径。针对惯性/水声单应答器距离组合导航系统,建立了AUV三维空间运动学模型,对单应答器距离变换位置非线性系统采用李导数方法进行了可观测性分析,设置了合理的载体航行轨迹,位置组合导航算法中采取了延时状态滤波方式实现了量测信息的同步更新。湖上实验表明,采用单应答器距离组合导航方法后,明显地抑制了INS/DVL导航误差的发散趋势,最大定位误差减小幅度约为19.2%,初步验证了惯性/水声单应答器距离组合导航方案的有效性,为解决AUV导航设备水下校准提供了可能。     

上行干扰条件下软限幅转发器中滤波器带宽的影响

研究了在上行干扰条件下软限幅卫星转发器中滤波器带宽对系统性能的影响。分别给出了信号、干扰和噪声的合成包络与相位的联合概率密度函数的计算方法，并通过对限幅器输出信号分别对于合成包络和相位平均，计算输出信号中包含的周期信号和非周期信号功率，从而计算小信号的功率压缩情况。通过应用专用仿真软件ACOLADE，对在上行干扰条件下转发器中滤波器带宽对小信号压缩的影响进行了仿真，给出了小信号压缩相对于滤波器带宽的仿真曲线。     

Variation of satellite transponder delay

For precise orbit determination of geosynchronous earth orbit(GEO)satellites using transfer ranging observations,it is generally assumed that the variation of the satellite transponder delay is very small and that it can be solved as a constant parameter together with satellite orbit parameters.However,this assumption is too general and it reduces the accuracy of orbit determination for GEO satellites.To study and analyse the impact of the satellite transponder delay on GEO satellites orbit determination,two schemes were proposed.First,the satellite transponder delay was eliminated by forming single-difference observations between two ground stations;second,the satellite transponder delay was described as a constant parameter.The preliminary results demonstrate a difference of about1–2 m between the two schemes when used for precise orbit determination of GEO satellites.By fixing the GEO satellite orbit and other relevant parameters estimated by single-difference model,we inversed the instantaneous transponder delay from non-difference observation.It was found that the satellite transponder delay has a distinct diurnal variation,with an amplitude of 3–4 m.The findings of this paper are helpful in establishing an accurate model of satellite transponder delay and in improving the accuracy of GEO satellites orbit determinations and predictions.     

一种具有新型解调电路和安全功能的超高频RFID 标签芯片

设计一种具有新型解调电路和安全功能的超高频RFID标签芯片。该解调电路不需要单独的包络检测电路, 而是利用标签芯片已有的整流器的第一级作为包络检测电路。同时还设计了一种特殊的均值检测电路, 输出电压和包络信号之间有很大的电压差, 使得比较器的设计更加容易。受标签和读写器距离的变化影响, 包络信号的直流电压在很大范围内变化, 因此还设计了具有轨到轨共模输入范围的比较器。为了保证标签和读写器之间通信的安全, 在数字基带处理器中集成了128位的高级加密标准算法(AES)。整个标签芯片 采用0.18μm工艺实现, 芯片面积为880μm×950μm。测试结果表明, 标签芯片可以解调出的射频输入信号最小幅度为100 mV, 最大的数据率为160 kb/s。     

Design and development of a new architecture of sliceable bandwidth variable transponder

In this paper we propose a new sliceable bandwidth variable transponder (SBVT) architecture with the separate analysis on the transmitter and receiver section. In transmission section we propose a distance module (DM) which is a programmable module. It divides a data stream/main stream (which employs a super-channel) into sub-stream and assigned modulation technique to each sub-stream based on their light path distance detailing the concept of sub-channel. In this paper, we have also proposed an algorithm for the distance module. Next we propose a modulation and transmission module (M&TM), where, planar light wave circuit (PLC) is used for enabling three modulation techniques (PM-16QAM, PM-QPSK and PM-BPSK). Finally, we propose the receiving section, which is designed to support three modulation techniques. It consists of two demodulator circuits, one for PM-16QAM/PM-QPSK and the other for PM-BPSK. In this proposed work, we focus on the multi-mode interference (MMI) devices (MMI coupler and MMI splitter) because of their photonic integration technology which is necessary for the implementation of SBVT. Lastly, we propose an elastic optical node architecture which removes the limitations of previously discussed node architecture for long distance communication.     

卫星多电平SCPC系统的交调分析和计算

卫星通信中准确而方便地计算交调干扰对颖分多址(FDMA)有巨大的实际意义。特别对一个转发器中有很多载波的单路单载波系统(SCPC)来说,这种计算显得更为重要。本文利用贝塞尔级数法对多电平SCPC系统的交调作了分析,并在DPS-8机(Fortran语言)和王安MVP-2200机(BASIC语言)上进行了实例计算,为某气象卫星转发器中的SCPC载波的功率和频率设计提供了有用的结论。限于篇幅,程序清单从略,仅列出主要框图和计算结果。