Inter-Data Commonality Detection for Spectrum Monitoring in Wireless Sensor Networks

Cooperative spectrum monitoring with multiple sensors has been deemed as an efficient mechanism for improving the monitoring accuracy and enlarging the monitoring area in wireless sensor networks.However,there exists redundancy among the spectrum data collected by a sensor node within a data collection period,which may reduce the data uploading efficiency.In this paper,we investigate the inter-data commonality detection which describes how much two data have in common.We define common segment set and divide it into six categories firstly,then a method to measure a common segment set is conducted by extracting commonality between two files.Moreover,the existing algorithms fail in finding a good common segment set,so Common Data Measurement(CDM)algorithm that can identify a good common segment set based on inter-data commonality detection is proposed.Theoretical analysis proves that CDM algorithm achieves a good measurement for the commonality between two strings.In addition,we conduct an synthetic dataset which are produced randomly.Numerical results shows that CDM algorithm can get better performance in measuring commonality between two binary files compared with Greedy-String-Tiling(GST)algorithm and simple greedy algorithm.

Opportunistic spectrum sharing in software defined wireless network

Over the past few decades, the world has witnessed a rapid growth in mobile and wireless networks（MWNs） which significantly change human life. However, proliferating mobile demands lead to several intractable challenges that MWN has to face. Software-defined network is expected as a promising way for future network and has captured growing attention. Network virtualization is an essential feature in software-defined wireless network（SDWN）, and it brings two new entities, physical networks and virtual networks. Accordingly, efficiently assigning spectrum resource to virtual networks is one of the fundamental problems in SDWN. Directly orienting towards the spectrum resource allocation problem, firstly, the fluctuation features of virtual network requirements in SDWN are researched, and the opportunistic spectrum sharing method is introduced to SDWN. Then, the problem is proved as NP-hardness. After that, a dynamic programming and graph theory based spectrum sharing algorithm is proposed.Simulations demonstrate that the opportunistic spectrum sharing method conspicuously improves the system performance up to around 20%–30% in SDWN, and the proposed algorithm achieves more efficient performance.

A Fault-Tolerant Cooperative Spectrum Sensing Algorithm over Cognitive Radio Network Based on Wireless Sensor Network

A serious threat to cognitive radio networks that sense the spectrum in a cooperative manner is the transmission of false spectrum sensing data by malicious sensor nodes. SNR fluctuations due to wireless channel effects complicate handling such attackers even further. This enforces the system to acquire authentication. Actually, the decision maker needs to determine the reliability or trustworthiness of the shared data. In this paper, the evaluation process is considered as an estimation dilemma on a set of evidences obtained through sensor nodes that are coordinated in an underlying wireless sensor network. Then, a likelihood-based computational trust evaluation algorithm is proposed to determine the trustworthiness of each sensor node's data. The proposed procedure just uses the information which is obtained from the sensor nodes without any presumptions about node’s reliability. Numerical results confirm the effectiveness of the algorithm in eliminating malicious nodes or faulty nodes which are not necessarily conscious attackers.

Cooperative Spectrum Sensing for Cognitive Radio-Wireless Sensors Network Based on OR Rule Decision to Enhance Energy Consumption in Greenhouses

Wireless sensors networks (WSNs) combined with cognitive radio have developed and solved the limited space of the frequency spectrum. In this paper, we propose different types of spectrums sensing and their own decisions depend on the probabilities that applied into fusion center, and how these probabilities’ techniques help to enhance the energy consumption of WSNs. In the same way, the importance of designing balanced distribution between the wireless sensors networks and their own sinks. This research also provides an overview of security issues in CR-WSN, especially in Spectrum Sensing Data Falsification (SSDF) attacks that enforces harmful effects on spectrum sensing and spectrum sharing. We adopt OR rule as four types of CRSN sensing protocolin greenhouses application by using Matlab and Netsim simulators. Our results show that the designing balanced wireless sensors and their sinks in greenhouses are very significant to decrease the energy, which is due to the traffic congestion in the sink range area. Furthermore, by applying OR rule has enhanced the energy consumption, and improved the sensors network lifetime compared to cognitive radio network.

Towards 5th Generation Wireless Communication Systems

This paper introduces the general landscape of next-generation wireless communication systems （5G）, including the impetus and requirements of 5G and the candidate technologies that might help 5G achieve its goals. The following areas, which the author considers particularly relevant, are discussed： deteetion of and access to free spectrum over bands of a heterogeneous nature, ex- treme densification of networks （massive base station deployments）, extreme increase in the number of antennas in base station ar- rays and their interaction with a novel waveform, integration of both wireless and optical sides of telecom networks, and study of wireless networks from the perspective of complex systems science. The author discusses recent research conducted by his team in each of these research areas.

Media Access with Spatial Reuse for Cooperative Spectrum Sensing

The increasing interest for wireless communication services and scarcity of radio spectrum resources have created the need for a more flexible and efficient usage of the radio frequency bands. Cognitive Radio (CR) emerges as an important trend for a solution to this problem. Spectrum sensing is a crucial function in a CR system. Cooperative spectrum sensing can overcome fading and shadowing effects, and hence increase the reliability of primary user detection. In this paper we consider a system model of a dedicated detect-andforward wireless sensor network (DetF WSN) for cooperative spectrum sensing with k-out-of-n decision fusion in the presence of reporting channels errors. Using this model we consider the design of a spatial reuse media access control (MAC) protocol based on TDMA/OFDMA to resolve conflicts and conserve resources for intra-WSN communication. The influence of the MAC protocol on spectrum sensing performance of the WSN is a key consideration. Two design approaches, using greedy and adaptive simulated annealing (ASA) algorithms, are considered in detail. Performance results assuming a grid network in a Rician fading environment are presented for the two design approaches.

宽带无线通信系统环境的电磁处理体系与方法

围绕系统性电磁处理,分析了近年来相关研究工作和进展,提出了基于辐射端点连接面为基准的电磁处理网络架构和基站终端多维辐射体等效辐射模型,以及面向正向电磁利用、反向电磁抑制的电磁互作用分析技术和面向空中电磁特性控制的测试技术等。仿真和测试表明,所提出的多频组网电磁频谱规划突破了多频带及大带宽难题,提高了频谱利用率和复杂环境的主动电磁调控能力;所提出的基本模型及计算方法,突破了受限空间中高效电磁计算预测以及电路天线一体化难点;室外场景重构测试建模提升了精准重现及多场景辐射一致性评估水平。16双极化探头均匀分布、支持4×4的多探头方法被3GPP 5G标准TR 38.827正式采纳。

Solving Dynamic Spectrum Management Problem Based on Cloud Computing Using Genetic Algorithm

With the rapid development of wireless sensor network （WSN）, the demands of limited radio frequency spectrum rise sharply, thereby dealing with the frequency assignment of WSN scientifically and efficiently becomes a popular topic. To improve the frequency utilization rate in WSN, a spectrum management system for WSN combined with cloud computing technology should be considered. From the optimization point of view, the study of dynamic spectrum management can be divided into three kinds of methods, including Nash equilibrium, social utility maximization, and competitive economy equilibrium. In this paper, we propose a genetic algorithm based approach to allocate the power spectrum dynamically. The objective is to maximize the sum of individual Shannon utilities with the background interference and crosstalk consideration. Compared to the approach in [1], the experimental result shows better balance between efficiency and effectiveness of our approach.

基于AT86RF231的无线扩频语音通信方案

随着无线通信技术的发展,适配多种应用场景的短距离无线通信技术应运而生。ZigBee技术是一种近距离、低复杂度、低功耗、低数据速率、低成本的双向无线通信技术。由于传输的时延不固定,ZigBee不适合实时语音通信。为改善时延问题,文章设计了一种以ZigBee芯片AT86RF231为通信芯片的语音对讲系统,使用芯片的MAC层和物理层,通过FPGA控制收发时序,实现了实时无线语音通信,满足了某系统的无线语音通信要求。

基于机器学习的频谱分配算法在无线通信系统中的应用

阐述受频谱资源稀缺、传统方法的限制,设计一种基于机器学习的频谱分配算法,包括数据处理、特征选择与提取、模型训练与优化。实验结果表明,该算法频谱分配性能优于传统方法。

Efficient Performance Analysis of Spectrum Sensing for Cascaded Multihop Network over Nagakami-m Fading Channels

Performance evaluation of spectrum sensing in infrastructure based multihop network is very hard to achieve because of the adverse effects of channel fading. In this paper, performance of a multihop link is studied over Nakagami-m distribution. It provides the exact theoretical methodology for the performance analysis of spectrum sensing by evaluating detection probability. Using a cascaded multihop model, the end-to-end Signal to Noise Ratio (SNR) is given over Nakagami-m distribution. In the analysis, multihop model based on relays are considered over independent and not identically distributed (i.n.i.d) wireless channels. Simulation results show the effect of increase in number of hops on probability of detection for multihop links. Subsequent to the thorough fading severity analysis, it has been accomplished that spectrum hole detection is more crucial at lower SNR values with large number of hops.

基于无线环境地图的星地智能频谱共享方法

卫星和地面组件共享同一频段可以有效缓解频谱稀缺问题,提升频谱利用率,星地频谱共享将在未来的无线系统中发挥至关重要的作用。相较于传统的七色复用星地频谱共享方案均匀地分配点波束带宽,通过波束预测能够基于点波束流量需求的变化合理分配带宽,而频谱预测能够有效降低碰撞概率,从而提升网络频谱效率。提出一种基于无线环境地图的星地智能频谱共享方法,该方法联合波束预测和频谱预测,构建无线环境地图并基于无线环境地图进行频谱分配。仿真结果表明,该方法可有效提升频谱利用率,降低网络阻塞率和用户等待时间。

基于LoRa通信的无线发射台信号智能监测技术研究

为实现大面积无线发射台信号覆盖监测,有效地抵御监测过程中多径干扰和频率选择性衰减等干扰因素的影响,研究基于LoRa通信的无线发射台信号智能监测技术。在无线发射台发出信号后,转换成数字信号进行对比,识别出有效发射台信号后,通过级联型LoRa组网方式以及LoRa通信技术,将数据发送到服务器中存储,实现无线发射台信号的传输。利用循环位移因子对基带产生的Chirp信号完成调频扩频调制,扩展信号频谱,增强信号抗干扰能力以及传输可靠性,增强信号监测的效果。实验结果表明:该方法能够在距离LoRa终端设备2.5 km处依旧接收到发射台信号,丢包率为12%,能够准确地监测到无线发射台是否存在发射信号。

基于二进制正弦余弦算法的频谱分配方法

为解决频谱资源短缺问题,提出一种基于二进制正弦余弦算法(Binary Sine Cosine Algorithm,BSCA)的认知无线电频谱分配方法。在算法中构造非线性振幅调节因子,有助于动态调整迭代期间的搜索步长,提高算法全局搜索能力和收敛精度;利用二进制代码转换公式将正弦余弦算法推广至离散域;将改进后的二进制正弦余弦算法进行频谱分配的仿真实验,并与粒子群优化算法、遗传算法、量子遗传算法作对比,结果表明BSCA具有同时取得较高的网络效益与公平度的优势。

小波域在无线局域网络信号增强中的应用

为提升无线局域网络信号增强中的去噪效果,应用小波域思想,设计一种无线局域网络信号增强算法.针对无线局域网络,收集无线局域网络原始功率谱数据,通过功率谱拟合因子提取信号特征,识别网络信号.对于识别的无线局域网络信号,通过过零率和短时功率提取该信号.基于小波域对无线局域网络信号实施去噪处理,分为二维小波变换、二进剖分、信号重构三个步骤.通过贝叶斯方法,在实施稀疏字典训练的同时,实现无线局域网络信号的增强处理,在训练中结合K-SVD算法,将信号增强过程和稀疏字典学习过程进行迭代和融合.将MATLAB R2019a作为测试设计算法的实验平台,利用计算机开展算法性能测试.测试结果表明:设计算法的无线局域网络信号增强性能良好,同时信号去噪性能较强,说明算法满足设计需求,在完善细节后可以投入实际应用.

地铁通信网络的无线频谱管理和干扰抑制技术

主要探讨地铁通信网络的优化问题,旨在提高通信网络质量并满足乘客需求。深入研究了频谱监测、动态频谱访问、干扰识别与抑制、频谱掩蔽以及干扰消除等关键技术,并通过案例研究展示其应用效果。这些技术的应用有助于推动地铁通信网络的发展,满足日益增长的通信需求。

无线电台中的频谱感知算法应用

随着移动通信的广泛使用,无线电技术的应用也在不断地向前发展,使得有限的频谱资源与人类社会发展的矛盾日益凸显,尤其在无线电台领域,频谱资源就是最重要的战略资源。通过感知空间频谱利用情况,分析系统存在的各类干扰,做到及时有效地利用频谱空洞和规避频率碰撞等干扰,提高电台通信的质量,是无线电台研究的重要课题。基于常规无线电台,提出了一种基于实际工程应用的频谱感知处理算法,通过详细分析算法的处理流程,利用MATLAB软件构造原始数据,在现场可编程逻辑门阵列(Field Programmable Gate Array,FPGA)中进行了算法仿真验证,并对实现过程中的资源进行了有效统计,证明该算法在实现时资源消耗低,计算精度高,能够在实际工程中进行使用。

城市轨道交通无线通信网络的设计与性能优化

文章致力于城市轨道交通无线通信系统的设计与性能优化,专注于同频干扰、无线信号覆盖范围和通信质量等关键方面。通过深入需求分析,提出了适应高密度、高速度移动场景的网络结构和优化方法。在频谱资源管理方面,引入了先进的调制解调技术、信道编码方案及物联网技术,以提高频谱利用效率。同时,针对同频干扰问题,采取有效措施来优化通信质量。在天线系统设计中,详细探讨了定向、全向、组合天线的选择与布局优化,以适应城市环境的多样化场景。综合这些方面的解决方案旨在提升城市轨道交通通信系统的性能,推动智能交通的可持续发展。

基于PVDF传感器和LoRa的远程呼吸监测系统

文中设计一种基于PVDF传感器和LoRa无线通信模块的远程呼吸监测系统,旨在为阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者提供高效、准确的远程监控解决方案。该系统利用PVDF传感器采集呼吸信号,通过放大与滤波电路对其进行处理,并利用LoRa技术实现对处理后的呼吸信号进行远程传输与监测。为扩大远程呼吸监测系统的通信范围,引入一级中继设备,并提出新型的信道资源分配规则和扩频因子分配算法,以提高无线通信信道的利用率,增加病人的支持数量。文中首次提出一级中继设备扩频因子的约束条件和中继设备的替代性指数,以优化远程呼吸监测系统的设计过程。通过呼吸信号采集测试验证文中提出的呼吸信号采集放大电路的功能,根据通信测试验证文中提出的网络结构以及搭建网络结构的方法。测试结果验证了系统的有效性,并展示了其在医疗监控领域的应用潜力。