高机动雷达对空情报传输系统设计

分析雷达对空情报传输系统,提出了以网络为基础的高机动雷达对空情报传输系统设计方案。     

SDH数字微波传输系统的关键技术及优点分析

本文主要介绍了SDH数字微波传输系统的设备组成、工作原理和关键技术。分析论述SDH数字微波传输系统较模拟系统的优点,主要是频谱利用率高和传输质量好。     

迪威视讯承建广东省公安厅高清晰图像传输系统

日前，迪威视讯在广东省公安厅高清晰图像传输系统的竞标中，因提出的解决方案贴近广东省公安厅需求，一举中标，迪威视迅将负责承建广东省公安厅高清晰图像传输系统。     

基于GPRS无线数据传输系统的设计与实现

随着无线通信技术的发展,利用移动运营商提供的GPRS无线网络实现数据传输,将是各种自动化系统的重要发展方向。系统自定义了GPRS通信协议,实现了一个可广泛移值的无线数据传输系统。该系统实时性高,可靠性高,且不受地域传输距离限制,同时能够适应突发性大数据量传输。     

高解析喷码机中的USB数据传输系统

针对现有喷码机通常采用RS-232作为数据传输系统接口存在传输速度慢的问题,本文基于通用串口数据总线(USB)的体系架构,设计了用于高解析喷码机的基于传输芯片PDIUSBD12和微控制器P89C60X2的USB数据传输系统,讨论了USB接口的硬件和软件设计方法,对传输速度进行测试。传输大量二维码图片数据的测试结果表明,采用该系统在数据传输时具有传输速度快,使用方便等优点,能够满足高解析喷码机需要的大数据量的传输要求。     

光纤有线电视传输系统检修技巧

光纤以其频带宽、损耗低、传输远、抗干扰能力强、高保真度、工作性能稳定可靠以及重量轻等优点越来越被广泛应用,成为主要的传输手段。下面就以有线电视光纤传输系统为例,探讨一下有关光纤传输系统的原理及其检修技巧。     

高性能水声信号前置放大与长线传输系统设计

对传统的水声信号水下采集水上处理系统进行了改进,前置级采用了高性能集成仪表放大器AD8221,并针对水听器阻容特性对输入端进行匹配设计。同时设计的传输系统可直接在供电线上传输信号,该传输系统具有带宽高,衰减低,输出阻抗低的特性,是一种较为理想的信号与电源共线传输系统。     

SDH数字微波传输系统原理及应用

SDH数字微波传输系统广泛用于国家级及省级广播电视微波传输干线电路中,它具有传输容量大,远距离传输质量高、抗自然灾害性强等优点,是广播电视节目信号传输的主力设备。在此简明阐述了数字微波传输系统的基本原理,并结合实际详细分析了SDH数字微波传输设备在我站的具体应用,为提高微波传输电路维护水平具有一定意义。     

SHDSL系统设计与实现

文章针对G.SHDSL远距离传输的要求和构想,设计了以CX28975为核心处理单元的远距离传输系统,解决了信号传输距离近、误码率高的问题,最后在此系统上测试了传输对称、全双工、可变速率信号的误码率和通信距离。     

基于嵌入式网络技术的UPS远程监控系统的设计与分析

在传统的监控系统中,数据和视频的传输需要通过专用的电缆来进行传输,存在功能单一、传输效率不高、传输距离较短的缺点。嵌入式技术在远程监控系统具有明显的优势,本文就基于嵌入式网络的UPS远程监控系统进行了技术分析,重点对其软硬件的设计方案进行探讨。     

小型视频光端机的开发与应用

论述了视频光纤传输系统的工作原理,对光端机部分主要电路作了详细介绍,并给出了视频光端机的性能指标。     

实现不等错误保护的最小发射功率AM-OFDM系统

 本文提出了在OFDM系统中实现数据不等错误保护传输的最小发射功率自适应调制算法.利用OFDM系统各个子载波功率增益不相同的特点,将子载波分组,不同的子载波组满足不同的传输质量和传输速率要求,传输不同重要性的数据,并且通过自适应调制调整每个子载波的发射功率和调制阶数,在实现数据不等错误保护传输的同时使得系统消耗的总发射功率最小.仿真结果表明,该算法能够根据输入数据的QoS要求,为不同重要性的数据提供不同的传输质量,并在保证传输质量和速率要求的前提下,使系统的总发射功率最小.     

预啁啾技术在2.5Gbit／s光传输系统中的实现

本文介绍了２．５Ｇｂｉｔ／ｓ光传输系统中预啁啾技术的实现，并对２．５Ｇｂｉｔ／ｓ光传输系统中的啁啾和自相位调制进行了理论分析，为高速光传输系统的研究提供了参考。     

高速光传输系统的带内非线性作用

分析了高速光传输系统中带内非线性作用的产生原因和影响．因素,通过数值仿真和分析,得到了结论：在抑制带内非线性作用方面,相位调制优于幅度调制;色散后补偿优于色散预补偿,对于功率较大的情况尤为明显;对于一定的发射功率,脉冲占空比有一个最优值。     

Experimental demonstration and analysis of all-optical label swapping based on RZ-DQPSK/IRZ-ASK modulation format

A novel optical return zero differential quadrature phase shifted keying/inverse return zero amplitude shifted keying(RZ-DQPSK/IRZ-ASK) orthogonal modulation format scheme for all-optical label swapping is analyzed theoretically and experimentally.The transmission characteristics of RZ-DQPSK/IRZ-ASK modulation format transmission system are demonstrated.Results show that high extinction ratio is obtained for IRZ-ASK label signal while at the same time the all-optical label swapping,differential quadrature p...     

A novel turbo GFDM-IM receiver for MIMO communications

Generalized frequency-division multiplexing (GFDM) is a candidate waveform for the fifth generation (5G) wireless communication systems. However, the carrier frequency offset (CFO) causing synchronization problem is very important for GFDM system. In this paper, we propose a turbo receiver with channel estimation, equalization and CFO compensation for MIMO (multiple input multiple output) GFDM system with index modulation (IM). So far, no related researches exist. This paper proposes a novel receiver to solve CFO compensation with two-path transmission and proposes a modified phase rotated conjugate cancellation (PRCC) algorithm for the receiver. On the other hand, GFDM with index modulation (GFDM-IM) can achieve better performance and lower peak-to-average power ratio (PAPR) than those of GFDM by using active index subcarrier. To reduce the system complexity, the log-likelihood ratio (LLR) criteria is also employed to search which subcarrier is active. Moreover, the Kalman filter is employed to trace the time-varying channels. The initial channel estimation is performed by the sparse pilot signals. In the simulations, we compare the proposed receiver with several existing schemes in different time-varying channels and modulations. The proposed scheme outperforms the existing schemes.     

紫外光通信调制方式的对比研究

紫外光非视距通信是一种新型的无线光通讯形式,近年来受到各军事强国越来越广泛的关注。详细分析了启闭键控调制(OOK)、脉冲位置调制(PPM)、差分脉冲位置调制(DPPM)和数字脉冲间隔调制(DPIM)的编码结构,然后从带宽需求、平均发射功率、传输容量和差错性能等方面对各种调制方式进行了仿真对比。结果表明,DPIM调制比PPM具有更高的传输容量和更少的带宽需求,并且解调对同步要求较低,实现更简易,并结合紫外LED阵列将作为今后实用化紫外光源的发展趋势,DPIM调制在未来紫外光通信系统的应用中将具有更大的优势。     

Novel C-IPDM Signal Format for Suppression of Polarization Mode Dispersion

A novel chirped intra-bit polarization diversity modulation (C-IPDM) signal format is proposed. The transmission performance of C-IPDM is compared to NRZ, RZ and the common IPDM in terms of the PMD tolerance by simulation in a 40 Gb/s system. The results show that the C-IPDM format can reduce the effects of second-order PMD significantly due to the chirping characteristic and the system Q-factor is increased especially in high PMD systems.     

A partial transmit sequence technique with error correction capability and low computation

Orthogonal frequency division multiplexing (OFDM) is a popular transmission technique in wireless communication. Although already widely addressed in many studies, OFDM still has flaws, one of which is the occurrence of high peak‐to‐average power ratio (PAPR) in the transmission signal. The partial transmit sequence (PTS) technique is one method adopted to reduce high PAPR in OFDM systems. However, as PTS utilizes phase factors to generate multiple candidate signals, large amounts of calculation and time are required to search the candidate signal with the minimal PAPR, which will then be adopted as the final transmission signal. This paper proposes a novel PAPR reduction method, which can be applied in OFDM systems with M‐ary phase‐shift keying modulation. It not only requires less computation but also possesses error correction capabilities. More precisely, the proposed method is to divide a block‐coded modulation code into the direct sum of a correcting subcode for encoding information bits and a scrambling subcode for generating phase factors. Our proposed method is a suboptimal technique with low computation, because it uses a genetic algorithm with a partheno‐crossover operator as the transmitted signal selection mechanism. Simulation results show our proposed method has better PAPR performance than the GA‐PTS scheme. Based on the simulation results in Figures 5 and 6, it is evident that our proposed method can be employed in any OFDM system by using M‐PSK modulation.Copyright © 2013 John Wiley & Sons, Ltd.     

智能反射面辅助广义空间调制性能分析

将智能反射面（Intelligent Reflecting Surface,IRS）技术引入索引调制（Index Modulation,IM）技术领域,可在保留各自优势的同时提高系统可靠性并实现高频谱效率。但现有方案在每时隙内仅激活一根天线,使得天线的利用率降低,且单天线激活时若想要进一步提高系统传输速率只能成倍增大发射天线数或提高调制阶数,从而影响系统性能。针对这一问题,提出了IRS辅助广义空间调制（Generalized Spatial Modulation,GSM）相关技术的方案,在发射端激活多根天线,使得在单位时间内相同天线数时每时隙传输的比特数增加。计算了该方案理论误码率上界,通过仿真验证了理论推导的正确性。