downlink 中文意思是什麼

downlink 解釋
下傳
  1. Application of antenna arrays to downlink of ofdm systems

    系統下行鏈路中的應用
  2. New satellite tv uplink and downlink licence granted

    政府發出新星電視上行及下行牌照
  3. The conventional sphere model of earth and circle model of orbit are discarded, and the ellipsoid model and the ellipse model are selected for further research, which achieves a method to determine the target position through the antenna pointing direction. and the spaceborne sar system design and simulation software is brought forth. this software accomplishes sar system coefficients design for antenna area, pulse repetition frequency, signal bandwidth, downlink data rate, radar transmitter power and satellite platform yaw steering

    本文從星載雷達的星地幾何關系入手，舍棄傳統星載合成孔徑雷達研究中的球地球模型和圓軌道模型，研究了在地球橢球模型和橢圓軌道模型下由雷達天線確定目標坐標的方法，並在此基礎上研製了星載合成孔徑雷達系統設計與模擬軟體，完成雷達系統天線尺寸、脈沖重復頻率、信號帶寬、雷達信號數據率、雷達發射功率、衛星平臺的偏航牽引等幾個方面的系統參數設計以及雷達多普勒特性、雷達系統模糊、雷達定位及精度的分析，最後完成雷達回波信號的模擬。
  4. B3g designs a flexible frame which can adapt to different data transfer rates between downlink and uplink and can adapt to variable mobile speed

    B3g設計了適用於上下行不同數據量要求的幀結構，以及適用於不同移動臺速度的時隙結構。
  5. Hsdpa is written in release5 to increase transmit speed in certain time. as researchers found that the amount of data between downlink and uplink is unequal, and the former one has a larger amount than the latter one

    針對3g系統中不對稱的上下行傳輸，下行鏈路業務量普遍大於上行鏈路業務量這一典型特徵， 3gpp在release5協議版本中提出了hsdpa概念，旨在提高某一時刻的傳輸速率。
  6. 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。
  7. Hsupa ( high speed uplink packet access ) is the new technique of r6, first in this thesis, the hsupa physical layer is introduced in detail. then base on the physical layer technique characteristic, according to the 3gpp simulation requirements and system simulation requirements, the hsupa downlink and uplink can be constructed by using matlab. then the data channel and control channel can be simulated, so the channels performance can be realized, provide the results can be provided to the system simulation, these ground the future practical applications

    Hsupa （ highspeeduplinkpacketaccess ） ? ?高速上行分組接入就是r6版本中的新技術，本文首先詳細介紹了hsupa物理層的技術特徵，然後以其技術特點為依據，按照3gpp的模擬需求和系統級的模擬需求，使用matlab構建hsupa的上下行物理層鏈路，對其數據通道和控制通道進行模擬驗證，從而了解通道的性能，為系統模擬提供模擬數據，為以後的實際應用打下基礎，達到預研的目的。
  8. We also present a low - complexity general channel simulation model for both transmitter diversity case and downlink beam - forming case. finally, we implemented the mimo channel model by dsp, introduced the software and hardware platforms of the channel simulator

    最後，用dsp對所建立的多入多出通道模型進行了模擬實現，並介紹了整個硬體電路板的整體結構，給出了通道模擬器的軟體實現過程。
  9. Smart antenna has two critical tasks, one is to filter the uplink signals, and the other is to form the downlink beam, and we need adaptive algorithm and digital signal processing ( dsp ) technology to fulfill these work. adaptive algorithm is one of the most important technologies of smart antenna, and it determines smart antenna ' s speed to the wanted to signal and the complexity of the circuit of the communication system

    自適應演算法是智能天線的核心技術之一，它決定著智能天線對來波信號響應的速率和系統實現電路的復雜程度，系統需要針對各種通信環境來選擇合適的演算法，也可以採用演算法分集的方法來使整個系統工作在最佳狀態。
  10. Game, players control a breeze next to the fireballs, in a narrow channel downlink, the whereabouts of the process, hit both sides of the need to avoid the walls, and as much as possible the elimination of the flies flew method is a fireball flies physical contact

    游戲中，玩家控制一個上下飛舞的火球，在一個狹長的通道中下行，在下落的過程中，需要避免撞到兩側的墻壁，同時，盡可能多的消滅飛來飛去的蒼蠅方法是使火球接觸蒼蠅身體。
  11. Uestc is in charge of the tdd downlink that bases on fpga. low density parity - check ( ldpc ) codes were first discovered by gallager in the early 1960s and recently have been rediscovered and generalized

    低密度奇偶校驗碼（ ldpc ）碼是由gallager在1962年首先提出的一種糾錯碼，在沉寂了多年之後，最近又重新成為通信技術研究的熱點。
  12. 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。
  13. Compared with the fdd system, td - scdma adopting tdd, has no need of symmetrical frequency bands for uplink and downlink, and enables flexible and convenient planning and use of increasingly scarce spectrum resources

    與fdd系統相比， td - scdma採用時分雙工方式，上下行無需對稱頻段，可以見縫插針，靈活方便地規劃使用日益緊張的頻譜資源。
  14. Traditional delay estimation based on ica requires the trail sequences to initialize the receiver, but the new algorithm based on ica does not need the trail sequences. it is based on the channel character of downlink, using the ica algorithm to estimate the multi - path mixture matrix, then, find the delay information which is embodied by the column vector of the mixture matrix. the simulation results show that it does enhance the performance of traditional detector without wasting the invaluable frequency resource

    傳統的通道估計演算法需要訓練序列使接收端的參數調整到理想狀態，而本文提出的基於ica的通道估計的多用戶檢測演算法不需要訓練序列，它是利用下行通道的固有特點，用ica的盲源分離法估計出多徑通道的卷積矩陣，從而從中提取出通道的延遲信息，模擬實驗結果證明這種方法在節省了頻譜資源的同時取得較好的估計效果，使得傳統的接收機的誤碼性能得到了很大的提高。
  15. After introduction of the whole fpga design of b3g downlink, chapter four schemed out every function module such as time synchronization, frequency synchronization, timing recovery, last frame detect, ofdm demodulation and rocket i / o interface etc. lots of structure schemes and simulation waves were presented

    主要包括時間同步模塊、頻率粗同步模塊、頻率精同步模塊、定時恢復模塊、尾幀檢測模塊、 agc / afc輔助模塊、 ofdm解調模塊和rocketi / o介面模塊等。
  16. Wireless wide - area networks ( wwans ) are charactered by very low and variable bandwidths, very high and variable delays, significant non - congestion related loss, asymmetric uplink and downlink channels, and occasional blackouts. additionally, the majority of the latency in a wwan connection is incurred over the wireless link

    無線廣域網（ wwans ）由於以下特徵而有別于有線廣域網（如internet ） ：較低並且易變的帶寬，很高且易變的延遲，與擁塞無關的數據丟失，非對稱的上行和下行通道，以及偶爾的昏眠狀態，此外，在無線廣域網上的大部分的延遲發生在無線連接部分。
  17. Coupling can happen at different places of the uplink and downlink channels

    上下行通道之間產生耦合的原因有多種，避雷設施的安裝不當也是其中之一。
  18. 4. we propose that the best detection method for the uplink mc - cdma system is decorrelating - parallel interference cancellation ( dec - pic ) multiuser detection, and the best detection method for the downlink mc - cdma system is minimum mean square error combining ( mmsec ) single user detection

    提出上行通道mc - cdma的最佳檢測方法是解相關-并行干擾抵消多用戶檢測法（ dec - pic ） ，在下行通道mc - cdma的最佳檢測方法是最小均方誤差合併單用戶檢測法（ mmsec ） 。
  19. 3. we propose a new spreading sequence design scheme. in the uplink, using golay sequence, cinew sequence or zadoff - chu sequence, in the downlink, using wh sequence as the spreading sequence, we can control the papr of mc - cdma below 7db and ber below le - 3 ( snr = 20db )

    提出mc - cdma中擴頻序列的新型設計方案，在上行通道，採用golay序列， cinew序列或zadoff - chu序列，在下行通道，採用wh序列作為擴頻序列可以控制mc - cdma峰平比在7db以內，在信噪比為20db時，系統誤碼率小於1e - 3 。
  20. It is particulary suited to multirate signal transmission due to the use of an offset stacked spreading modulation scheme, which simplifies th ' e rate - matching algorithm relevant to multimedia services and facilitates asymmetric traffic in up - and downlink transmissions for ip - based applications

    通過調整偏移棧，偏移的大小，可簡化多媒體服務的速率匹配演算法，特別適用於ip網路中上行鏈路和下行鏈路非對稱業務的傳送。
分享友人
分享到 Line

分享到臉書