战术电台多波形技术分析

基于通用硬件平台及软件无线电技术运行多波形的新型战术电台,是实现多频段多模式多用途、互连互通互操作的关键战术通信装备之一。分析了多波形电台的基本技术内涵;给出了国内多波形电台技术发展途径建议,重点在于开发符合通用设计规范的硬件平台、系统操作控制软件平台及波形库软件。     

The WINLAB Network Centric Cognitive Radio Hardware Platform—WiNC2R

This paper presents the design goals and architecture of WiNC2R—the WINLAB Network Centric Cognitive radio hardware platform. The platform has been designed for flexible processing at both the radio physical layer and MAC/network layers with sustained bit-rates of ~10 Mbps and higher. The hardware prototype supports multi band operation with fast spectrum scanning, the ability to dynamically switch between a number of OFDM and DSSS modems and multiple MAC protocols. The radio modems, MAC, and network-layer protocols are implemented in a flexible manner using general-purpose processing engines and a set of dynamically configurable hardware accelerators. An FPGA based platform implementation currently in progress is described in terms of key hardware components including the software-defined modem, the flexible MAC engine and network-level processor. Preliminary prototyping results are reported, and a roadmap for further evolution of the WiNC2R board is provided.     

基于OFDM波形的雷达和通信一体化研究

雷达和通信一体化是一种具有信息交互和目标信息探测功能的系统,是近年来雷达和通信技术发展的一个重要方向.OFDM技术是公认的4G关键技术,具有良好的抗多径和抗干扰能力,并且OFDM技术在雷达领域具有很高的研究价值,基于此提出一种基于OFDM波形的雷达和通信一体化系统模型,阐述信道估计在雷达和通信一体化系统中的重要作用,对其中信道估计算法进行研究,搭建仿真平台进行了仿真实验,对几种基于导频的信道估计算法的性能进行了分析比较.     

Design and rapid prototyping of SCA-compliant public safety P25 waveform and P25?CFM3TR?CVoIP bridge

Establishing radio communication between military commanders, soldiers and law enforcement officers is an important enabling capability to facilitate interoperability. The Joint Tactical Radio System (JTRS) program is enabling communications within the military by implementing different military radio waveforms on software defined radio (SDR) platforms. It is logical to include a Project 25 (P25) public safety waveform in the JTRS waveform portfolio. This paper describes the rapid development of a P25 waveform on a surrogate JTRS SDR platform. The development process and methodology, which starts from a platform agnostic executable waveform model in Matlab, through an intermediate implementation using open tools on generic platforms, to the final platform-specific implementation, is introduced and discussed. This paper shows that adopting this methodology can speed up waveform development and porting. Furthermore, this paper presents the design and implementation of a three way voice bridge among P25, the future multiband multiwaveform modular tactical radio (FM3TR), and voice over Internet Protocol (VoIP), with software communication architecture (SCA) compliant implementation for both the P25 and FM3TR waveforms. This paper shows that critical issues such as interoperability can be tackled efficiently by leveraging SDR and SCA.     

OFDM for data communication over mobile radio FM channels. I.Analysis and experimental results

The performance of OFDM/FM modulation for digital communication over Rayleigh-fading mobile radio channels is described. The use of orthogonal frequency division multiplexing (OFDM) over mobile radio channels was proposed by Cimini (1985). OFDM transmits blocks of bits in parallel and reduces the bit error rate (BER) by averaging the effects of fading over the bits in the block. OFDM/FM is a modulation technique in which the OFDM baseband signal is used to modulate an FM transmitter. OFDM/FM can be implemented simply and inexpensively by retrofitting existing FM communication systems. Expressions are derived for the BER and word error rate (WER) within a block when each subchannel is QAM-modulated. Several numerical methods are developed to evaluate the overall BER and WER. An experimental OFDM/FM system was implemented and tested using unmodified VHF FM radio equipment and a fading channel simulator. The BER and WER results obtained from the hardware measurements agree closely with the numerical results     

雷达通信一体化研究现状与发展趋势

雷达通信一体化通过一套共用的硬件设备实现雷达探测与通信传输,相比于传统单一的雷达或者通信设备,更易集成化、小型化和高效利用频谱。该文系统地介绍了雷达通信一体化的原理与特点,指出了一体化研究中亟需解决的问题,从典型的基于线性调频(LFM)的雷达通信一体化信号出发,全面梳理了国内外针对雷达通信一体化的相关研究,着重归纳了正交频分复用(OFDM)与多入多出(MIMO)技术在雷达通信一体化波形设计、信号处理、一体化系统设计等几个重点方向的研究进展,并分析了雷达通信一体化未来的可能发展趋势及其在军事领域和民用智能交通领域的重要应用前景。

     

基于L频段数字航空通信系统1的F-OFDM波形设计

随着航空飞行器种类和数量的激增以及第五代(5G)移动通信系统和物联网(IoT)时代的到来,下一代航空无线通信系统面临着高安全性、大传输容量、低延时、强鲁棒性、高灵活性和综合业务提供等新的挑战.为此,提出了一种基于L频段数字航空通信系统1(L-DACS1)的滤波正交频分复用(F-OFDM)波形设计方法并探讨了可能的技术演进路径.首先引入了认知无线电、非连续载波干涉码OFDM和滤波器的思想,然后针对不同航空飞行器用户动态自适应配置波形参数.仿真结果表明,该方法得到的系统波形具有较低的带外辐射功率、优良的块误码率性能和较高的吞吐量增益.     

基于OFDM 波形的短波通信与超视距雷达集成实验研究

该文利用武汉大学新近研制的全数字主被动一体化高频地波雷达硬件平台,开展了短波通信与雷达探测的一体化实验研究。结合高频电波特定传播环境,首先从通信角度介绍了正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)在短波通信中的关键技术,然后从雷达探测角度分析了OFDM 参数设计准则及其对超视距雷达探测性能的影响,最后说明了通信信号解调与探测信息获取的处理流程及部分关键技术,并介绍了硬件平台、参数配置及实验结果。结果表明OFDM 波形是一种良好的雷达通信一体化信号,该技术对超视距雷达(Over-The-Horizon Radar, OTHR)组网探测研究具有重要意义。      

Instructions and hardware designs for accelerating SNOW 3G on a software-defined radio platform

Software-defined radio (SDR) is a new technology transitioning from research into commercial markets. SDR moves hardware-dominant baseband processing of multiple wireless communication protocols into software on a single chip. New cellular standards, such as HSPA+, LTE, and LTE+, require speeds in excess of 40 Mbps. SNOW 3G is a new stream cipher approved for use in these cellular protocols. Running SNOW 3G in software on our SDR platform provides a throughput of 19.1 Mbps per thread for confidentiality and 18.3 Mbps per thread for integrity. To have secure cellular communications in SDR platforms for these new protocols, the performance of security algorithms must be improved. This paper presents instruction set architecture (ISA) extensions and hardware designs for cellular confidentiality and integrity algorithms using SNOW 3G. Our ISA extensions and hardware designs are evaluated for the Sandbridge Sandblaster^? 3011 (SB3011) SDR platform. With our new SNOW 3G instructions, the performance of confidentiality and integrity improve by 70 and 2%, respectively. For confidentiality, power consumption increased by 2%, while energy decreased by 40%. For integrity, power consumption remained consistent, while energy decreased by 2%.     

基于SCA的软件无线电平台研究

本文在全面深刻理解SCA规范的基础上提出了一个具体方案来实现符合SCA规范的软件无线电系统。本技术方案包括系统的软硬件体系结构，基于SCA规范的通信波形的开发以及系统中频板的研制等，其中系统中频板的研制主要介绍PCI接口电路的设计，Vxworks实时操作系统下驱动程序的编写等。     

Dual symbol optimization‐based partial transmit sequence technique for PAPR reduction in WOLA‐OFDM waveform

Weighted overlap and add‐orthogonal frequency division multiplexing (WOLA‐OFDM) is a new waveform proposed recently for meeting the requirements of fifth generation (5G) telecommunication standards. In spite of being a serious 5G waveform candidate, WOLA‐OFDM is exposed to the problem of high peak to average power ratio (PAPR) similar to the other waveforms in which multicarrier transmission strategy is employed. Due to the overlapping nature of WOLA‐OFDM waveform, where the extension of the current symbol is overlapped with the extension of the previous symbol, it will not be efficient to apply conventional PTS (C‐PTS) directly to the WOLA‐OFDM waveform. Therefore, in this paper, we propose dual symbol optimization‐based partial transmit sequence (DSO‐PTS) technique for PAPR reduction in WOLA‐OFDM waveform. In our proposed technique, two adjacent symbols are jointly considered when searching for the optimal data block with minimum PAPR unlike the C‐PTS where the adjacent symbols are optimized individually. In the simulations, our proposed DSO‐PTS technique, C‐PTS, and GreenOFDM that is developed recently by modifying the conventional selective mapping (SLM) method are compared with each other with regard to PAPR reduction performance for different search numbers (SNs). In addition, the effects of DSO‐PTS, C‐PTS, and GreenOFDM on the amount of out of band (OOB) radiation in the power spectral density (PSD) graph of WOLA‐OFDM employing solid state power amplifier (SSPA) is measured for different SNs and input back off (IBO) values. According to the simulation results, our proposed DSO‐PTS technique clearly demonstrates a superior PAPR reduction and PSD performance.     

电台示教系统设计与实现

介绍某型电台示教系统的设计方法,详细说明系统的硬件和软件设计。为了达到更加直观、清楚地展现电台的工作过程,方便地进行性能测试和故障诊断的目的,提出将电台所有的结构和工作过程开放化、形象化的设计理念,采用将电台整体放大引出观测点的方法,使电台的各项功能、测试性能指标和信号波形能通过示教系统直观的展示。通过实验验证,该系统使用方便、性能稳定、工作过程形象直观,既能在教学中使用,也可用于测试和故障诊断。软件设计采用图形化程序语言LabVIEW作为软件的开发平台,并结合运用了数据库技术。     

Applying IP over wmATM technology to third generation wirelesscommunications

With the rapid development of third-generation wireless mobile communication systems worldwide, the wireless mobile ATM enhanced software radio platform has taken the lead in the implementation process, which helps construct a broadband wireless pipe and “IP over wmATM” open signaling suite to support various common air interfaces for the wireless industry. This article presents the implementational issues using the IP over wmATM solution for 3G broadband wireless mobile communication systems. It includes the design of the wmATM medium access controller, protocol stack, wmATM module definition, and software radio platform, as well as IP unified 3G wireless networks     

智能多载波波形调制系统:信号的产生与识别

移动通信应用场景逐渐呈现复杂化和多变化趋势,很难有一种普适性传输波形满足所有通信需求,这对多种波形的配合与协作提出了较高的要求。该文提出一种适用于复杂场景下的智能化多载波波形调制系统,发送端可通过波形激活因子选择产生合适的传输波形,接收端将不同波形信号的I/Q分量作为自适应因子,使用主成分分析法处理数据后送入智能波形识别网络(IWR-Net)完成信号的识别。所提系统融合深度学习网络,具有较为统一的硬件架构。仿真结果表明,所提方案在5G多场景下对不同发送波形识别准确率最高可达98.2%,并且在不同测试环境中具有良好的泛化性能。     

OFDM技术及在认知无线电中的应用

OFDM技术是一种无线环境下的高速多载波传输技术,抗频率选择性衰落或窄带干扰能力较强,同时又有很高的频谱利用率,适合在多径传播的无线移动信道中传输高速数据。论文分析了OFDM的基本原理,论述了其关键技术及优缺点。OFDM技术将成为未来无线通信中的核心技术,在认知无线电、4G移动通信和无线宽带接入等领域得到广泛的应用。     

联合AC-ICF和TR技术的多功能波形设计方法

要: 分布式网络雷达的多功能承载是目前雷达领域研究的一个热点,基于OFDM信号的雷达通信共享的多功能波形设计受到人们广泛关注,其核心问题之一是较高的包络峰均比（PMEPR）。基于OFDM信号,本文联合自适应限幅门限的迭代限幅滤波技术（AC-ICF）和子载波预留（TR）技术研究了一种面向分布式组网雷达的多功能波形设计方法。首先,建立雷达网络的OFDM信号模型。其次,联合AC-ICF和TR技术研究了低PMEPR的多功能波形设计方法。最后,通过计算机仿真验证了多功能波形设计方法的可行性,并对其中面临的问题进行了分析与讨论,同时对优化设计后波形的雷达和通信性能进行了简要分析。      

认知无线电系统动态可重构软件波形的开发

为了使未来的认知无线电系统具备有很强的灵活性,支持各种各样的波形,适应不断变化的外部环境,使用GNU Radio软件和USRP硬件搭建一个成本低,适用于认知无线电的软件波形开发平台。设置多个可动态在线调整的波形参数调节“旋钮”,和一个API用于实时接收和解析认知引擎的波形请求信息,调节波形参数。通过实验测试表明,该平台能很好地为认知无线电系统提供丰富的动态可重构软件波形。     

基于SCA架构的软件无线电数字系统主板设计

提出了一种基于SCA框架的新型软件无线电数字系统的解决方案,该方案充分利用了先进的DaVinci嵌入武技术以及最新的FPGA技术,对传统的软件无线电平台进行优化和改良.对系统进行功能划分,并且对各功能模块的框架以及硬件设计进行了详细的分析和阐述.与以往的无线电平台相比,该平台具有功能强大,可移植通用的嵌入式操作系统,使...     

基于SCA的软件无线电SoPC设计

软件通信体系架构为实现具有开放性、标准化、模块化的通用软件无线电平台提供了规范。为了实现无线通信系统的小型化,采用软硬件协同设计的方法构建了基于SCA的软件无线电SoPC系统,该系统实现了波形组件的动态配置和部署,以及硬件组件的部分重构。同时它具有效率高,体积小,功耗低,功能强的优点,具有很好的应用前景。     

OFDM新体制雷达研究现状与发展趋势

正交频分复用(OFDM)雷达是近些年才提出的一种新体制雷达,它借鉴了通信系统中正交多载频的原理,相比于传统雷达,具有一些独特的优势。该文系统地介绍了OFDM雷达的特点,全面梳理了国内外关于OFDM新体制雷达研究的文献,总结了信号特性与波形设计、信号处理、新体制雷达系统等几个重点方向的研究进展,并分析了OFDM雷达未来的几个发展趋势和应用前景。