看得见的无线通信技术——可见光通信

可见光通信作为新一代信息技术,除了为移动通信拓展频谱资源外,还具备高速、大容量、安全、节能的技术特点。现有射频通信的5G、6G技术方案能耗很高,而照明、显示用的LED已经无处不在,所以可见光通信将来可用于实现普适的万物光互连。商用照明的荧光型LED器件的带宽有限,通过均衡技术已经把可见光通信系统的3 d B带宽拓展到了600 MHz,单路二进制开关键控实时通信速率达到了1.39 Gbps。如果采用高阶调制和波分复用技术,多色LED光源的非实时通信总速率已经超过15 Gbps。灯光上网、灯光定位和智能家居系统等创新应用证明了可见光通信与照明或显示融合不是梦,预示看得见的光无线通信将引起更大的技术变革。     

无线/水声通信浮标技术研究及其实现

本文研究并设计实现了一种用于浅海水声信道多速率通信的无线/水声通信(racom)浮标,介绍了其水声通信和无线通信技术方案和工程设计与实现。本文设计的浮标综合了水声通信、DSP信号处理和无线电通信等技术,也可以用作水声通信/传感网络中的无线/水声通信(racom)网关节点。海上试验验证了本浮标总体设计方案的可行性。海上试验中,浮标无线通信距离达到15.2 km,误码率不大于10 6;除2 kbps速率外,浮标各种速率的水声通信数据传输误码率都小于1%,最大通信作用距离达到9.6 km;同时,试验也验证了浮标与水下运动平台之间的通信功能。     

0.14 THz超高速无线通信系统实验研究

 介绍了0.14 THz超高速无线通信实验系统的主要组成部分和主要实验结果。从太赫兹电子学出发,基于太赫兹半导体器件和宽带数字调制解调技术,采用一种“低频段高速矢量调制＋谐波混频＋放大”的太赫兹高速信息传输技术路线,在国内首次成功实现了0.14 THz 0.5 km 10 Gb/s高速信号实时传输和软件化事后解调,同时进行了4路高清视频信号的传输与解调。     

基于跳频通信的移动机械遥控系统

为解决在同一个工作区域多个无线通信网络容易彼此干扰无法协同工作的问题,以移动机械工程车辆为控制对象,设计JRCJ500无线遥控系统,由用户手持终端接收用户操作指令,现场控制器驱动远程设备动作,实现对车辆的远程操作控制与状态信息反馈;采用STM32L低功耗处理器设计无线通信模块,选择公用通信频段,基于跳频扩频通信技术,约定无线通信数据格式与跳频频点,通过简单高效的跳频图案生成算法,在每一帧数据中添加同步字头,实现了无线通信网络的快速同步组网,保证了通信的稳定性,实现了在限定工作区域多台无线通信设备同时工作的应用需求。由于采用模块化设计,系统具有良好的通用性和可移植性,能够在多种复杂恶劣工作场合实现远程控制功能。     

高速相干光通信平衡探测器研究

通过对相干光通信平衡探测器原理及关键技术进行分析,设计了一套高速平衡探测系统,并在室内构建了相干光通信测试平台.测试实验发现:该平衡探测器可以实现不同速率的相干探测,可为相干光通信提供有利的条件.在2.5Gbps通信速率下直接探测时,单管灵敏度可以达到-26dBm,动态范围为-26~3dBm;在本振光为3dBm时,相干探测的灵敏度可以达到-46.5dBm,动态范围为-46.5~3dBm.     

双通道高速数据采集处理平台的设计与实现

为满足数字式测向接收机对高速数据采集和处理的需求,研制了高速数据采集处理平台,该平台基于ADC12D1800RF模数转换器实现了两路1.35GHz中频信号的带通采样,以Xilinx公司V7系列FPGA为数据处理器,采用高速DDR3作为存储设备解决了海量数据存储问题,并通过高速串行接口（GTX/SRIO）实现了大容量数据的实时传输。该平台的测试结果为：1.8GHz采样率时有效位数大于8bit,DDR3存储器的工作主频可达1333MHz,GTX接口在10Gbps速率下工作时,其误码率小于10-9,上述测试结果表明该平台可以高速、准确地实现信号采集、数据传输、存储和处理,达到了预期设计目标。     

基于ZigBee技术的水域污染远程智能监测系统设计

针对所监测水域范围较大实时监测能力不强,水质污染程度监测不准确等问题,提出构建基于基于ZigBee无线通信技术的智能水域污染程度监测系统,利用ZigBee无线通信技术与Internet网络将水质检测数据发送到远程水质监控中心进行汇总处理,监控中心的服务器可获取到所监控水域范围内所有水域的水质污染程度数据、污染发展趋势、主要污染物等信息。本文对水质检测传感器模块、ZigBee无线通信模块、单片机外围电路、模数转换电路等硬件进行了设计;系统软件设计了远程参数设置、驱动程序等内容。通过系统测试结果表明,该系统对于水质污染程度的检测准确率可达到98%以上,通信成功率达到100%,水质检测终端工作稳定可靠,通信速率满足实时监测要求,适用于各种水域环境的水质污染程度的监测需求。     

基于UVC LED的小型化紫外无线通信技术

紫外光通信技术具有低窃听、低位辨、全方位、全天候、抗干扰等优点,而基于紫外光灯的通信系统存在光源体积大、易碎、调制困难、通信速率低、功耗大等问题。设计了一种基于紫外C波段(UVC)LED的小型化无线通信系统方案,并对系统性能进行了理论分析。系统光源采用UVC LED,探测器采用日盲光电倍增管(PMT)和窄带紫外滤光片,通信系统采用开关键控(OOK)和脉冲位置调制(PPM)调制方案。仿真结果表明所设计的紫外无线通信系统可在200mW发射光功率情况下实现直径200m范围内的非视距语音通信和100mW发射光功率情况下实现250m的64Kbps准视距通信。     

UMFSK水声通信技术研究

在MFSK基础上,本文提出了UMFSK信道编码方法。采用窄带调频和跳频调制技术,故在一定程度上抑制了由多途效应引起的码内/码间干扰;提出了基于UMFSK的实时信道标校技术,可对信道进行稳键均衡,抗信道多途引起的码内干扰。进行了湖试,取得了试验数据并进行了数据分析。分析表明：UMFSK可抑制码元相消干涉引起的码内干扰,其效果随码元调频带宽的增大而变好;信道标校技术可对信道进行稳键均衡,并由于结构简单,可做到实时实现。基于UMFSK的误码率为10^-3（通信带宽2kHz,速率100-150bps)。     

40kW高频功率源系统设计

根据用户的实际要求,设计了一种高频功率放大系统。为了获得足够大的输出功率,采用了由功率分配器和功率合成器组成的四级合成方式,利用多个750W功放模块,实现了高达40kW的功率输出;设计了以PLC为核心的监控系统,对高频功率放大系统中的前级功放、末级功放等各个部分的运行状态进行监控,利用触摸屏实现人机交互操作。实验测试结果表明该系统的合成效率达到90%以上,满足了高频功率放大的要求,系统工作稳定、可靠,具备人机交互和远程控制等功能。     

Modeling and simulation of FBG based OCDMA-IsOWC system

Photonics have evolved from protracted fibers to dominant wireless system to look at the use of hybrid optical-wireless communication system into space technology. Inter-satellite optical wireless communication (IsOWC) systems, one of the important applications of optical-wireless communication, will be deployed in space in the near future. A significant improvement in BER at 5 Gbps is achieved along with the maximum length of ISL link between the two satellites by incorporating OFDM scheme in IsOWC systems than that of conventional IsOWC systems [9]. The work is further extended in this paper to prolong the ISL link with acceptable BER at 10 Gbps between two satellites in space by employing code division multiple access (CDMA) scheme due to its robustness against narrowband interference and an inherent low power spectral density. In this work, we have designed a model of FBG based CDMA-IsOWC system to establish a prolonged ISL link at data rate of 10 Gbps with SNR of 20 dB. Further, a comparison is also reported between our proposed FBG based CDMA-IsOWC system and OFDM-IsOWC system.     

40 Gbps–80 GHz PSK-MDM based Ro-FSO transmission system

Bandwidth shortage of wireless carriers is a global issue that has further led to investigating the use of millimeter wave (mm-wave) in broadband cellular communication infrastructure. Radio over free space (Ro-FSO) optical system provides seamless integration of radio and optical platforms and makes it suitable for millimeter applications. This work is focused on transmission of two phase shift key encoded independent radio channels, each carrying 20 Gbps–40 GHz data, by mode division multiplexing of two modes: Laguarre Gaussian (LG) 00 and Hermite Gaussian (HG) 01. Furthermore, the modal decomposition of both channels is reported in terms of power coupling coefficient.     

Enhanced colorless and broadcast capable symmetrical 10-Gbps bidirectional transmission in WDM-PON using RSOA and EAM

Here we proposed a novel architecture of wavelength division multiplexed-passive optical network (WDM-PON) in which the downlink unicast data, broadcast data and uplink unicast data transmission is possible with the symmetric data rate of 10 Gbps. At remote node (RN) cyclic wavelength routing property of array waveguide grating (AWG) and power splitting capacity of power splitter is used in the architecture so that broadcast channel can be overlaid on downlink unicast channels. At ONU carriers sent from central office (CO) is reused for upstream data transmission with the help of integration of a reflective semiconductor amplifier (RSOA) and an electro-absorption modulator (EAM) so there is no need of extra laser sources at ONUs which makes them colorless. EAM can be operated at very high speed; a modulation bandwidth of tens of GHz can be achieved. Broadcast channel causes a limited interference with downlink and uplink unicast channels so it does not affect the system performance. Since each channel has different wavelength so NRZ data is used which eliminates expensive DPSK receivers and detection becomes very easy. Simulation is performed with all channels having data rate of 10 Gbps having acceptable performance.     

基于国产工艺的高速并串转换电路设计

面向全国产化工艺的5 Gbps SerDes(Serializer/DESerializer,串化器/解串器)芯片的需求,设计了其中的20:1 Serializer(并串转换电路)。该并串转换电路基于国产GSMC 130 nm CMOS工艺设计,其内部电路结构设计采用了一级5:1模块和两级2:1模块级联方式,并由多相时钟发生器和分频器提供相应的时钟信号,将20路250 Mbps并行数据转换成1路5 Gbps的高速串行数据进行传输。在温度?40~100 °C、全工艺角环境、电路工作电压在1.08~1.32 V 的条件下,后仿真结果均显示该电路功能正确,能输出完整清晰的5 Gbps数据眼图, 满足设计需求。 其中在27 °C、TT Corner(典型值工艺角)、1.2 V工作电压条件下仿真结果表明该并串转换电路整体总功耗为39.12 mW、总抖动为8.34 ps、输出电压满摆幅为800 mV。     

Modeling of 2.5 Gbps-intersatellite link (ISL) in inter-satellite optical wireless communication (IsOWC) system

Free-space optics (FSO) has the combined features of most dominated telecommunication technologies: wireless and fiber optics. Many of the aspects of FSO are related to fiber optics with an important difference of transmission medium which is air/free space rather than the glass of the fiber-optic cable. Inter-satellite optical wireless communication systems (IsOWC), one of the important applications of FSO/WSO technology, will be deployed in space in the near future as such systems provide a high bandwidth, small size, light weight, low power and low cost alternative to present microwave satellite systems. In this paper, we have designed a model of IsOWC system using OPTI-SYSTEM™ simulator to establish an inter-satellite link (ISL) between two satellites estranged by a distance of 1000 km at data rate of 2.5 Gbps which is not reported in previous investigated works.     

一种新型基于并行光传输的HDMI线缆的研制

 介绍了一款基于并行光纤通信技术的高清视频信号(high-definition multimedia interface, HDMI）传输线缆的研制技术方案。这种新型HDMI线缆采用垂直腔面发射激光器(vertical cavity surface emitting laser, VCSEL）阵列作为发射端,光电探测器（photodiode, PD）阵列作为接收端,两者之间采用多模光纤阵列互连,通过将电信号转变为光信号传输解决了铜缆损耗对电信号传输速率和传输距离的限制。与铜缆HDMI线相比,这种新型HDMI线能够以4信道×3.4Gbps的传输速率实现长达300m的传输距离,为当前高清视频信号和下一代超高清视频信号远距离传输提供了可行的技术方案。     

基于VPX总线的高速数字电路测试系统研究及应用

为解决战略预警雷达、舰载一体化等重点型号雷达中高速数字电路模块的维护能力,设计了基于VPX总线的高速数字电路自动测试系统,通过自研基于VPX总线的多功能测试模块、光纤测试模块,以及通用VPX背板,再结合通用的仪器设备构建测试系统,可兼顾多个型号雷达高速数字电路模块的测试。该系统可提供10路光纤通道,波特率最高为3.2Gbps;16路GPIO信号,中断响应时间＜50us;14路Rocket IO信号,传输速率2.5Gbps;4路*4Rapid IO信号,传输速率3.125Gbps。研究及实测结果表明该系统可解决基于VPX总线的高速数字电路模块的测试。     

Study of Internal Wavelength Locker Integrated 10 Gbps Electro-Absorption Modulated Laser Modules in Metro DWDM Applications

Several different divergences are tested in the several internal wavelength locker schemes for 10 Gbps electro-absorption modulated laser (EML) module. A 10 Gbps EML module with a simple and robust internal wavelength locker for metro dense WDM application is successfully demonstrated. The wavelength aging over 2000 h is done at elevated temperature of 70°C. The average wavelength drift of 10 modules is measured to be ± 5 pm. These modules can be successfully applied to the 10 Gbps DWDM systems with 50 GHz channel spacing.     

Performance analysis of LDPC codes on OOK terahertz wireless channels

Atmospheric absorption, scattering, and scintillation are the major causes to deteriorate the transmission quality of terahertz(THz) wireless communications. An error control coding scheme based on low density parity check(LDPC) codes with soft decision decoding algorithm is proposed to improve the bit-error-rate(BER) performance of an on-off keying(OOK) modulated THz signal through atmospheric channel. The THz wave propagation characteristics and channel model in atmosphere is set up. Numerical simulations validate the great performance of LDPC codes against the atmospheric fading and demonstrate the huge potential in future ultra-high speed beyond Gbps THz communications.     

一种新颖的供热管网隐性气体泄漏检测系统设计

供热管网由于管线距离长、高空架设结构不统一,导致其隐性热量泄露严重且很难发现。设计了一种新颖的供热管网隐性泄漏检测系统。采用光离子传感器PID-A1, 通过热电偶的阻值随燃烧热量来影响初始电压的变化进而对管线隐性泄露气体进行反映并检测,采用HUAWEI CM无线模块,完成全部PID-A1检测数据的无线接收、发射、基带信号处理和音频信号处理并传递数据到OPA4340数据采集模块,采用高速数字信号处理MCU芯片AT89C58实时处理采集到的数据,最终实现了供热管网隐性气体泄漏的检测。软件设计通过直接焓值法优化数据MCU处理模块的中央控制器运算性能,采用最小二乘法增强热量采集温度的效率和精度,确保检测系统的低功耗和高效率。最后进行仿真实验,实验结果表明: 本文系统的节能量比传统系统平均节能120J,并且本文系统的运算效率优于传统系统,提高22%左右,检测误差在2%以内,说明本系统的具用很强的可用性和推广价值。