基于WBOA的3D-DV-Hop节点定位算法

针对三维(3D)-DV-Hop定位算法未知节点从最近的锚节点获取平均跳距估算距离时定位精度低的问题,提出了一种新的基于WBOA的3D-DV-Hop算法。首先,该算法去除了网络中无法通信和无法定位的节点;然后添加了修正因子,修正平均跳距。接着创建一个用于优化的蝴蝶初始种群,构建目标函数。采用自适应权重来平衡全局搜索与局部搜索的能力,使得算法不易陷入局部最优,加快了算法的收敛精度;最终求得全局最优平均跳距。仿真结果表明:尽管算法的平均运行时间略有增加,但算法的定位精度得到了有效提高。

多策略改进的蜣螂搜索算法优化3DDV-Hop节点定位

为了提升传统3DDV-Hop算法的定位精度和稳定性,提出了MIDBO-3DDV-Hop算法。该算法利用多策略改进蜣螂搜索算法(multi strategy improvement dung beetle optimizer, MIDBO)来提高3DDV-Hop算法的定位精度。该算法通过通信半径分级方法细化跳数,使用加权平均跳距来修正节点之间的跳距误差。MIDBO算法引入立方混沌初始化和反向折射机制来初始化算法种群,采用变螺旋策略增强全局搜索能力。算法还融入Levy飞行策略和自适应权重因子,以避免陷入局部最优,并平衡算法的收敛性和搜索多样性。通过MIDBO算法对3DDV-Hop算法中未知节点位置进行优化。仿真结果显示,与传统的3DDV-Hop、IPSO-3DDV-Hop和IGA-3DDV-Hop算法相比,MIDBO-3DDV-Hop算法在定位精度、稳定性和收敛速度方面均达到最优水平。

Secure Wireless Multicasting through Nakagami-m Fading Channels with Multi-Hop Relaying

The additional diversity gain provided by the relays improves the secrecy capacity of communications system significantly. The multiple hops in the relaying system is an important technique to improve this diversity gain. The development of an analytical mathematical model of ensuring security in multicasting through fading channels incorporating this benefit of multi-hop relaying is still an open problem. Motivated by this issue, this paper considers a secure wireless multicasting scenario employing multi-hop relaying technique over frequency selective Nakagami-m fading channel and develops an analytical mathematical model to ensure the security against multiple eavesdroppers. This mathematical model has been developed based on the closed-form analytical expressions of the probability of non-zero secrecy multicast capacity (PNSMC) and the secure outage probability for multicasting (SOPM) to ensure the security in the presence of multiple eavesdroppers. Moreover, the effects of the fading parameter of multicast channel, the number of hops and eavesdropper are investigated. The results show that the security in multicasting through Nakagami-m fading channel with multi-hop relaying system is more sensitive to the number of hops and eavesdroppers. The fading of multicast channel helps to improve the secrecy multicast capacity and is not the enemy of security in multicasting.

基于分类平均跳距的无线传感器网络节点CADV-Hop定位方法

针对原型DV-Hop定位算法中平均跳距的计算产生较大定位误差的问题,提出了一种分类平均跳距的CADV-Hop算法。首先,揭示了无线传感网络中不同跳数路径的单跳距离分布不一致的现象,并分析了这种差异出现的原因与规律。其次,按照跳数对信标间路径分类再计算各类路径平均跳距的分类平均跳距。最后,在分类平均跳距所提供未知节点与最近信标节点之间更精确距离估计的基础上,结合加权最小二乘法最终实现节点坐标解算。仿真实验表明,CADV-Hop算法在不增加算法复杂度以及额外硬件的情况下有效地降低了定位误差,随着信标节点数量增加,CADV-Hop算法比原型DV-Hop算法和两种改进的DV-Hop算法具有更高的定位精度。

基于多应用场景的改进DV-Hop定位模型

针对距离矢量跳(DV-Hop)定位模型定位精度低、优化策略场景依赖性强的问题,提出一种基于函数分析和模拟定参的改进DV-Hop模型——函数修正距离矢量跳(FuncDV-Hop)定位模型。首先,分析DV-Hop模型的平均跳距、距离估计和最小二乘法中的误差原因,引入待定系数优化、阶跃函数分段实验、带等效点的权重函数策略和极大似然估计修正;其次,考虑多应用场景,用控制变量法,分别将总节点数、信标节点比例、通信半径、信标节点数和待测节点数作为变量,设计对照实验;最后,进行仿真定参和整合优化测试两阶段实验,最终的改进策略较原DV-Hop模型的定位精度提高了23.70%~75.76%,平均优化率57.23%。实验结果表明,FuncDV-Hop模型的优化率最高达到了50.73%,与基于遗传算法和神经动力学改进的DV-Hop模型相比,FuncDV-Hop模型的优化率提升了0.55%~18.77%。所提模型不引入其他参量,不增加无线传感器网络(WSN)的协议开销,且有效提高定位精度。

A Synchronization Acquisition Algorithm Based on the Frequency Hopping Pulses Combining

As modern electromagnetic environments are more and more complex,the anti-interference performance of the synchronization acquisition is becoming vital in wireless communications.With the rapid development of the digital signal processing technologies,some synchronization acquisition algorithms for hybrid direct-sequence(DS)/frequency hopping(FH)spread spectrum communications have been proposed.However,these algorithms do not focus on the analysis and the design of the synchronization acquisition under typical interferences.In this paper,a synchronization acquisition algorithm based on the frequency hopping pulses combining(FHPC)is proposed.Specifically,the proposed algorithm is composed of two modules:an adaptive interference suppression(IS)module and an adaptive combining decision module.The adaptive IS module mitigates the effect of the interfered samples in the time-domain or the frequencydomain,and the adaptive combining decision module can utilize each frequency hopping pulse to construct an anti-interference decision metric and generate an adaptive acquisition decision threshold to complete the acquisition.Theory and simulation demonstrate that the proposed algorithm significantly enhances the antiinterference and anti-noise performances of the synchronization acquisition for hybrid DS/FH communications.

Gigahertz frequency hopping in an optical phase-locked loop for Raman lasers

Raman lasers are essential in atomic physics,and the development of portable devices has posed requirements for time-division multiplexing of Raman lasers.We demonstrate an innovative gigahertz frequency hopping approach of a slave Raman laser within an optical phase-locked loop(OPLL),which finds practical application in an atomic gravimeter,where the OPLL frequently switches between near-resonance lasers and significantly detuned Raman lasers.The method merges the advantages of rapid and extensive frequency hopping with the OPLL’s inherent low phase noise,and exhibits a versatile range of applications in compact laser systems,promising advancements in portable instruments.

Quantum correlations and entanglement in coupled optomechanical resonators with photon hopping via Gaussian interferometric power analysis

Quantum correlations that surpass entanglement are of great importance in the realms of quantum information processing and quantum computation.Essentially,for quantum systems prepared in pure states,it is difficult to differentiate between quantum entanglement and quantum correlation.Nonetheless,this indistinguishability is no longer holds for mixed states.To contribute to a better understanding of this differentiation,we have explored a simple model for both generating and measuring these quantum correlations.Our study concerns two macroscopic mechanical resonators placed in separate Fabry–Pérot cavities,coupled through the photon hopping process.this system offers a comprehensively way to investigate and quantify quantum correlations beyond entanglement between these mechanical modes.The key ingredient in analyzing quantum correlation in this system is the global covariance matrix.It forms the basis for computing two essential metrics:the logarithmic negativity(E_(N)^(m))and the Gaussian interferometric power(P_(G)^(m)).These metrics provide the tools to measure the degree of quantum entanglement and quantum correlations,respectively.Our study reveals that the Gaussian interferometric power(P_(G)^(m))proves to be a more suitable metric for characterizing quantum correlations among the mechanical modes in an optomechanical quantum system,particularly in scenarios featuring resilient photon hopping.

Moisture‑Electric–Moisture‑Sensitive Heterostructure Triggered Proton Hopping for Quality‑Enhancing Moist‑Electric Generator

Moisture-enabled electricity(ME)is a method of converting the potential energy of water in the external environment into electrical energy through the interaction of functional materials with water molecules and can be directly applied to energy harvesting and signal expression.However,ME can be unreliable in numerous applications due to its sluggish response to moisture,thus sacrificing the value of fast energy harvesting and highly accurate information representation.Here,by constructing a moisture-electric-moisture-sensitive(ME-MS)heterostructure,we develop an efficient ME generator with ultra-fast electric response to moisture achieved by triggering Grotthuss protons hopping in the sensitized ZnO,which modulates the heterostructure built-in interfacial potential,enables quick response(0.435 s),an unprecedented ultra-fast response rate of 972.4 mV s^(−1),and a durable electrical signal output for 8 h without any attenuation.Our research provides an efficient way to generate electricity and important insight for a deeper understanding of the mechanisms of moisture-generated carrier migration in ME generator,which has a more comprehensive working scene and can serve as a typical model for human health monitoring and smart medical electronics design.

基于模拟退火和樽海鞘群优化的DV-Hop定位算法

针对无线传感器网络(WSNs)中传统DV-Hop算法定位误差较大等问题,提出基于模拟退火和樽海鞘群优化的DV-Hop定位算法。该算法分别引入RSSI和修正因子来量化最小跳数以及校正平均跳距,在未知节点估计过程中,采用改进的樽海鞘群优化算法代替最小二乘法,并且与模拟退火算法相结合,缓解了樽海鞘群优化算法在寻优过程中容易陷入局部最优的缺点。仿真结果表明:改进后的DV-Hop算法相比于传统DV-Hop定位算法以及其他智能优化算法,定位精度得到明显改善。

基于改进麻雀搜索算法的3DDV-Hop定位算法

针对经典3DDV-Hop算法定位精度不高的问题,提出一种基于改进麻雀搜索算法优化的改进的3DDV-Hop算法;算法首先通过多通信半径优化传感器节点之间跳数,并且在平均跳距计算过程中引入动态加权因子提高平均跳距计算精度,其次在麻雀搜索算法的基础上融合反向学习策略与萤火虫算法分别对麻雀搜索算法的种群与位置更新迭代进行优化,最后将未知节点坐标计算问题转化成改进后的麻雀搜索算法寻优问题,利用改进后的麻雀搜索算法替代最小二乘法计算未知节点坐标,进一步提高未知节点位置计算精度;经过MATLAB仿真验证,改进算法对比于经典3DDV-Hop算法和相关算法,定位精度得到有效提高。

无线传感器网络DV-Hop定位算法的改进

在无线传感器网络中,节点定位占有极其重要的一席之地。无需测距方案中的DV-Hop算法因其计算简单易于实现得到广泛应用。传统DV-Hop算法不能够提供相对好的定位精度,为了保证定位的准确性,文章对DV-Hop算法进行了优化。在优化算法中,采用加权误差修正锚节点的估计平均跳距使其更加接近实际值,之后采用二维双曲线算法代替三边法或最小二乘算法确定接近实际位置的待测节点坐标。仿真结果验证了文章提出算法在无线传感器网络中定位的准确性。

基于螺旋更新策略蜜獾优化的DV-Hop定位算法

节点定位是无线传感器网络(Wireless Sensor Networks,WSNs)的关键技术之一。针对传统距离向量跳段(Distance Vector Hop,DV-Hop)算法定位误差偏大的问题,提出了一种改进蜜獾算法(Honey Badger Algorithm,HBA)与DV-Hop相结合的算法。首先,针对网络平均跳距估计不准的问题,依据锚节点比例对未知节点平均跳距进行分段修正。其次,采用改进型的HBA替换最小二乘法估算未知节点的位置,进一步降低计算误差。初始化蜜獾个体时引入Sobol序列,增加初始种群的多样性;为了加强HBA的局部搜索能力,引入了螺旋更新策略。最后,采用镜像策略规避估算位置越界的情况。结果表明,所提算法相较于传统DV-Hop算法、平均跳距修正的DV-Hop算法和基于粒子群优化(Particle Swarm Optimization,POS)的DV-Hop算法具有更高的定位精度和稳健性。

Multi-hop teleportation based on W state and EPR pairs

Multi-hop teleportation has significant value due to long-distance delivery of quantum information. Many studies about multi-hop teleportation are based on Bell pairs, partially entangled pairs or W state. The possibility of multi-hop teleportation constituted by partially entangled pairs relates to the number of nodes. The possibility of multi-hop teleportation constituted by double W states is （4/9）~n after n-hop teleportation. In this paper, a multi-hop teleportation scheme based on W state and EPR pairs is presented and proved. The successful possibility of quantum information transmitted hop by hop through intermediate nodes is deduced. The possibility of successful transmission is （2/3）~n after n-hop teleportation.

海量文献数据无线传感DV-Hop定位算法设计

现有的数据无线传感定位算法无法获取锚节点与待定位节点之间的最小跳数,导致定位偏差较大,且可应用的网络环境单一。针对海量文献数据,设计新的无线传感DV-Hop定位算法。利用文献数据位置信息表获取锚节点至待定位文献数据未知节点的最小跳数,利用所确定的最小跳数确定无线传感器网络中每跳的平均距离,选取极大似然估计法利用每跳的平均距离确定待定位未知节点的定位结果。通过修正锚节点间跳数、修正未知节点跳数以及修正未知节点平均跳距三部分优化DV-Hop定位算法,提升海量文献数据定位精度。实验结果表明,修正系数为2.05时,文献数据定位精度较高;定位精度伴随锚节点覆盖率的提升有所降低;不同网络场景时,所研究算法的定位精度均高于0.94。

Physical Layer Security of Multi-hop Aided Downlink MIMO heterogeneous Cellular Networks

This study investigates physical layer security in downlink multipleinput multiple-output(MIMO) multi-hop heterogeneous cellular networks(MHCNs),in which communication between mobile users and base stations(BSs) is established by a single or multiple hops,to address the problem of insufficient security performance of MIMO heterogeneous cellular networks.First,two-dimensional homogeneous Poisson point processes(HPPPs) are utilized to model the locations of K-tier BSs in MIMO MHCNs and receivers,including those of legitimate users and eavesdroppers.Second,based on the channel gain distribution and the statistics property of HPPP,the achievable ergodic rates of the main and eavesdropper channels in direct and ad hoc links are derived,respectively.Third,the secrecy coverage probability and the achievable ergodic secrecy throughput of downlink MIMO MHCNs are explored,and their expressions are derived.Lastly,the correctness of the theoretical derivation is verified through Monte Carlo simulations.

Multi-Hop Free Space Optical Communications Using Serial Decode-and-Forward Relay Transmissions

This paper investigates the performance of multi-hop Free Space Optical(FSO) communications using serial Decode-and-Forward(DF) relay transmissions.A statistical model for the optical intensity fluctuation at the receiver due to the combined effects of atmospheric turbulence-induced fading,mis alignment fading and pass-loss is presented.Under given weather and mis alignment conditions,a closed-form analytical expression for the end-to-end outage probability of serial Decode-and-Forward(DF) multi-hop FSO communications is derived.Numerical results show that the serial DF multi-hop transmission is a promising technology to enhance the performance of FSO communications.Moreover,the derived analytical expression can provide close approximations to the simulation results.

Anti-follower jamming wide gap multi-pattern frequency hopping communication method

This paper deals with the follower jamming(FJ)resistance for the frequency hopping(FH)communication system over additive white Gaussian noise(AWGN)channel.Conventional FH systems are susceptible to be jammed by FJ,and multi-pattern frequency hopping(MPFH)has good resistance to FJ.To further improve the FJ rejection capability of MPFH,we propose a wide gap multi-pattern frequency hopping(WGMPFH)scheme.WGMPFH uses channels to represent messages,and the data channel and complementary channel are hopping on orthogonal frequency slots according to wide gap FH patterns.The transmitted signal lures FJ to aim at the data channel and the complementary channel is away from FJ by adopting wide gap frequency patterns.FJ does not affect the complementary channel but increases the signal energy in the data channel,thus the effect of FJ is reduced.Its bit error rate(BER)is derived under FJ and the effects of three FJ parameters(tracking success probability,jamming duration ratio and jamming bandwidth ratio)on the BER performance of WGMPFH are investigated versus the co nventional FH/BFSK and MPFH system.Numerical and simulation results show that when under the worst-case FJ,the proposed WGMPFH outperforms the MPFH by about 1-3 dB and outperforms the conventional FH/BFSK by more than 4 dB.The proposed WGMPFH shows superior jamming rejection performance under FJ especially in severe signal-to-jamming ratio(SJR).

DV-Hop定位算法的混沌粒子群优化

针对距离矢量跳距(Distance Vector Hop,DV-Hop)定位算法通信半径选择不合理导致平均跳距和定位误差较大的问题,提出一种基于混沌粒子群改进的DV-Hop定位算法,利用混沌映射的遍历性和随机性实现粒子的局部深度搜索,避免粒子群算法陷入局部最优。通过混沌粒子群优化(Particle Swarm Optimization,PSO)算法迭代求解所有信标节点的通信半径,引入混沌理论调整非线性惯性权重优化搜索过程,通过混沌搜索和混沌扰动迭代求解信标节点的最佳通信半径;通过极大似然估计(Maximum Likelihood Estimate,MLE)法计算的平均定位误差作为混沌粒子群算法的适应值函数;使用费希尔矩阵求解的误差下限作为约束条件求解适应值函数,同时把平均通信半径作为节点能耗模型的阈值来降低节点能量消耗。仿真实验表明,提出的算法在不增加算法复杂度的前提下能够在定位精度方面提升近58%,节点能量消耗方面降低近24%。

Multi-user performance analysis of differential frequency hopping system over Rayleigh-fading channel

A novel non-coherent detection scheme for differential frequency hopping(DFH)system is proposedin asynchronous multi-user environments over Rayleigh-fading channels.The synchronous and asyn-chronous multi-user performances of DFH with the conventional detection scheme and this novel detectionscheme are analyzed,respectively.The performance results are validated with simulation.The results ofanalyses and simulations prove two conclusions.Firstly,the performance of asynchronous multi-user DFHsystem overcomes that of synchronous multi-user DFH system over Rayleigh-fading channel.Secondly,the novel detection scheme can achieve better performance than the conventional non-coherent detectionscheme in asynchronous multi-user environments.