Real-time Audio &Video Transmission System Based on Visible Light Communication

With the increasing popularity of solid sate lighting devices, Visible Light Communication (VLC) is globally recognized as an advanced and promising technology to realize short-range, high speed as well as large capacity wireless data transmission. In this paper, we propose a prototype of real-time audio and video broadcast system using inexpensive commercially available light emitting diode (LED) lamps. Experimental results show that real-time high quality audio and video with the maximum distance of 3 m can be achieved through proper layout of LED sources and improvement of concentration effects. Lighting model within room environment is designed and simulated which indicates close relationship between layout of light sources and distribution of illuminance.

Modeling and Statistical Properties Research on Online Real-Time Information Transmission Network

In this paper, the model of the online real-time information transmission network, such as wechat, micro-blog, and QQ network, is proposed and built, based on the connection properties between users of the online real-time information transmission network, and combined with the local world evolving characteristics in complex network, then the statistical topological properties of the network is obtained by numerical simulation. Furthermore, we simulated the process of information transmission on the network, according to the actual characteristics of the online real-time information transmission. Statistics show that the degree distribution presents the characteristics of scale free network, presenting power law distribution, while the average path length, the average clustering coefficient and the average size of the network also has a power-law relationship, moreover, the model parameters has no effect on power-law exponent. The spread of information on the network represents obvious fluctuation scaling, reflecting the characteristics that information transmission fluctuates over time.

Real-time performance of periodic data transmission in EPA industrial Ethernet

To evaluate and improve the real-time performance of Ethernet for plant automation（EPA） industrial Ethernet,the real-time performance of EPA periodic data transmission was theoretically and experimentally studied.By analyzing information transmission regularity and EPA deterministic scheduling mechanism,periodic messages were categorized as different modes according to their entering-queue time.The scheduling characteristics and delivery time of each mode and their interacting relations were studied,during which the models of real-time performance of periodic information transmission in EPA system were established.On this basis,an experimental platform is developed to test the delivery time of periodic messages transmission in EPA system.According to the analysis and the experiment,the main factors that limit the real-time performance of EPA periodic data transmission and the improvement methods were proposed.

Transmission Considerations with QoS Support to Deliver Real-Time Distributed Speech Recognition Applications

Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.

Development of 16-channels Compact EEG System Using Real-time High-speed Wireless Transmission

For the convenience of people with disability and for normal people, a demand for intelligent interfaces is ever increasing and therefore related studies are actively being conducted. Recently a study is being conducted to develop an interface through face expression, movement of the body and eye movements, and further more active attempts to use electrical signals(brainwave, electrocardiogram, electromyogram) measured from the human body is also actively being progressed. In addition, the development and the usage of mobile devices and smart devices are promoting these research activities even more. The brainwave is measured by electrical activities between nerve cells in the cerebral cortex using scalp electrodes. The brainwave is mainly used for diagnosis and treatment of diseases such as epilepsy, encephalitis, brain tumors and brain damage. As a result, the brainwave measurement methods and analytical methods were developed. Interface using the brainwave will not go through language or body behavior which is the result of the information processed by the brain but will pass directly to the system providing a brain-computer interface (BCI). This is possible because a variety of the brainwave appears depending on the human’s physical and mental state. Using the brainwave with the intelligent brain-computer interface or combining it with mobile devices and smart devices, regardless of space constraints, the brainwave measurement should be possible.[4,7] In this study, in order to measure the brainwave without spatial constraint, 16 channel compact brainwave measurements system using a high-speed wireless communications were designed. It was designed with a 16 channel to classify the various brainwave patterns that appear and for estimating the location of the nerve cells that triggered the brainwave. And in order to transmit the brainwave data within the channel without loss, a high-speed wireless communication must be possible that can enable a high-speed wireless transmission more sufficient than the Bluetooth, therefore, 802.11 compliant Wi-Fi communication methods were used to transfer the data to the PC. In addition, by using an analog front-end IC having a single-chip configuration with real-time digital filters, the miniaturization of the system was implemented and in order to verify the system Eye-blocking was used to observe the changes in the EEG signal.

Development of TaqMan-based Real-time PCR Assay for Detecting Transmissible Gastroenteritis Virus and Its Application in Vaccine Evaluation

[Objective] This study aimed to establish a TaqMan-based real-time PCR assay for detecting transmissible gastroenteritis virus （TGEV）. [Method] Primers and a probe were designed according to the conserved sequence of N gene in TGEV genome. After gradient dilution, the recombinant plasmid harboring the N gene was used as a standard for real-time PCR assay to establish the standard curve. [Re- sult] The results showed that the established real-time PCR assay exhibited a good linear relationship within the range of 102-10^10 copies/ul; the correlation coefficient was above 0.99 and the amplification efficiency ranged from 90% to 110%. The de- tection limit of real-time PCR assay for TGEV was 10 copies/μl, suggesting a high sensitivity; there was no cross reaction with other porcine viruses, indicating a good specificity; coefficients of variation within and among batches were lower than 3%, suggesting a good repeatability. The established real-time PCR method could be ap- plied in quantitative analysis and evaluation of the immune efficacy of TGEV vac- cines and detection of TGEV in clinical samples. [Conclusion] The TaqMan-based real-time PCR assay established in this study is highly sensitive and specific, which can provide technical means for the epidemiological survey of TGEV, development of TGEV vaccines and investigation of the pathogenesis of TGE.

Research on fast real-time adaptive audio mixing in multimedia conference

In multimedia conference, the capability of audio processing is basic and requires more for real-time criteria. In this article, we categorize and analyze the schemes, and provide several multipoint speech audio mixing schemes using weighted algorithm, which meet the demand of practical needs for real-time multipoint speech mixing, for which the ASW and AEW schemes are especially recommended. Applying the adaptive algorithms, the high-performance schemes we provide do not use the saturation operation widely used in multimedia processing. Therefore, no additional noise will be added to the output. The above adaptive algorithms have relatively low computational complexity and good hearing perceptibility. The schemes are designed for parallel processing, and can be easily implemented with hardware, such as DSPs, and widely applied in multimedia conference systems.

Design and implementation of multi-hop video transmission experiment system in VANET

Abts ract A wireless mutl i-hop videot ransmission experiment system is designed and implemented for vehiculra ad-hoc networks VANET and the rt ansm ission control protocol and routing protocol are proposed. This system in tegrates the embedded Linux system witha n ARM kernel and oc ns ists of a S3C6410 main control module a wirel ss local arean etwork WLAN card a LCD screne and so on.In the scenario of a wireless multi-hop video transmission both the H.264 and JPEG are used and their performances such as the compression rate delay and frame loss rate are analyzed in theory andc ompared in the experiment.The system is tested in the real indoor and outdoor environment.The results show that the scheme of the multi-hop video transmission experiment system can be applicable for VANET and multiple scenes and the transmission control protocol and routing protocol proposed can achieve real-time transmission and meet multi-hop requirements.

Design and Analysis of Traffic Information Transmission System Based on Visible Light Communication

Visible Light Communication( VLC) based on LED is a new wireless communication technology with high response rate and good modulation characteristics in the wavelengths of 380- 780 nm. Compared with conventional methods,the waveband of VLC is harmless to human and safe to communication because of no magnetism radiation. An audio information transmission system using LED traffic lights is presented based on VLC technology. The system is consisted of transmitting terminal,receiving terminal and communication channel. Some experiments were made under real communication environment. The experimental results showed that the traffic information transmission system works steadily with good communication quality and achieves the purpose of transmitting audio information through LED traffic lights,with a data transfer rate up to 250 kbps over a distance of 5 meters.

A real-time AI-assisted seismic monitoring system based on new nodal stations with 4G telemetry and its application in the Yangbi M_(S) 6.4 aftershock monitoring in southwest China

A rapidly deployable dense seismic monitoring system which is capable of transmitting acquired data in real time and analyzing data automatically is crucial in seismic hazard mitigation after a major earthquake.However,it is rather difficult for current seismic nodal stations to transmit data in real time for an extended period of time,and it usually takes a great amount of time to process the acquired data manually.To monitor earthquakes in real time flexibly,we develop a mobile integrated seismic monitoring system consisting of newly developed nodal units with 4G telemetry and a real-time AI-assisted automatic data processing workflow.The integrated system is convenient for deployment and has been successfully applied in monitoring the aftershocks of the Yangbi M_(S) 6.4 earthquake occurred on May 21,2021 in Yangbi County,Dali,Yunnan in southwest China.The acquired seismic data are transmitted almost in real time through the 4G cellular network,and then processed automat-ically for event detection,positioning,magnitude calculation and source mechanism inversion.From tens of seconds to a couple of minutes at most,the final seismic attributes can be presented remotely to the end users through the integrated system.From May 27 to June 17,the real-time system has detected and located 7905 aftershocks in the Yangbi area before the internal batteries exhausted,far more than the catalog provided by China Earthquake Networks Center using the regional permanent stations.The initial application of this inte-grated real-time monitoring system is promising,and we anticipate the advent of a new era for Real-time Intelligent Array Seismology(RIAS),for better monitoring and understanding the subsurface dynamic pro-cesses caused by Earth's internal forces as well as anthropogenic activities.

Priority-Based Real-Time Stream Coding over Multi-Channel with Packet Erasures

Multi-channel can be used to provide higher transmission ability to the bandwidth-intensive and delay-sensitive real-time streams. However, traditional channel capacity theories and coding schemes are seldom designed for the real-time streams with strict delay constraint, especially in multi-channel context. This paper considers a real-time stream system, where real-time messages with different importance should be transmitted through several packet erasure channels, and be decoded by the receiver within a fixed delay. Based on window erasure channels and i.i.d.(identically and independently distributed) erasure channels, we derive the Multi-channel Real-time Stream Transmission(MRST) capacity models for Symmetric Real-time(SR) streams and Asymmetric Real-time(AR) streams respectively. Moreover, for window erasures, a Maximum Equilibrium Intra-session Code(MEIC) is presented for SR and AR streams, and is shown able to asymptotically achieve the theoretical MRST capacity. For i.i.d. erasures, we propose an Adaptive Maximum Equilibrium Intra-session Code(AMEIC), and then prove AMEIC can closely approach the MRST transmission capacity. Finally, the performances of the proposed codes are verified by simulations.

A Method of Insulator’s NSDD Measurement and Its Device Based on Laser Transmission Principle

Accuracy measurement of the Non-soluble Deposit Density (NSDD) on the insulator surface is very important for the transmission line anti-pollution flashover works. A method to measure the NSDD on double sheds porcelain insulator surface based on laser transmission principle is proposed in this paper. Laser unit and luminous intensity sensor are installed between the up and down surface of the double sheds porcelain insulators, two glass tablets are put between the double sheds. The contamination on the glass tablets will influence the luminous intensity that reaches the intensity sensor. The luminous signal is changed to electrical signal, and the insulator’s NSDD could be obtained based on the difference of luminous intensity. The device can be used in online monitoring of the insulator's NSDD condition on the insulator surface.

面向BLE Audio的改进DSDV路由算法

在需要频繁传输音频的大规模蓝牙网络中,传统的DSDV路由算法会引入极高的时延和功耗。为了实现低功耗低时延的蓝牙网络音频传输,将BLE Audio的同步传输链路引入DSDV路由算法中,并结合根据节点状态自适应改变广播周期的机制,提出了一种面向BLE Audio的改进DSDV路由算法。并且在BLE Audio硬件平台开发和实现了提出的路由算法。实际测试结果表明,该算法不仅能够降低节点功耗,同时能够极大降低音频数据包的端到端时延。

BLE Audio技术及其在电视互动应用中的实时音频通信

随着智能电视的普及和电视观看体验的不断提升,用户对于更方便、更自由的音频传输方式的需求日益增加。蓝牙低功耗音频(Bluetooth Low Energy Audio,BLE Audio)技术是一种基于蓝牙低功耗(Bluetooth Low Energy,BLE)标准的无线音频传输技术,由BLE技术升级而来,为音频设备提供高质量的无线音频传输,同时具有低功耗、低延迟和简单的设备连接特性。BLE Audio技术适用于各种应用场景,包括耳机、音箱、智能家居系统以及可穿戴设备等。基于此,详细分析BLE、BLE Audio技术以及BLE Audio技术在电视互动场景中的应用。

基于NBVTH算法的军用窄带信道视频传输研究

随着信息技术快速发展,音视频传输广泛应用在军民用领域。针对军用环境通信传输带宽窄、电磁干扰强、网络稳定性低等特点,迫切需要对军用窄带信道下音视传输频编码进行优化。介绍了适应军用窄带信道传输的视频编码框架和最新技术,提出了基于HEVC标准优化的窄带视频传输(NBVTH)算法,并在压缩比、压缩图像质量、编码时延等关键技术指标方面,将NBVTH算法与常用的H.264/AVC编码进行了性能对比分析。试验结果表明,NBVTH算法明显提升了编码性能,更加适用于军用窄带信道的视频传输。

新媒体时代芜湖文化遗产的音频传播研究

新媒体时代,不同类型的传播方式让古老的芜湖文化遗产焕发出了新的活力。作者首先介绍了芜湖文化遗产和新媒体时代芜湖文化遗产音频传播现状,接着分析了音频传播对芜湖文化遗产的影响,最后在此基础上,提出了一系列新媒体时代芜湖文化遗产的音频传播策略。

网络多媒体传输协议在物联网音频监控系统中的应用

介绍网络多媒体传输协议的基本原理,探讨其在音频监控中的应用,包括音频数据捕获、编码、传输、接收及解码等环节。基于此,设计一个基于网络多媒体传输协议的物联网音频监控系统架构,并对其功能进行设计。最后进行系统运行测试,验证该架构的可行性和有效性。

斜射式超声波跨金属厚壁无线通信系统

跨金属无线传输是超声波通信的重要应用场景之一。实际应用中超声波在金属/超声波换能器界面处因反射而造成回波干扰是这类通信系统的天然缺陷。尽管利用回声消除技术能一定程度地克服回波干扰,但这需要调用大量电路硬件或计算资源。该文在超声波跨金属厚壁通信系统中摒弃传统的直射式探头而选用入射角为45◦的斜射式探头作为超声波发射和接收换能器,由于斜射式探头偏转了超声波在金属信道内的反射路径,从而大幅降低换能器接收到的回波。在不进行回波消除的前提下,以STM32为主控芯片和自制信号调理电路搭建了一套斜射式超声波跨金属厚壁无线通信系统,同时将之与选用直射式探头作为超声波换能器的通信系统进行对比验证。研究表明,在接收信噪比方面斜射式系统(19.52 dB)远优于直射式系统(9.24 dB),在穿透60 mm的厚铝板时系统实时通信速率达到1.2 Mbit/s,并可实现实时声频传输。

基于软件无线电的高清音频传输系统设计

在5G时代背景下,随着高清音频传输需求的不断增长,对于传输速率、延迟、稳定性等方面提出了更高的要求。为了应对更高的传输需求,文中基于软件无线电技术,使用eLabRadio软件和eNodeX 10F-DS硬件设备设计实现了一个高清音频传输系统。该系统采用CVSD编码、卷积和差分组合信道编码、BPSK调制等关键技术,构建了无硬件仿真、自发自收和一发一收三种不同工作模式的音频传输系统。经过测试验证可知:当发射衰减为10 dB、接收增益为50 dB时,该系统能够在0~6 m距离内实现高质量、低延迟的音频文件传输,抗干扰能力强;同时固定发送设备与接收设备之间的距离为2 m、发送衰减为10 dB,当接收增益为30 dB和在50~60 dB范围内时,音频的传输效果较好。

基于软件无线电的音视频通信一体化方案

为解决传统无线电平台对音视频传输误码率高、速率慢及设计复杂等问题,设计并提出基于ZYNQ和AD9361软件无线电方案。方案以IEEE802.11a协议为标准使用OFDM作为其主要调制技术,并通过网口实现ZYNQ与电脑主机之间的视频数据交互。功能测试结果表明,通过该方案设计的系统在天线接收范围内能持续保持数据误码率为零,并可根据实际需求灵活调整参数。此外,设计的一体化终端具有高实用性、强可扩展性和低复杂性,可广泛应用于各种环境。方案为音视频通信一体化提供全新的解决思路和方法,对无线视频通信产品开发具有较好的价值和现实意义。