Cooperative interference power allocation in physical layer security under imperfect time synchronization

In physical layer security,considering imperfect time synchronization,a power allocation scheme was proposed to maximize the system secrecy capacity.By analyzing the residual interference power at the authorized receiver caused by imperfect time synchronization,the optimal power distribution method was given,and the relationship between the optimal interference power and the relative channel quality was discussed.Theory and simulation analysis show that when the synchronization error is small,the synchronization error consumes extra power to reach the preset secrecy capacity,and the interference power increases with its increase.As the synchronization error increases,the secrecy capacity of the system gradually fails to reach the preset target,and may even drop to zero.     

空时协作系统的中断概率分析和功率分配研究

提出了选择中继协议下最小化系统中断概率的最优功率分配方案,并给出了最佳功率分配的闭式解。根据协作节点间是否存在交互信息,分别通过对系统中断概率的分析,推出了高信噪比下中断概率的理论界。基于理论界,在功率受限情况下,通过拉格朗日乘数法,得到最优功率分配的闭合解。仿真结果表明,所推理论界在高信噪比下与仿真值近似相等,最优功率分配点的系统性能也要优于其它功率分配点。     

无线协作Mesh网

异构无线网络的融合是当前无线网络的发展趋势。针对融合过程中遇到的诸如传输模式选择、负载平衡、路由和切换之类的问题,文章提出了一种新的网络融合架构：无线协作Mesh网。该架构基于无线Mesh网的网络结构,并通过协作通信进一步优化其结构、提升其性能。该架构能充分发挥Mesh技术高频谱效率、动态自组织的优点和协作通信高分集增益、高能量效率的优点,可为无线网络融合提供一种有效的解决方案。     

Cellular Controlled Short-Range Communication for Cooperative P2P Networking

This article advocates a novel communication architecture and associated collaborative framework for future wireless communication systems. In contrast to the dominating cellular architecture and the upcoming peer-to-peer architecture, the new approach envisions a cellular controlled short-range communication network among cooperating mobile and wireless devices. The role of the mobile device will change, from being an agnostic entity in respect to the surrounding world to a cognitive device. This cognitive device is capable of being aware of the neighboring devices as well as on the possibility to establish cooperation with them. The novel architecture together with several possible cooperative strategies will bring clear benefits for the network and service providers, mobile device manufacturers and also end users.

基于PDA+LDPC迭代接收机的分布式协作通信策略

针对同步DS-CDMA协作通信系统,本文考虑在转发节点端和基站端使用随机数据联合检测算法(probabilistic data association algorithm,PDA)与LDPC码译码器级联的迭代接收机PDA+LDPC,基于该迭代接收机结构,给出了一种分布式协作通信策略,研究表明,该策略较集中式协作伙伴选择策略和传统的DAF协作通信策略可取得更好的系统性能.     

Analysis of cooperative and competitive spectrum sharing for heterogeneous networks based on differential dynamics model

The heterogeneous networks belonging to different service providers form a coalition system for maximizing the profit, where they may either compete or cooperate with each other. In this paper, we introduce the Lokta–Volterra model, a differential dynamics model, to build the competitive and cooperative mechanisms of heterogeneous networks. It considers the natural growth rate of the network itself and competitive and cooperative effects among networks. Then, according to the ordinary differential principle, the stability of the proposed model and its equilibrium points are analyzed. And finally, system performances are evaluated by Vensim that is used for developing, analyzing, and packaging dynamic feedback models. Analysis and simulation results show that the natural growth rate of the network cannot increase its profit, but effective cooperative mechanism among heterogeneous networks can increase the profit of each network. Copyright © 2013 John Wiley & Sons, Ltd.     

网络编码在无线通信网络中的应用

网络编码是一种可以逼近网络容量传输理论极限的有效方法,在无线网络环境。中有着广泛的应用前景。在无线中继网络中采用网络编码技术,可以使中继节点同时为多个用户转发数据,从而获得较高的转发效率。网络编码在无线中继网络中的典型应用方案包括噪声中继采用置信传播算法实现网络编码,复数域网络编码算法以及信道编码和网络编码联合设计方法,它们均可在获得较高网络吞吐量的同时实现完全分集。在多用户协作通信网络中采用网络编码技术,可获得更高的分集增益以及更低的符号错误概率。     

网络-信道联合编码的DmF协作通信技术

提出了一种采用网络-信道编码的解调前传(DmF)协作通信方案.与译码前传(DF)相比,DmF协作方式在中继处只对信号进行解调而非译码,因此,大大降低了中继节点的复杂度.在由两个用户、一个中继节点和一个基站组成的通信模型中,采用LDPC信道编码与网络编码结合的方式,构造了一种DmF协作传输方式.在基站处,通过构造的H矩阵对来自两用户及中继的信号进行联合译码.仿真结果表明:所给方案的性能优于非协作方式及无网络编码的协作通信方式,随着信噪比的增加这种优势会更加明显;另外,DmF的性能与DF的非常接近,但其设备复杂度却大大降低,因此DmF比DF方式更具实用性.同时,该方案在降低设备复杂度、减少延迟、有效对抗无线信道慢衰落、提高通信性能及频谱利用率等方面都是非常有效的.     

Performance study of hybrid decode–amplify–forward (HDAF) relaying scheme for physical layer security in wireless cooperative network

In this paper, the secrecy performance and power allocation of the signal‐to‐noise ratio‐based hybrid decode–amplify–forward (HDAF) relaying protocol in wireless cooperative network are investigated to get security at physical layer. The performance metrics considered are secrecy rate and intercept probability. The Ergodic secrecy rate is approximated theoretically. The effect of relay and eavesdropper locations on the secrecy performance of the system is analyzed. It is found that maximum secrecy rate is obtained for the relay close‐to‐destination case and minimum for the relay close‐to‐eavesdropper case. Jamming schemes are superior in secrecy rate performance than without jamming schemes. To enhance the secrecy rate further with the optimized relay and jammer powers, invasive weed optimization (IWO) algorithm‐based power allocation is proposed. Here, maximizing the secrecy rate is defined as the cost function for the proposed IWO algorithm‐based power allocation. Comparative study is done over the conventional equal and proposed power allocation schemes for validation. The proposed power allocation scheme proved to be superior. Copyright © 2016 John Wiley & Sons, Ltd.     

一种机会协作重传协议及其性能分析模型研究

 本文基于机会中继协作通信系统的优良特性,改进了传统的多中继ARQ(Automatic Repeat Request)协作分集机制,联合物理层与数据链路层优化了无线频谱与能量的利用率,并且首次提出了采用Markov(马尔可夫)吸收链方法的端到端性能分析模型.在此分析模型的基础上,对本文改进的机会协作重传协议进行了端到端成功传输概率、丢包率、时延、吞吐量等性能参数的数值分析,最后用仿真实验对此模型进行了验证,详细讨论了最大重传次数、信道衰落参数、总发送功率等对性能的影响.结果表明,本文改进的机会协作重传协议在节能、抗信道衰落方面,表现出了比直接重传协议和传统的多中继协作重传协议具有更优越的性能.