波分多址 的英文怎麼說
中文拼音 [bōfēnduōzhǐ]
波分多址
英文
wdma waveength division mtipe access-
In this paper, after introduction of the code division multiple access ( cdma ) and orthogonal multicarrier ( mc ) technique, the system model of mc - cdma is analyzed and the bit error rate ( ber ) performance in downlink and uplink channel is shown in awgn channel by computer simulation
本文在碼分多址技術和正交多載波技術原理基礎上，分析了高斯白噪聲通道中多載波碼分多址（ mc - cdma ）系統的數學模型，並且使用不同的擴展碼對下行通道和上行通道誤碼率性能分別作了計算機模擬分析。First of all, we bring forward the basic project of tadil, which adapts to combined operations. it is suggested to use tdma ( the abbreviation of time division multiple access ) as the working pattern and utilize the concept of mobile ad hoc network to construct the data link network. aiming at the impact of time delay on data link and the characteristic of cooperative combat under the command of director aircraft, this thesis applies a kind of kalman filtering algorithm in polar coordinates to compensate the error of time delay, and then does the transformation of target motion parameters to obtain the current information of target
本文結合空軍裝備部某「十五」預研課題，圍繞著戰術數據鏈、多機協同多目標攻擊、超機動攻擊、空對地攻擊這四個方面展開了一系列的研究工作:本文首先給出了適應三軍聯合作戰的戰術數據鏈系統的基本方案，建議採用時分多址的工作模式，並利用移動自組織網路的概念構建數據鏈網路，同時針對數據鏈傳輸信息的時間延遲特性和指揮機指揮下的多機協同作戰特點，應用一種極坐標系下的卡爾曼濾波演算法對該傳輸延遲誤差進行補償，並在此基礎上進行目標運動參數的轉換，以獲得目標相對于某無人機的當前運動信息，且利用模擬驗證了方法的有效性。In a tdma network, multiple users share the common medium ( or channel ) and bandwidth but different intervals of time. in case of the burst mode, the carrier of the modulated signal needs to be synchronized in a very short time. the common approaches such as a costas - loop and so on are no longer suitable any more
在一個時分多址（ tdma ）通信網路中，多個用戶通過不同的時間段共享一個傳輸線路（或者通道）的帶寬資源，每個用戶只能在分配給自己的時間段內進行通信，這種突發方式信號的解調要求載波恢復要在很短的時間內完成，我們以往在連續信號解調器中採用的costas環等方法很難適應這種要求。In this thesis, first, we present the theory of sess system, the generation of the sess spreading code and its characteristics and the acquisition theory of conventional spread spectrum communication system. an efficient acquisition scheme based on periodically transmitting the synchronization head, which is composed of binary chaotic codes, using the matched filter and automatic decision threshold - level control based on a so - called constant false alarm criterion for sess system is present. the acquisition model of sess system is built and simulated in the awgn channel, the raleigh fading channel and imulti - address interfere condition
本文首先概述了自編碼擴頻通信的原理、自編碼擴頻序列的產生方法及其特性和擴頻通信系統編碼同步的理論，然後針對自編碼擴頻通信系統提出了擴頻序列捕獲方案:周期性地加入混沌序列同步碼，並採用恆虛警率匹配濾波器捕獲法;在加性白高斯噪聲通道、瑞利衰落通道和多址干擾情況下進行了模擬，分析了各種捕獲性能:在選擇性能最優的混沌序列、適當的序列長度、虛警概率及門限值的情況下，可以獲得較短的捕獲時間和較大的捕獲概率。The medium access control ( mac ) layer protocol of the airlink interface between the mobile data base station ( mdbs ) and mobile end systems ( m - ess ) in cellular digital packet data ( cdpd ) is studied firstly. the access method of slotted non - persistent digital sense multiple access with collision detection ( dsma / cd ) is described mainly
本文首先研究了蜂窩數字分組數據（ cdpd ）空中介面中的介質接入控制層（ mac ）協議，詳細論述了基於時隙的非堅持的、帶沖突檢測的數字載波偵聽多址接入協議（ dsma cd ） 。Uplink space - time channel blind estimation for space - time coded multicarrier code division multiple access systems
空時編碼多載波碼分多址系統上行空時通道盲估計With the trend that cdma will be the dominant multi - access scheme in the new generation of wireless communication, how to apply spatial processing in cdma system has been becoming the emphasis of research in smart antenna. a proper method is space - time processing due to the space - time structure of wireless channel. beamforming can be combined with rake to form 2d rake receiver, which can effectively weaken the enhancement of mai in conventional rake receiver. however a more effective method is to use space - time filtering. these two scheme will be discussed and the structure and realization will be presented
碼分多址技術逐漸成為新一代通信系統的主流多址技術，如何在碼分多址系統中引入空域處理以改善系統性能是當前智能天線技術研究的重點之一.考慮到無線通道的時空二維結構特徵，一種合理的實現方式是採用時空處理方法，將波束形成技術與時域分集技術相結合;另一種更有效的方法是在接收端採用時空二維聯合處理，對無線通道進行時空二維均衡Csma cd information processing systems - local area networks - part 3 : carrier sense multiple access with collision detection csma cd access method and physical layer specifications
信息處理系統局域網第3部分:帶碰撞檢測的載波偵聽多址訪問Csma cd local and metropolitan area networks - specific requirements - part 3 : carrier sense multiple access with collision detection csma cd access method and physical layer specifications
局域網和城域網.特殊要求.第3部分:帶沖突檢測的載波偵聽多址存取A mutirate transmission protocol is proposed, which is based on the csma and implemented rate information exchange, duration setting, nav update and calculating
該協議基於碰撞檢測的載波偵聽多址協議，實現了速率信息交換、預約時長設置和網路分配矢量的更新和計算。Wdma wavelength division multiple access
波分多址Finally, the paper discusses the effect of fiber dispersion and non - linear characteristics on the operation of multi - access systems
著重解釋光纖本身的色散與非線性特性對波分多路波分多址系統運用的影響。Multiuser receiver design for differential - space - time - coded cdma systems
多載波碼分多址系統的上行等效空時多用戶檢測Contributions in this paper mainly sh ow four points : 1 the structure characteristic of the received ds - cdma signal is analyzed in the presence of multi - path slow fading effect case for wireless mobile communication. according to this characteristic, four data - selected schemes based on chip - matched filter are presented from the perspective of energy and structure of signal. and the impact of these schemes on multiple - access interference ( mai ) and inter - symbol interference ( isi ) is analyzed
本文的主要貢獻在於四個方面： 1 、針對無線移動通信系統中廣泛存在多徑慢衰落效應的情況，分析了ds - cdma系統中接收信號本身的結構特徵，根據這個特徵，在匹配濾波的基礎上，從能量與信號結構的角度提出了四種不同的數據採用方案，並分析了不同數據方案對多址干擾與碼間干擾的影響。Now cdma is very mature and becomes the key technique of the third - generation mobile communication systems. more and more attention is paid to the technique of multi - carrier. mc - cdma is combination of ofdm and cdma, thus advantages of both techniques are exploited
近年來移動通信技術發展迅猛，碼分多址技術到目前已經非常成熟，並成為了第三代移動通信系統的核心，人們將眼光聚集在正交頻分復用調制技術，將多載波調制技術應用於cdma中，從而兼具多載波技術和cdma技術的優點。Proposes a novel channel estimation algorithm for multi - carrier code division multiplex access ( mc - cdma ) systems on the uplink
摘要提出了一種新穎的適用於多載波碼分多址接入（ mc - cdma ）系統上行鏈路的通道估計演算法。With the downlink simulation model constructed, performance of wideband cdma under different radio propagation environment and vehicular speed is simulated. based on system model of mc ds cdma under flat fading channel with relative shifts of spreading sequences within 1 chip and frequency selective fading channel with arbitrary relative chip shifts, performance of multicarrier cdma system with go sequences under different radio environment is investigated
基於多載波直接序列碼分多址在乎坦衰落通道中序列偏移小於1個碼片及在頻率選擇性衰落通道中偏移任意個碼片的系統模型，本文還分析了採用廣義正交序列的多載波碼分多址系統在不同無線傳播環境下的性能。The problem of signal processing for direct - sequence code - division - multiple - access ( ds - cdma ) signal over multipath frequency - selective mobile channels is considered. a new blind receiver is proposed. without the knowledge of the multiple - access interference users spreading code and the channel characteristics, the receiver achieves blind detection with prior knowledge of only the desired users spreading code and approximate timing. by using reduced rank adaptive decorrelating filter and adaptive multipath combiner which is based on decision - directed algorithm, the receiver gets the ability to combat both fading and the near - far effect at low cost. simulation results demonstrate that the proposed receiver offers high performance
本文研究多徑頻率選擇性衰落通道下直接序列擴頻碼分多址（ ds - cdma ）信號的處理問題，提出了一種新型的盲接收機.該接收機不需預知多址干擾用戶的擴頻碼，不需預知通道參數，只需已知期望用戶的擴頻碼和粗略的定時，就可以完成用戶的盲檢測.同時，該接收機通過降維自適應去相關濾波和基於判決指導的自適應多徑合併，來獲得低成本和良好的抗衰落、抗遠近效應性能.模擬結果驗證了本文提出的接收機的優良性能Concerning with the direct sequence ( ds ) cdma system, this thesis focuses on several issues related to orthogonal spreading sequences and amc, including correlation properties of orthogonal variable - length spreading sequences and their effects on ds cdma system performance, performance of multicarrier ( mc ) ds cdma system with generalized orthogonal ( go ) sequences, adaptive modulation with throughput maximization, performance of adaptive turbo - qam coded modulation in generalized fading channel and performance of amc in wcdma high speed downlink packet access ( hsdpa )
針對直接序列碼分多址（ dscdma ）系統，本文主要研究了正交擴頻序列和自適應調制編碼若干問題，包括正交變長擴頻序列的相關性及其對dscdma系統性能的影響、採用廣義正交（ go ）序列的多載波直接序列碼分多址（ mcdscdma ）系統性能、吞吐量最大化自適應調制、自適應turbo - qam編碼調制在廣義衰落通道中的性能，以及wcdma下行分組接入（ hsdpa ）中自適應調制與編碼性能五個方面。The researches in this dissertation focus on several key technologies in mt receiving of wideband code division multiple access ( wcdma ) system, including digital matched filter, rake receiver, design method of synchronization and digital shaping filter
本文研究第三代移動通信中的寬帶碼分多址（ wcdma ）系統移動臺（ mt ）接收的若干關鍵技術。包括數字匹配濾波器、 rake接收機、同步電路設計和數字成型濾波器等。分享友人