C^3I系统时分多址网络仿真平台设计

介绍了Ｃ３Ｉ系统时分多址网络仿真平台的组成、原理、功能及设计思想．该平台的设计可使防空Ｃ３Ｉ系统的硬件与软件开发工作并行进行，从而缩短了整个系统的开发周期．该平台已应用于某地面射击指挥系统的仿真系统中     

SAWTDL在扩频通信中的应用

声表面波器件是扩频通信系统中的理想器件,它可以简化系统,提高系统的抗干扰性能。文中主要介绍声表面波抽头延迟线(SAWTDL)在TDMA扩频移动通信系统中的应用。     

System Capacity and Access Control for Multimedia TDMA/SS Networks

In this paper, we study the system capacity and access control for the TDMA/SS (time division multiple access with spread spectrum) cellular networks supporting multimedia services. In the TDMA/SS system, time is divided into frames and each frame is further divided into slots. Only one user is allowed to transmit in a slot and spread spectrum technique is adopted to combat inter-cell interference. A packet can occupy more than one slot, depending on the user's data rate and quality of service requirement. We derive a necessary and sufficient condition for a group of users to be admissible for the TDMA/SS system and prove that its admission region contains that of the TDMA/CDMA system. In the TDMA/CDMA system, time is also divided into frames and each frame consists of several slots. The difference is that every packet occupies exactly one slot and multiple users can transmit their packets in the same slot. Numerical results show that the admission region of the TDMA/SS system can be significantly larger than that of the TDMA/CDMA system. To further increase bandwidth utilization and guarnatee delay bound requirements, several access control schemes are proposed. Simulation results are obtained for these access control schemes.     

Energy efficient TDMA-based MAC protocol associated with GAF for wireless sensor networks

The design of media access control (MAC) protocol for wireless sensor networks (WSNs) with the idea of cross layer attracts more and more attention. People can improve the MAC protocol by obtaining certain information regarding the network layer and physical layer. This article synthesizes and optimizes certain cross-layer protocols which have existed. On the basis of the routing, topology information in the network layer, and transmission power information in the physical layer, the time slot assignment algorithm has been improved in the MAC layer. By using geographical adaptive fidelity algorithm (GAF) to divide the grids, controlling of transmission power and scheduling the work/sleep duty cycle for sensor nodes, a new MAC protocol has been proposed to decrease energy consumption and enlarge the lifetime of WSNs. Simulation results show that the MAC protocol functions well.     

3G高速数据接入技术研究

本文将证明利用现有的CDMA基本原理很难实现1x EV-DV和HSDPA应该达到的3G高速数据接入的目标,并提出一种利用码分多址/时分多址来改进1x EV-DV和HSDPA系统的方案,它将利用码分多址区分语音和高速数据业务信道,在语音和高速数据业务信道中分别选用码分和时分多址方式。这种方法可改进cdma2000 1x和WCDMA标准上下行容量基本对称的技术问题,使其符合移动因特网的需求。     

TDMA数字移动通信系统无线干扰技术研究

采用TDMA技术体制的数字移动通信系统,其系统架构和工作方式类似,因此对其干扰方式也基本相同。针对军用TDMA数字移动通信系统,以典型的GSM数字移动通信系统为研究对象,对灵巧式和欺骗式干扰技术进行了研究。     

移动水下传感器网络动态TDMA协议

介质访问控制(MAC)问题是水下传感器网络(UWSN)研究的热点问题之一,其协议设计的主要挑战是水下网络的信号传播延迟太高带来冲突的“时空不确定性”现象—来自不同站点的帧是否冲突不仅取决于他们的发送时间,还取决于这两个站点的位置.因此总结了水下MAC协议的最新研究成果,提出了一个基于位图协议的动态水下TDMA协议,适用于节点能够局部运动的动态水下网络.该协议利用水下特殊的“时空不确定性”现象减少信道空闲,提高能量效率和传输效率.最后,通过仿真实验验证了协议的可用性和效率.     

Rate regulated TDMA system for cochannel interference limited wireless ad hoc networks

The time slotted system with rate regulation, which adapts the transmission rate to the interference for each time slot, is proposed to enhance the throughput while meeting the SINR requirement for cochannel interference limited wireless ad hoc networks. We show that the throughput of the rate regulated TDMA system is larger than that of the rate regulated TDMA/CDMA system. Furthermore, we also propose a scheduling algorithm to maximize the total throughput of the rate regulated TDMA system.     

TDMA卫星通信技术在实际中的应用

以一个较成功的案例，探讨了TDMA卫星通信技术在会议电视、数据通信、话音等综合业务中的应用。     

一种低信噪比TDMA信号的载波同步算法

本文深入研究了基于FFT运算进行相位扩展的宽范围自相关函数法和宽范围L&R算法,分析了这两种载波频偏估计算法的性能.在此基础上,本文结合TDMA信号的前导字和CZT(chirp z-transform)算法的高频率分辨率特性,设计了适于低信噪比信号的宽范围载波同步改进算法.该算法利用TDMA信号的前导字进行数据辅助(DA)型载波同步,有效地缩小了低信噪比信号的频偏范围;再利用CZT算法进一步缩小频偏范围,最后利用非数据辅助型(NDA)自相关函数法得到精确的载波频偏.改进算法的计算复杂度略高于宽范围自相关函数法,而远低于宽范围L&R算法.通过仿真比较,改进算法对低信噪比(SNR)环境(3-6dB)中的信号具有良好且稳定的估计性能.