BROADCAST SCHEDULING WITH MIMO LINKS IN MULTI-HOP AD HOC NETWORKS

As the current medium access control protocols with Multiple Input Multiple Output （MIMO） links only bear point to point service, broadcast scheduling algorithm in ad hoc networks with MIMO links is proposed. The key to the proposed broadcast scheduling algorithm is the time slot scheduling algorithm which guarantees collisi~）n-free transmissions for every node and the mini- mum frame length. The proposed algorithm increases the simultaneous transmissions of MIMO links efficiently. Due to the interference null capacity of MIMO links, the interference node set of each node can decrease from two-hop neighbors to one-hop neighbors possibly. Simulation results show that our algorithm can greatly improve network capacity and decrease average packet delay.

Cooperative Covert Communication in Multi-Antenna Broadcast Channels

With the gradual popularization of 5G communications,the application of multi-antenna broadcasting technology has become widespread.Therefore,this study aims to investigate the wireless covert communication in the two-user cooperative multi-antenna broadcast channel.We focus on the issue that the deteriorated reliability and undetectability are mainly affected by the transmission power.To tackle this issue,we design a scheme based on beamforming to increase the reliability and undetectability of wireless covert communication in the multi-antenna broadcast channel.We first modeled and analyzed the cooperative multi-antenna broadcasting system,and put forward the target question.Then we use the SCA(successive convex approximation)algorithm to transform the target problem into a series of convex subproblems.Then the convex problems are solved and the covert channel capacity is calculated.In order to verify the effectiveness of the scheme,we conducted simulation verification.The simulation results show that the proposed beamforming scheme can effectively improve the reliability and undetectability of covert communication in multi-antenna broadcast channels.

Multi-User Semantic Fusion for Semantic Communications over Degraded Broadcast Channels

Degraded broadcast channels(DBC) are a typical multiuser communication scenario, Semantic communications over DBC still lack in-depth research. In this paper, we design a semantic communications approach based on multi-user semantic fusion for wireless image transmission over DBC. The transmitter extracts semantic features for two users separately and then effectively fuses them for broadcasting by leveraging semantic similarity. Unlike traditional allocation of time, power, or bandwidth, the semantic fusion scheme can dynamically control the weight of the semantic features of the two users to balance their performance. Considering the different channel state information(CSI) of both users over DBC,a DBC-Aware method is developed that embeds the CSI of both users into the joint source-channel coding encoder and fusion module to adapt to the channel.Experimental results show that the proposed system outperforms the traditional broadcasting schemes.

A Deep Learning Based Broadcast Approach for Image Semantic Communication over Fading Channels

We consider an image semantic communication system in a time-varying fading Gaussian MIMO channel,with a finite number of channel states.A deep learning-aided broadcast approach scheme is proposed to benefit the adaptive semantic transmission in terms of different channel states.We combine the classic broadcast approach with the image transformer to implement this adaptive joint source and channel coding(JSCC)scheme.Specifically,we utilize the neural network(NN)to jointly optimize the hierarchical image compression and superposition code mapping within this scheme.The learned transformers and codebooks allow recovering of the image with an adaptive quality and low error rate at the receiver side,in each channel state.The simulation results exhibit our proposed scheme can dynamically adapt the coding to the current channel state and outperform some existing intelligent schemes with the fixed coding block.

Design Method for Optimizing the Interactive Interface of Live Broadcasting Platform for the Elderly Users

In the era of network live broadcasting for everyone,the development of live broadcasting platforms is also more intelligent and diversified.However,in the face of a large group of elderly users,the interface interaction design mode used is still mainly based on the interaction mode for young groups,and is not designed for elderly users.Therefore,a design method for optimizing the interaction interface of live broadcasting platform for elderly users was proposed in this study.Firstly,the case study method and Delphi expert survey method were used to determine the design needs of elderly users and the design mode was analysed.Secondly,the orthogonal design principle was used to design a test sample of the interactive interface of live broadcasting platform applicable for the elderly users,and then a user evaluation system was established to calculate the weights of the design elements using hierarchical analysis,and then the predictive relationship between the design mode of the interactive interface of live broadcasting platform and the elderly users was established by Quantitative Theory I.Finally,Genetic Algorithm was applied to generate the optimized design scheme.The results showed that the design method based on the Genetic Algorithm and the combination of Quantitative Theory can scientifically and effectively optimize the design of the interactive interface of the live broadcasting platform for the elderly users,and improve the experience of the elderly users.

Theoretical Analysis and Design Implementation of FM Broadcast Receiving System based on SDR

ADALM Pluto is a software-defined radio product.Based on theoretical analysis,this paper designs a Frequency Modulation(FM)broadcast receiving system using ADALM Pluto as a wireless receiver on the Simulink platform.The simulation results show that the theoretical analysis is correct and the parameter settings are reasonable,and the Software-Defined Radio(SDR)has the characteristics of high performance,high ease of use,and low cost.

Programming Technology of IP Multicast and Broadcast Based on Socket

Beginning with the simple introduction of socket which is the most commonly used application program interfaces in UNIX/LINUX communication domain, the concrete programming procedures to realize multicast and broadcast based on socket is provided, according to TCP/IP protocol in LINUX system. The acquiring and converting of broadcast destination address and multicast address, the setting of multicast options, the joining in and withdrawing from the multicast group, and the receiving and sending of datagram are all demonstrated in it, the related system calls and simple explication of C programming are also included.

基于Broadcast模板的交互系统

本文提出了一种基于Ｂｒｏａｄｃａｓｔ模板开发交互系统的面向对象方法，并分析了此方法所带来的系统结构的清晰性、稳定性及软件部件的可重用性。

广播标记(Broadcast Flag)技术

近来,业界都在讨论广播标记(BroadcastFlag)技术。本文详细介绍了广播标记技术产生的背景、原理与实现,以及争论的焦点问题;最后针对广播标记技术是否可以应用于我国的数字电视领域给出了我们的看法和建议。

Wireless location algorithm using digital broadcasting signals based on neural network

In order to enhance the accuracy and reliability of wireless location under non-line-of-sight （NLOS） environments,a novel neural network （NN） location approach using the digital broadcasting signals is presented. By the learning ability of the NN and the closely approximate unknown function to any degree of desired accuracy,the input-output mapping relationship between coordinates and the measurement data of time of arrival （TOA） and time difference of arrival （TDOA） is established. A real-time learning algorithm based on the extended Kalman filter （EKF） is used to train the multilayer perceptron （MLP） network by treating the linkweights of a network as the states of the nonlinear dynamic system. Since the EKF-based learning algorithm approximately gives the minimum variance estimate of the linkweights,the convergence is improved in comparison with the backwards error propagation （BP） algorithm. Numerical results illustrate thatthe proposedalgorithmcanachieve enhanced accuracy,and the performance ofthe algorithmis betterthanthat of the BP-based NN algorithm and the least squares （LS） algorithm in the NLOS environments. Moreover,this location method does not depend on a particular distribution of the NLOS error and does not need line-of-sight （ LOS ） or NLOS identification.

使用Broadcast Disks方法分布的空中位图索引

提出一种使用BroadcastDisks算法来分布位图索引的空中索引方法,根据数据项访问概率,使用位图作为数据广播的索引,减少了移动终端等待数据时保持激活状态的时间,达到节能的目的。

基于区块链的车联网跨域数据安全传输系统设计

为有效应对车联网系统在数据传输过程中的安全问题,提出一种基于区块链的车联网跨域数据安全传输系统。该系统将车联网安全数据传输过程划分为注册、安全通信与数据共享三个关键环节。在注册阶段,车辆和路边单元需要通过可信机构完成注册,以确保其的身份合法性;在通信阶段,为了减少路边单元与车辆频繁认证,设计了跨域认证的方法,保障数据传输的可靠性和完整性,并引入假名来保护用户隐私;在共享阶段,文中设计了基于多线程遍历共享广播森林的事务广播算法,利用广度优先搜索思想建立广播森林,并使用多线程遍历进行数据事务广播传输。实验仿真结果显示,文中方案的签名计算成本减少70%,验证计算成本减少41%;其次,在ER模型下,相比使用Gossip协议进行事务数据传输,该方案中交通数据事务总时间降低了93%;在BA模型下降低了87%。

Godson-T众核体系结构上的Broadcast性能优化

Godson-T是中国科学院计算技术研究所计算机系统结构重点实验室先进微系统组正在研制开发的适合于超深亚微米工艺实现的大规模片上众核系统.Godson-T片上存储的单端口结构节省了芯片面积但制约了共享数据的读取效率.直接在Godson-T上实现传统的Broadcast算法需要大量的同步互斥开销,无法达到很好的性能提升.基于Godson-T体系结构,对数据共享的重要并行算法Broadcast进行优化,提高了Godson-T体系结构下的数据共读的效率.主要采取了以下3项技术:消除大规模的线程同步,建立源地址到目的地址的映射表和用汇编语言实现Broadcast的核心部分.优化后Broadcast在小核数为32时即可达到5.8倍加速比.

基于Android Broadcast的短信安全监听系统的设计和实现

在手机终端应用软件和移动业务呈现出多样化发展的同时,针对手机短信进行后台监听与窃取的恶意软件也大量出现,已经对手机信息安全构成了严重的威胁。从Android系统的Broadcast运行机制入手,设计一个具有捕获第三方恶意软件劫取短信行为的监测软件,全程对广播进行监听和行为捕获,终止短信被劫取、转发等恶意行为的发生。在经过测试试验后效果良好,可以有效地解决短信被泄露的问题。

New mixed broadcast scheduling approach using neural networks and graph coloring in wireless sensor network

Due to the mutual interference and sharing of wireless links in TDMA wireless sensor networks, conflicts will occur when data messages are transmitting between nodes. The broadcast scheduling problem （BSP） is aimed to schedule each node in different slot of fixed length frame at least once, and the objective of BSP is to seek for the optimal feasible solution, which has the shortest length of frame slots, as well as the maximum node transmission. A two-stage mixed algorithm based on a fuzzy Hopfield neural network is proposed to solve this BSP in wireless sensor network. In the first stage, a modified sequential vertex coloring algorithm is adopted to obtain a minimal TDMA frame length. In the second stage, the fuzzy Hopfleld network is utilized to maximize the channel utilization ratio. Experimental results, obtained from the running on three benchmark graphs, show that the algorithm can achieve better performance with shorter frame length and higher channel utilizing ratio than other exiting BSP solutions.

Broadcasting with Controlled Redundancy and Improved Localization in Wireless Sensor Networks

Wireless sensor networks （WSNs） consist of sensor nodes that broadcast a message within a network. Efficient broadcasting is a key requirement in sensor networks and has been a focal point of research over the last few years. There are many challenging tasks in the network, including redundancy control and sensor node localization that mainly depend on broadcasting. In this paper, we propose a broadcasting algorithm to control redundancy and improve localization （BACRIL） in WSNs. The proposed algorithm incorporates the benefits of the gossip protocol for optimizing message broadcasting within the network. Simulation results show a controlled level of redundancy, which is up to 57.6% if the number of sensor nodes deployed in a 500 m×500 m area are increased from 50 to 500.

Partially secret broadcasting,partially secret splitting with quantum entanglement

In this paper, we propose a classical secret broadcasting and splitting joint protocol in a quantum scenario. With those genuinely entangled states, the boss can always broadcast some of his secrets and split some others to multi- receivers at the same time. The efficiency of the joint protocol is also compared with that of two separate ones which realise classical secret broadcasting and classical secret splitting respectively, and based on the comparison we can see the promising advantage of our joint protocol is that it can realise the two tasks more efficiently and more conveniently.

Cryptanalysis and improvement of quantum broadcast communication and authentication protocol with a quantum one-time pad

The security of quantum broadcast communication（QBC） and authentication protocol based on Greenberger–Horne–Zeilinger（GHZ） state and quantum one-time pad is analyzed. It is shown that there are some security issues in this protocol.Firstly, an external eavesdropper can take the intercept–measure–resend attack strategy to eavesdrop on 0.369 bit of every bit of the identity string of each receiver without being detected. Meanwhile, 0.524 bit of every bit of the secret message can be eavesdropped on without being detected. Secondly, an inner receiver can take the intercept–measure–resend attack strategy to eavesdrop on half of the identity string of the other＇s definitely without being checked. In addition, an alternative attack called the CNOT-operation attack is discussed. As for the multi-party QBC protocol, the attack efficiency increases with the increase of the number of users. Finally, the QBC protocol is improved to a secure one.

Impact of small-world topologies on broadcasting for wireless sensor networks

Broadcasting is an important operation and been widely used in wireless sensor networks （WSNs）. These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial graphs that have much more clustered and much high path-length characteristics. After considering energy- efficient broadcasting in such networks, by combining the small-world characteristic of WSNs and the properties of ant algorithm to quickly identify an optimal path, small-world power-aware broadcast algorithm is introduced and evaluated. Given different densities of network, simulation results show that our algorithm significantly improves life of networks and also reduces communication distances and power consumption.

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.