基于补偿式CSI的分布式跨层联合资源分配算法

为消除过时信道状态信息(CSI)对分布式无线多跳网络环境下跨层资源分配效率的影响,提高跨层联合资源分配的准确性,基于信道相关性提出了一种补偿式跨层联合资源分配算法。利用瞬时和过时信道状态信息之间的条件概率密度函数,基于瑞利衰落信道模型求得信噪比(SINR) 模型下条件容量的闭式解。为补偿部分网络性能的损失,提出了一种考虑过时信道状态信息的联合拥塞控制、信道分配和功率控制的算法,在此过程中网络被建模成一个NUM 问题,可变的链路数据率和功率等资源限制作为约束条件。运用拉格朗日对偶分解技术,NUM问题被分布式求解。实验对比分析表明：在确保较低复杂度的前提下,该算法有效改善了分布式多跳网络资源分配的合理性,使其网络总体效用得到提升,降低了能耗。     

“数字通信”课程中信道解析的教学探讨

本文以“数字通信”课程中的难点：信道解析为例,融入“线性代数”和“信号处理”等相关课程的知识内容,设计了一种递进式探究教学方法和课程实践方案。并以推导互扰条件下的信道分解公式为例,来完成探究式课程内容的学习与互动。教学实践表明,该方法能针对本学科特点,提高教学质量。     

A Double Auction Mechanism for Heterogeneous Multi-unit Spectrum Trading

The last decade has witnessed a rapid growth in wireless communications technology,and as a result the demand for spectrum resources increased rapidly.Unfortunately,many new wireless demanders cannot access the limited wireless licenses in time while large chunks of spectrum are idle.To solve this,we design a multiunit double auction mechanism for heterogeneous spectrum channels,which take the spatial and temporal reuse into consideration.The proposed scheme first introduces the multi-participants multi-heterogeneous-spectrum trading double auction to illustrate the system model.Some techniques such as spectrum categorize,virtual sellers and buyers' conflict graph construction,and reconstruction of buyer groups are adopted to achieve a high efficiency of the algorithm.Then,we also prove the truthfulness,individual rationality,and budget balance of the proposed scheme.Finally,the simulation results show that the practical performance of the proposed scheme can efficiently improve the spectrum transaction ratio,reuse ratio,and the buyer's satisfactory ratio.     

基于信用管理的海事公共服务平台研究及应用

目前政府公共服务以信息查询服务为主,而业务申请和办理类的公共服务受制于身份认证和有效性确认等问题还处于线上和线下并行的方式进行处理。本文针对互联网服务的特征,结合信用管理体系和可信的基础数据的应用,构建一个包括互联网、移动互联网、微信、短信等多种服务手段在内的海事公共服务平台,实现业务的全网络化的办理。针对互联网应用的特征,设计适合于互联网应用的海事公共服务的体系,能够充分的发挥已有信息化建设成果的效益,真正的实现优质高效的社会服务。     

Generalized Balanced Tournament Packings and Optimal Equitable Symbol Weight Codes for Power Line Communications

Generalized balanced tournament packings (GBTPs) extend the concept of generalized balanced tournament designs introduced by Lamken and Vanstone (1989). In this paper, we establish the connection between GBTPs and a class of codes called equitable symbol weight codes (ESWCs). The latter were recently demonstrated to optimize the performance against narrowband noise in a general coded modulation scheme for power line communications. By constructing classes of GBTPs, we establish infinite families of optimal ESWCs with code lengths greater than alphabet size and whose narrowband noise error‐correcting capability to code length ratios do not diminish to zero as the length grows.     

Fairness-aware resource allocation for D2D-enabled IoT in NOMA-based cellular networks with mutual successive interference cancellation

Device-to-device (D2D) communications and non-orthogonal multiple access (NOMA) are promising technologies to meet the growing demand for IoT-connected devices. However, they bring about new challenges including the co-channel interference, that can limit the performance improvement. To manage the co-channel interference, we address the problem of joint power allocation and sub-channel assignment for D2D-enabled IoT devices (IoTDs) underlaying a NOMA-based cellular network, in which the successive interference cancellation (SIC) decoding is enabled at the level of IoTDs and cellular user equipment (CUE)to increase the number of connected devices and the capacity. This problem is modeled as a mixed-integer nonconvex optimization problem which includes the concept of fairness with respect to the data rates of IoTDs. To solve the problem, a semi-distributed algorithm is developed, which is of polynomial time complexity. The proposed algorithm leverages the successive convex approximation and a heuristic approach. Evaluation results demonstrate the efficiency of the proposed scheme with respect to the sum rate, fairness, access rate and computational complexity.     

海上无线通信虚拟仿真实训平台建设研究

为应对新冠疫情对实验教学的影响，并解决海上无线通信教学中存在海试实验危险性大、费用高、周期长等实际问题，本文将虚拟仿真技术融入实验实践教学，突破实验教学受地域环境、实验设备和安全因素等限制的局限性，设计了一种海上无线通信虚拟仿真实训平台。首先，本文阐述了平台建设目标与特色。其次，以“认知实验—典型系统实验—综合场景实验”为主线，详细介绍平台的功能模块。学生可从海上通信设备操作、海上通信系统设计和海上通信组网仿真进行实验实践。之后，本文介绍了基于3ds Max和Unity 3D相结合的平台开发关键技术。最后，本文分别介绍了三大实验模块的应用案例。该平台涵盖了海上无线通信学科相关课程实验，将为海洋信息人才的实践能力培养发挥积极作用。     

Effect of realistic sea surface movements in achieving full‐view coverage camera sensor network

In stationary camera sensor networks (CSNs), when the deployment characteristics and sensing models are defined, the coverage can be deduced and remain unchanged over time. However, in the maritime environment, the rough and random sea condition can move CSN from the initial location. We envisage that camera sensors are mounted on quasi‐mobile platforms such as buoys. Hence, it is important to understand the effect of realistic sea surface movements in achieving full‐view coverage because in full‐view coverage, target's facing direction is taken into account to judge whether a target is guaranteed to be captured because image shot at the frontal viewpoint of a given target considerably increases the possibility to detect and recognize the target. To accurately emulate the maritime environment, the movement of the buoy, which is attached with a cable that is nailed at the sea floor, has been characterized based on the sea wave that is created by the wind, and it is limited by the cable. The average percentage of full‐view coverage has been evaluated based on different parameters such as equilateral triangle grid length, sensing radius of camera, wind speed and wave height. Furthermore, a method to improve the target detection and recognition has been proposed in the presence of poor link quality using cooperative transmission with low power consumption. In some parameter scenario, the cooperative transmission method has achieved around 70% improvement in the average percentage of full‐view coverage of a given target and total reduction of around 13% for the total transmission power P_Total(Q). Copyright © 2015 John Wiley & Sons, Ltd.     

On the design of a multi-carrier correlation delay-shift keying system

This paper presents the design of a multi-carrier correlation delay-shift keying (MC-CDSK) system for the operation in wireless environments. In the proposed system, the sum of a chaotic sequence and it delayed version is considered to be a reference sequence and transmitted through a predefined subcarrier. The input data is divided into multiple pairs of bit sub-sequences, where the first and second ones of each pair are spread in the frequency domain by directly multiplying with the chaotic sequence and the delayed version, respectively. The sum of two resulting signals for each pair is then transmitted on a corresponding subcarrier. In the receiving side, the reference sequence retrieved from the predefined subcarrier and the signal retrieved from each of the remaining subcarriers are correlated with the delayed version of the other ones to recover the corresponding bit sub-sequence pair. The recovered pairs are combined to an output data. Schemes for the transmitter and receiver are designed and their operation over a multipath Rayleigh fading channel is described. The system performance is evaluated via theoretical analysis and then verified by numerical simulation. Our findings show that MC-CDSK system can improve communication features, i.e., bit error rate (BER) performance, energy and spectrum efficiency compared to those of the conventional CDSK.     

宽带网络的发展及小区网络工程建设的探讨

本描述了宽带网络的发展趋势和业务需求特点，并针对大客户及住宅小区的通信改造提出了组网方案。