The Analysis and Prospect of TDD Mobile Communication System

TDD模式移动通信系统相对于FDD系统有着独特的优势,如支持不对称业务,高频谱利用率,设备复杂度低。在介绍TDD移动通信系统特点的基础上,针对当前出现的新技术,如MIMO、智能天线、Ad-hoc、自适应调制技术TD-LAS-CDMA等,结合TDD移动通信系统的特点,分析了各技术在实际系统应用中的优缺点,最后展望在该模式下移动通信系统的发展前景。The mobile communication system of TDD mode has unique advantages,such as providing asymmetry service,high spectrum utilization,and low complexity of devices.On the basis of introducing the system characteristic,the advantages and disadvantages of the new technologies according to the TDD system,such as MIMO,smart antenna,Ad-hoc,AMC,TD-LAS-CDMA,are analyzed in the paper.At last discusses the prospect of the TDD system

零延时RS-485接口电路的设计与应用

根据在研制节能灯寿命检测系统中,实际检测环境传输数据量大,实时性强的特点,对物理总线的拓扑结构和通信协议提出要求。采用零延时RS485接口电路,逻辑上采用主从式网络结构,物理结构上采用星型网络拓扑结构;设计出一种支持主从式网络结构的485HUB,经过通信协议的帧校验和帧超时的设计,进一步提高软件抗干扰的能力。测试结果表明,系统稳定可靠,抗干扰能力强

Bluetooth Headset Design and Implementation Based on CSR BC5-MME System

随着无线通信技术的发展,蓝牙耳机解决了传统耳机线束缚的问题,得到了广泛应用,迅速改变了人们的生活方式。为了切合实际开发需要,设计实现高性能蓝牙耳机成为迫切需求。通过对蓝牙耳机性能的需求分析,选择了基于CSr bC 5-MME嵌入式系统平台,设计并实现了蓝牙耳机MMI的相关功能。该平台性能优越,可定制性强,为后续产品的研发定下坚实的基础。With the progress of Wireless Communication technology development,Bluetooth wireless would change the human lifestyle from the cord to cordless when voice communication happen on short distance.It has already implemented in the world and got more and more impact.In order to meet the intention of company,the high performance in the Bluetooth headset is required.Based on analyzing the requirement,the CSR BC5-MME Embedded system has been chosen and fully satisfied.Through the process of the headset design and implementation,this platform would be foundation for the continuous product

基于Au1200无线车载视频监控的设计与实现

基于Au1200设计无线车载媒体处理系统,介绍系统中视频监控部分的设计方案,提出基于ffMPEg的软压缩方法,设计并实现了视频监控的实时采集、压缩和存储。利用ffMPEg软压缩方法,将采集到的视频数据实时压缩成视频文件存储于硬盘中,降低了系统成本,对实际嵌入式媒体处理系统的开发具有较大价值

Method for Video Quality Evaluation Based on HVS Properties

摘要：本文针对视频质量的评测应用，对传统峰值信噪比(PSNR)算法加以改进。通过在视频帧内图像和帧间图像的处理过程中引入人眼视觉系统(HVS)的主要特性，克服传统 PSNR 算法在序列质量检测应用方面的缺陷。方法在帧内图像处理上利用人眼对边缘轮廓失真具有较强敏感性的特点，设计了基于图像边缘的检测方案以提高对典型空域失真的检测性能；在帧间图像处理上，通过测量帧间时域能量的变化，获得序列在时域轴上的典型特征，并据此对空域检测结果进行修正。通过上述改进，算法能在保持传统 PSNR 算法简易性的同时，提升其检测结果与主观感受的相关性；同时算法的计算量并不复杂，易于在检测设备中实现系统集成 Abstract: A method for the objective video quality assessment is proposed. By using the Human Vision System (HVS) properties into the intra and inter frame processing, the proposed method can overcome the traditional Peak Signal-to-noise Ratio (PSNR) in the application of video quality evaluation. Based on the principle that human's eyes tend to be more sensible to the degradation happening in the edge of image, a detection scheme is designed to evaluate the distortion in the intra frame. By measuring the temporal energy, know the typical features in the temporal domain and then use them to modify the evaluation result of the spatial domain. The proposed method inherits the advantages of the traditional PSNR such as simpleness and convenience and has better correlation with the subjective perception. And it can be easily implemented and integrated in the equipment system of detection.京信研究基金资

Image qual ity evaluation based on visual masking effect and singular value decomposition

中文摘要:将人眼视觉特性和图像本征特性相结合 ,设计了一套基于视觉掩盖和奇异值分解的图像质量评测方法。根据人眼的视觉敏感性函数(CSF)将参考图像和待测图像做噪声掩盖处理 ,剔除视觉敏感区外的图像信息;然后 ,根据人眼视觉特性提取参考图像的纹理区和平坦区 ,并作为待测图像检测区的划分依据 ,分别计算参考图像和待测图像在各自纹理区 和平坦区的奇异值;最后 ,通过奇异值测度得到待测图像在纹理区和平坦区的质量劣化程度。实验表明:通过纹理区和平坦区的区分检测 ,可提高检测敏感度并据此判断劣化及影响程度。同时 ,检测结果的主观相似性(CC)可达到 0. 896 ,均方根误差(RMSE)为 5. 58 ,较 PSNR和 SSIM 具有更好的性能。该方法实现简单 ,便于系统集成 ,可在涉及视频及图像质量检测的领域得到较好应用。 英文摘要：A image quality evaluation method based on visual masking effect and singular value decom-position is proposed. According to t he Cont rast Sensibility Function (CSF) ,t he original image and the processed image are prep rocessed to remove the signals out side the sensible region. On the basis of t he property of t he Human Visual System ( HVS) , t he text ure and plat regions of the original image are extracted to used as a division standard. Then , the singular values of t he original and p rocessed images are calculated bot h in text ure and plat regions. Finally , by measuring the difference between the singular value met rics of the original and the processed images , the image quality can be evaluated. The experimental result s show that this method is sensible to t he errors perceived by human2being and can improve discrimination for t he distortion region. The cor relation between t he result and t he subjective score is 0. 896 and t he root mean square error (RMSE) is 5. 58 ,which shows t he method can be realized easily and can be embedded into t he application system.基金项目:广州京信研究基金资助项目(No. K81004

Single-carrier frequency domain equalization with joint MMSE and PIC in DS-CDMA

重叠剪切频域均衡联合并行干扰消除(OC-PIC-fdE)是一种较低复杂度的实现方法,能取得良好的误码性能。基于该方法,通过联合MMSE(最小均方误差)和并行干扰对每个用户求出最优的MMSE频域均衡系数,实现对原方法的改进。仿真结果表明,改进后的方法与原OC-PIC-fdE相比,计算复杂度几乎相同,但误码性能却可以得到很大提高。The single-carrier overlap-cut frequency-domain equalization(OC-FDE) proposed recently requires no GI(Guard interval) inserted between data blocks,having almost the same BER performance.OC-FDE combined with parallel interference cancellation(PIC),named OC-PIC-FDE is a low complexity frequency-domain implementation method,with good BER performance.Based on the method,this paper proposed the improved method,by inferring the MMSE factors related to the user,jointing MMSE and PIC.The simulation results show the improved method has the same complexity compared with OC-PIC-FDE,but the BER performance is better.国家重大科技专项(2013zx03003012-004

Accelerating Experiment Teaching Center Constructi on to Deepen Experiment Teaching Reform

中文摘要: 在介绍厦门大学电子信息实验教学示范中心建设历程基础上 , 总结了中心实验教学的管理体制改革和实验教学改革 的措施 , 通过以实验内容、学科建设与科研促进实验教学 , 以实验教改促进学生创新能力培养 , 以国际化、企业化联合共 建实验室等方面体现了该中心的特色。 英文摘要：This paper first introduces the hist ory of building lab teaching demonstrati on center . Then it summarizes reforms of experiment managementmethods and experi ment teachingmethods—that is, experi ment teaching is p romoted thr ough the experi mental content, subject building and scientific researches ; studentsπcreative capabilities are accelerated through reforms of experi menting and teaching; the center features the internati onalized and enter p rise building of the experi ment labs

集群通信语音调度系统研究与实现

集群通信是一种共享资源,共用信道设备及服务的多用途,高效能的调度通信系统,受到专家学者和IT通信界的普遍关注。本文介绍了集群通信的发展现状,并进行集群通信系统的方案设计,实现了系统的初始化配置功能,注册功能以及语音调度子系统

Implementation of Directshow-based H.264 Network Video Monitoring at Client

为了实现视频监控客户端对H.264实时播放,采用dIrECTSHOW与MfC相结合的方法,用dIrECTSHOW作为视频播放的驱动,从网络接收数据,完成缓存,解码显示及封装成MfC可调用的API,MfC用来设计户界面,对播放过程进行相应的控制,达到了播放从网络接收到的H.264视频的目的.经过PC机上验证,可以流畅地从网络上接收播放H.264视频流,并且丢包率很小。在此用dIrECTSHOW来实时流畅的播放从网络上接收到的H.264视频流。In order to realize the real-time broadcasting of H.264 at video monitoring client,a method that combines Directshow with MFC is adopted.Directshow taken as a drive of the video player receives data from the network,performs cache,decoding and display,and provides the API for MFC,which is used to design UI to control the process of playing.After verification on PC,the player can smoothly play the H.264 video stream received from network,and the packet loss rate is low.The innovation of this paper is to use Directshow to play smoothly real-time H.264 stream received from network