時分碼分多址 的英文怎麼說

中文拼音 [shífēnmǎfēnduōzhǐ]
時分碼分多址 英文
td-cdma time division-code division multiple access
  • 時 : shí］Ⅰ名1 （比較長的一段時間）time; times; days:當時at that time; in those days; 古時 ancient tim...
  • 分 : 分Ⅰ名詞1. （成分） component 2. （職責和權利的限度） what is within one's duty or rights Ⅱ同 「份」Ⅲ動詞[書面語] （料想） judge
  • 碼 : Ⅰ名詞（表示數目的符號或用具） a sign or object indicating number; code Ⅱ量詞1 （指一件事或一類的...
  • 址 : 名詞（建築物的位置; 地基） location; site; ground; foundation
  • 時分 : 時分time:黃昏時分 at dusk; at twiligh; cock-shut time
  1. Traditional multiuser detector make good use of all signals which resuilt in multiple access interference so that it provides optimum mai resistance. ( 1 ) nevertheless, it assumes that the receiver can acquire the signature waveform and timing of desired user and the interfering users ; ( 2 ) it has no ability to suppress intercell multiple access interference ; ( 3 ) it cannot be applied in downlink channels. adaptive multiuser detector eliminates the need to know the signature waveforms and the timing of the interferes and has to need training data sequences for every active user

    傳統多用戶檢測在單用戶檢測技術基礎上，充分利用造成多址干擾的所有用戶的信息進行聯合檢測，從而具有良好的抗多址干擾能力，但存在一些缺陷： （ 1 ）不僅要求知道期望用戶的地址pn碼及其定時信息，還要求其他干擾用戶的地址pn碼及其定時信息； （ 2 ）不能消除其他相鄰小區的多址干擾對本小區的影響； （ 3 ）不能直接應用在cdma移動通信系統中的下行鏈路。
  2. 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。
  3. 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
  4. Evm measurement algorithm for td - scdma ue conformance test based on iterative process

    基於迭代的時分同步碼分多址系統終端誤差矢量值一致性測試演算法
  5. 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
  6. By using the de - interleaving memory combined with memory address computation for the interleaved data, frequency de - interleaving, block de - interleaving and time de - interleaving are performed in one - stage approach in the cofdm receiver

    藉由利用反交錯記憶體結合對該記憶體存取位址的計算，頻域反交錯、區塊反交錯與時域反交錯在正交編碼分頻多工接收器中以單一階段技術來執行。
  7. A cascade structure of space - time multiuser detector in cdma systems

    空時分層結構碼分多址系統的上行多用戶檢測
  8. Then we introduce pulse position modulation ( ppm ) using pn code and analysis its multi - access performance, system capacity and power spectrum density. on the basis of those analyses, we study the pulse shape and the anti - jamming ability of the system. at last, multiple access with pseudochaotic time hopping is introduce

    本文首先闡述了uwb脈沖通信系統的基本原理，重點介紹了用偽隨機碼跳時的ppm （脈沖位置調制）調制，分析了他的多址性能、系統容量和功率譜密度，在此基礎上研究了改進性能的發射信號形狀和系統抗干擾能力，最後介紹了偽混沌碼跳時的多址方式。
  9. 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
  10. Conventional detector ( single - user matched filter ) distinguishes each user by the crosscorrelation of their spread - spectrum codes. in practice, however, its performance is much deteriorated due to the existence of noise in channel and strong multi - access interference, i. e. near for effect. a new method using independent component analysis is proposed in this paper. the - received energy of signals is controlled effectively, thus the near - far effect is overcome as much as possible ; moreover, the effect that noise imposed on the detector is mostly reduced. simulations verify the effectiveness of this method

    傳統檢測器（單用戶匹配濾波）利用擴頻碼之間的互相關特性來區分各用戶信號.而在實際應用中，通道噪聲和近距離用戶對遠距離用戶的強多址干擾即遠近效應，使得接收機的性能受到很大影響.本文將獨立分量分析法引入傳統接收機，有效控制接收信號的能量，從而極大地提高了接收機的抗遠近性能，同時噪聲的影響被盡可能消除.模擬結果表明了該方法的有效性和可行性
  11. Owing to its proximity to the mainland, coupled with tariffs - free arrangement under cepa, hong kong manufactures have gained a head - start in entering the mainland market. moreover, the mainland is developing its own standards such as avs, wapi, td - scdma, and hdtv standards

    此外，內地正訂立多項國家標準，例如數字音視頻編解碼技術標準（ avs ） 、無線局域網加密標準（ wapi ） 、時分同步碼分多址接入標準（ td - scdma ）及高清晰度電視標準（ hdtv ）等。
  12. Since most of the 3g systems are evolved from different incompatible 2g systems like cdma code division multiple access, gsm global system for mobile communication and tdma time division multiple access, therefore the imt - 2000 standard will ensure the compatibility and interoperability of different systems in 3g. 3g is broadband and packet - based

    由於大部份3g系統是由多種不能兼容的2g系統，如碼分多址code division multiple access ，簡稱cdma ， gsm及時分多址time division multiple access ，簡稱tdma制式演進過來的，因此， imt - 2000標準是要保證3g系統所包含的各種程式的兼容及互用性。
  13. Civil air defense alarm system was a system to dispense antiaircraft alarm sig - nal, hand hostile air attack informational communication to urbanite at wartime. it is a particular informational communication system of the civil air defense depart - ment, and can not be taken place. at the development trend of digitaliza - tion, unitization, integration of civil air defense communication, the civil air defense alarm system is developing too, for adaptation to the require of both future war and peaceful dual, and enhancing civil air defense communication system ' s directing automation. in recent years, development of different kinds of communication technology infuses new clearly energy into communication, especially spread spectrum communication, because of its strongly interference - free feature, invisibility best, realizable code division multiple access and antimultipath wane and so on merit, gets extensive use at wireless region ; the corresponding spread spectrum chips emerge as the times and get boom, which provides advantag e to realization of the circuit of spread spectrum communication. at the same time, in company with the advance of electronics level, the single chip microcomputer has a great development, world renowned chip manufacturer pushout respective products one after another, the kinds of which are too many to statiste

    在人防通信的數字化、一體化、綜合化必然的發展趨勢下，人防警報系統也不斷發展，以適應未來戰爭和和平時期的雙重需要，提高人防通信系統指揮自動化。近年來，各種通信技術的發展給通信注入了活力，擴頻通信更因其抗干擾能力強、隱蔽性好、可實現碼分多址和抗多徑衰落等優點在無線領域得到了廣泛應用；其相應擴頻處理晶元應運而生並得到迅速發展，這為擴頻通信的電路實現提供便利。同時隨著微電子工藝水平的提高，單片微型計算機有了飛躍發展，世界上著名的集成電路晶元製造商紛紛推出各自的產品，單片機型號之多，已達到難以統計的地步。
  14. It inherits the anti - multipath fading ability of ofdm technology as well as the high user capacity of cdma. however, the ofdm - cdma system is vulnerable to channel estimation errors in fast varying channels

    但是在快速時變通道中，正交頻分復用碼分多址系統對于通道估計誤差很敏感。
  15. Optical code division multiple access ( ocdma ) is a communication mode which introduces the code division multiple access ( cdma ) technology into optical fiber communication system. besides providing asynchronous communications access, ocdma system has many advantages, such as high capacity, security against interception, suppression of narrow band disturbances, capability in forming variable bit rate networks and multi - rate networks. it implies a great challenge for the development of future communication networks, especially all optical networks

    光碼分多址（ ocdma ）是將碼分多址（ cdma ）技術與大容量的光纖通信技術相結合的一種通信方式，其主要優點表現在如下幾個方面：允許多個用戶隨機地接入同一通道：可構成真正「透明」的全光通信網路；具有良好的安全性；允許可變速率或多速率傳輸，並可同時提供多種業務支持；具有優良好的抗干擾能力，並能夠充分地利用石英光纖的可用帶寬。
  16. Assigning serial different address code to different subscribers, useful signal is taken out of the same time slot and frequence, and is transmitted with one share channel. at received end, system makes use of completed address code from sending end to do correlative check and take out useful subscriber signal. the other address code signals are treated as broadband disturbing signal which is removed. in radio environment of existing variable disturbtion and muti - way declining, expand frequence signal ’ s broadband characteristics can improve system performance obviously. cdma mobile telecommunication system has some better characteristics, such as anti - disturbing 、 anti - way declining 、 secrecy 、 capacity 、 utilizing rate of frequence resource and so on, than other mobile telecommunication system

    Cdma （ codedivisionmultipleaccess ）移動通信系統的技術基礎是基於擴頻技術的碼分多址，通過給不同的用戶分配各自特定的地址碼序列，將處于相同時隙和頻率的用戶信號分離開來，採用共享通道方式傳輸信息。在接收端，系統利用與發送端完全一致的本地地址碼對接收信號進行相關檢測，提取需要的用戶信號，而將其他使用不同碼型的信號視為寬帶干擾而從中剔除掉。
  17. When we carry through the theoretic analysis, according to the request of cdma communication system for spreading code, we analyze the characteristics of chaotic spreading sequence

    在進行理論分析時，根據碼分多址通信系統對擴頻碼的要求，分析了混沌數字擴頻序列的特性。
  18. For power control of listening users, forward power control method are introduced based on full, multichannel, filtered report, and collision method etc. the full report method has redundancy report information, and its real - time performance is bad, multichannel report is introduced to improve the real - time performance, and filtered report is introduced to eliminate the redundancy information, finally the collision method introduced can not only get higher real - time performance but also diminish the redundancy information ; 2. in order to meet the requirements of making the dynamic simulation of trunking group system, the ms ’ s random move equation is brought forward, the simulation of ms ’ s distribution is done and the integrated channel model are presented ; 3. the smart predicative model of power control is introduced to overcome the delay and track the change of the complicated network, with this model, the power control ‘ s performance is greatly improved

    全匯報方法存在冗餘的匯報信息，而且實時性較差，為了改善實時性提出了多通道的匯報方式，為了改善冗餘匯報而提出了篩選法，最後介紹的碰撞法在減少冗餘信息的同時又提高了實時性;二、為了集群功率控制動態模擬的需要，提出了移動臺的隨機運動方程，進行了有關移動臺的分佈模擬，建立了綜合的通道模型;三、希望克服延時和跟蹤復雜網路環境變化，提出了功率控制的智能預測模型，通過智能預測模型可以改善功率控制的性能，著重介紹了採用神經網路的方法實現智能預測的通用模型，從而跟蹤復雜多變的無線環境，諸如慢衰落及快衰落（包括多徑衰落、多普勒效應所引起的衰落）等網路特徵，達到預測功率需求;四、採用二級正交碼和智能天線（空分多址）的方法進行組內用戶的識別，改進功率控制效果;五、話權用戶的前向和反向功率控制方法;六、對引入gota的cdma系統提出了復合容量表示方法，並作容量分析，探討有關gota系統的qos問題。
  19. 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
  20. Optical code multiple access ( ocdma ) communication system is a spectral spreading system. all users in the system share all the bandwidth in the same time. because of the using of the almost infinitude bandwidth in the fiber, ocdma system will become more and more important in future ultra - high speed lan and online computer communication system

    光碼分多址（ ocdma ）通信系統，作為一種擴展頻譜系統，用戶同時共享所有帶寬，因為可以充分利用光纖中的巨大帶寬資源，因此在未來超高速局域網和實時計算機通信系統中將扮演重要角色。
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