multiple access channel 中文意思是什麼

multiple access channel 解釋
多路存取通道
  • multiple : adj 1 多重的；復合的 復式的 多數的 多樣的。2 倍數的 倍。3 【電學】並聯的；多路的 復接的。4 【植物...
  • access : n. 1. 接近；會面。2. 捷徑，門路〈指方法、手段〉；檢查孔；進路，入口；【自動化】（存貯器的）存取。3. （病的）發作；（怒氣等的）爆發。4. 增加。
  • channel : n 1 水路，水道，渠，溝；海峽；河床，河底。2 （柱等的）槽，凹縫；【機械工程】槽鐵，凹形鐵。3 〈比...
  1. Is - 95, a wireless digital cellular standard based on cdma ( code division multiple access ), adopts convolution code as its channel coding part. the third generation wireless cellular standard adopts turbo coding, which stems from convolution coding, as its channel coding part

    以cdma （ codedivisionmultiplexaccess ）為基礎的數字蜂窩標準is - 95採用卷積碼作為其糾錯方案;第三代數字蜂窩無線通信標準也採用并行級聯卷積碼（ turbo碼）作為其糾錯方案。
  2. 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。
  3. Fa _ maca is an improvement of the well known maca ( multiple access collision avoidance ) protocol, which not only avoids the " hidden terminal " problem in wireless channel, but also adaptively adjust the access delay based on the traffic flow and traffic priority of the network

    將多業務種類的不同接入時延調整策略和傳統的maca多址接入協議相結合，提出了應用在adhoc網路中的流量自適應的maca接入協議? fa - maca 。
  4. 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
  5. The directional routing protocol ds _ dsr put forward by the author is the improvement of the current protocol dsr, complete routine discovery and maintenance by directional neighbor nodes routing table, source routing and directional steering. the research discovers the application of the directional antenna, compare the omnidirectional antenna can increases the networks " total throughput, obviously reduces the co _ channel interference ( cci ), multiple access interference ( mai ), enlarges the nodes " signal and interference to noise ratio ( sinr ), and because of the high gain of directional antenna can realize the communication with farther distance and less jump, end to end delay can decrease deeply, simultaneously, security of networks can be improved partially, the node energy also can be saved easily by power control

    本文提出的定向路由協議ds _ dsr是基於對現有協議dsr的改進下實現的，通過定向鄰節點路由表、定向源路由和定向搜索來完成路由發現與維護。研究發現，定向天線的應用，相比全向天線可明顯提高網路的總的吞吐量，減少通道干擾、多址干擾，提高信干噪比，且由於定向天線的高增益可實現較遠距離、較少跳數的通信，減少了路由發現時間，這樣大大減小了傳輸時延，網路的整體性能得到了不同程度的提高，同時部分地解決安全問題，通過功率控制還可較容易的實現節能的目的。
  6. Simulation results show that abf - csma / ca protocol can realize space - division - multiple - access ( sdma ) and provide very high channel utilization. chapter 3 considers employing smart antennas in the central access point ( cap ) of wireless internet access networks

    第三章研究了智能天線在internet無線接入網路中的應用，主要考慮使用智能天線對抗同通道干擾與多徑衰落，增加覆蓋范圍，並在mac層實現智能天線與網路的有機結合。
  7. The paper contains all kinds of knowledge related to the system, including maxwell electromagnetic theory, pattern of optical radiation in space, channel model of atmosphere communication, computer communication protocols, wireless lan communication protocols, medium access control protocol, carrier sense multiple access / collision detection protocol, manchester coding theory, pulse position modulation coding theory and so on

    主要包括： maxwell電磁理論；發送光場模型；空間通道模型；計算機網路通信技術：無線局域網通信技術；媒體訪問控制規程（ mac ） ；載波檢測多址接入碰撞檢測規程（ csma cd ） ；曼徹斯特編碼與ppm編碼技術等。
  8. Simulations results under rayleigh fading channel and on / off traffic model show that asama protocol can effectively support the application of smart antennas and provides high channel utilization and low delay. in chapter 5, we propose a qos ( quality - of - service ) - supported adaptive slot allocation multiple access ( qasama ) protocol

    在考慮多波束智能天線，及話音與數據業務特點的基礎上，提出了提供qos保障的自適應時隙分配多址接入協議（ qasama 、 。
  9. Based on ica post processing matched filter multi - user detection lets the output of traditional matched filter to initialize the ica iterations, not only the known spread information of interesting user is used to overcome the uncertainness of ica, but also the character of statistical independence is used. the simulation results show that it advances the ability of traditional detector when the signal - noise - ratio is large. keywords code division multiple access ; independent component analysis ; channel estimation ; matched filter ; blind multi - user detection

    基於ica后處理的匹配濾波多用戶檢測是用傳統的檢測器的輸出來初始化ica的迭代，它不但充分利用多用戶信號的已知信息，克服了ica的不確定性問題，同時也充分利用了多用戶信號的統計獨立性，模擬實驗結果證明這種多用戶檢測演算法在高信噪的情況下，誤碼性能改善隨著信噪比的提高不斷增加。
  10. In recent years, with the increasingly demand of the broad band and multimedia communication, various powerful tools have been emerging in endlessly to increase the capacity of satellite channel and pcma ( paired carrier multiple access ) is just one of them

    近年來，隨著人們對寬帶和多媒體信息需求的日益增長，各種衛星通道容量倍增技術層出不窮，成對載波多址（ pcma ）技術即是其中的一種。
  11. Because of the affection of noise and signal fading, in order to high data rate access and high quality, wireless communication need new technology to improve the link reliability and enhance the spectrum efficiency. mimo ( multiple input and multiple output ) can enhance the spectrum efficiency and increase channel capacity greatly, and reduce the multipath affection without spectrum band and power increasing. the 3th generation mobile communication wcdma is coming, with the purpose of putting mimo, stbc ( space time block coding ), space diversity into practice of wcdma systems, in order to lay the foundation of 3g toward 4g, this dissertation has done some research under this background

    在發射機和接收機使用多個天線進行數據傳輸的多輸入多輸出（ mimo ）技術，可以在不增加帶寬和天線發送功率的條件下，成倍的提高頻譜利用率，提高系統的通道容量，還可以抗多徑干擾。第三代移動通信wcdma即將到來，為了將多天線技術（ mimo ） ，空間分集技術，空時編碼技術用到wcdma系統中去，為第三代移動通信向第四代移動通信系統平穩過渡奠定一定的基礎，需要做一些理論上的研究。
  12. If the assigned spreading codes are orthogonal and signals are transmitted through a flat fading channel, there will be no multiple access interference ( mai )

    如果所有用戶採用理想正交擴頻碼並且通過同步平坦衰落通道，系統中將不會存在多址干擾（ mai : multipleaccessinterference ） 。
  13. Two major factors that limit the performance of ds - cdma systems are multipath channel distortion and multiple - access interference ( mai )

    對于ds - cdma移動通信系統，通道的失真與多址干擾是限制系統性能的主要因素。
  14. A polling - based adaptive beamforming multiple access ( pb - abfma ) protocol is proposed. in pb - abfma, the simple and effective mechanism is used to guarantee the smart antennas to adapt the time - varying channel. the cap schedules packet transmissions based on the polling mechanism and dynamic tdma

    該協議中採用簡單、有效的機制保證智能天線快速、準確地適應時變通道，以動態tdma方式為各節點安排發送時隙，採用微時隙為處于空閑狀態的用戶保持連接以降低接入時延，該協議可工作于異步網路中，具有很強的實用性。
  15. 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
  16. Cdma ( code division multiple access ) technology is used in communication system abroad because of its merit, people use cdma technology to transmit data, image and also other different information in different sub - frequent bands of a broad channel. so a research, which combines multi - carrier signal processing and cdma technology and processes different sub - frequent bands signal at same time, is full of practicable value

    Cdma技術由於其優點被廣泛採用在通信系統中，人們在一個寬帶通道的不同子頻段上使用cdma技術傳輸數據、圖像等不同信息，所以將多載波信號處理與cdma技術聯系起來進行研究，並且同時將不同的子頻帶信號進行處理是一個很有實用價值的問題。
  17. Based on the idea of contention reservation access and polling transmission, user - dependent perfect - scheduling multiple access ( upma ) protocol is presented, which supports both node mobility and multi - hop network architecture. it improves channel utilization greatly and guarantees that a node accesses the channel rapidly

    基於有效競爭預約接入、無沖突輪詢傳輸的思想提出了在無線adhoc網路中支持節點移動性和多跳網路結構的依據用戶妥善安排的多址接入（ upma ）協議。
  18. Aiming at the wireless optical channel and operation characteristics, carrier sense multiple access / collision avoidance ( csma / ca ) mac protocol is put forward taking into account the bit error rate ( ber ). this paper studies the protocol theory, access mechanism detailedly, and models the throughput performance, simulates and analyzes the performance. the paper analyzes the performance influence factors such as ber, transmit probability, number of the terminals, initial windows, retry limit and so on

    （ 2 ）針對無線光局域網的通道特性及業務特徵，在考慮通道誤碼率影響的基礎上，分析了基於載波監聽/沖突避免（ carriersensemultipleaccess / collisionavoidance ， csma / ca ）接入的無線光局域網mac協議，詳細闡述了協議原理和接入機制，用馬爾可夫模型對mac吞吐量性能進行了建模，並進行模擬計算和分析，詳細討論了在基本接入機制和rts / cts接入機制下，通道誤碼率、終端發送概率、終端數、初始化窗口、重傳極限等參數對吞吐量性能的影響，同時對兩種接入機制性能進行了比較分析。
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