衰落速率 的英文怎麼說

中文拼音 [shuāilàsùlǜ]
衰落速率 英文
rate of fading
  • 衰 : 衰動詞（衰弱） decline; wane
  • 落 : 落名詞[方言] （北方對蓮花落的俗稱） a kind of folk song
  • 速 : Ⅰ形容詞（迅速; 快） fast; rapid; quick; speedy Ⅱ名詞1 （速度） speed; velocity 2 （姓氏） a surna...
  • 率 : 率名詞（比值） rate; ratio; proportion
  • 衰落 : decline; be on the wane; go downhill; fading; decay; decaying; lapse; erode
  • 速率 : speed; rate; tempo
  1. Based on fractional sampling method, a new super - exponential iteration decision feedback blind equalization algorithm for severely nonlinear phase distortion channels was proposed

    因此針對嚴重頻率衰落和非線性相位失真通道，提出了一種分數采樣的混合盲均衡演算法，並獲得了較快的收斂速度和較小的剩餘均方誤差。
  2. Shortwave channel is time varying transmission channel. it has dispersion in frequency and time domains. this characteristics hinds the data transmi - ssion at high speed and the correction of received data. in this dissertation i have analyzed the statistic characteristic of shortwa - ve channel, established the model of shortwave channel and simulated the rayl eigh fading distribution. the technology of spreading spetrum has been proved that it has the capability for anti - multipath and discerning multipath

    在短波通信中，由於通道的時間色散和頻率色散，引起多徑展寬和多徑衰落，前者限制了數據的傳輸速率，後者造成短波數據通信中出現突發錯誤，為了解決多徑效應對短波通信的影響，本文所做工作如下：首先詳細分析了短波通道的統計特性，建立其數學模型；其次分析了擴頻通信的特點，從理論上證明擴頻技術不僅具有抗多徑干擾能力，而且具有分離多徑的能力；介紹了傳統的rake分集合併技術的特點。
  3. In this thesis, for the merits of high frequency spectrum utility factor and high - speed data communication, the ofdm is introduced into the underwater acoustic communication. combined with fec to combat the frequency - selective fades and isi in the underwater acoustic channel, high speed data transmission is realized by employing ofdm technology

    本研究嘗試將ofdm技術引入水聲通信領域，利用該技術頻譜利用率高，多載波并行傳送的特點，結合通道編碼，以克服水聲通道多徑干擾引起的頻率選擇性衰落和碼間干擾，獲得高速率數據傳輸。
  4. And the most advantage of ofdm is that it can convert high - rate data stream into the low - rate and reduce data bandwidth so that multi - path - fading can be transformed into flat fading in wireless circumstance

    這種調制技術的最大的好處就是將高速的數據流，變換成并行的低速數據流，減小了數據帶寬，從而可將無線環境中的多徑衰落（頻率選擇性率落）轉換成平坦衰落。
  5. It consists of a powr compensation algorithm based on reverse channel prediction and closed - loop power control algorithm. computer simulation showed that the scheme could compensate the fast channel fading quite well

    它由基於反向通道預測的功率補償演算法和常規閉環功率控制組合而成。計算機模擬結果表明，所提出的組合功率控制方案能夠很好地補償通道的快速衰落。
  6. The following algorithms have been proposed and tested in the thesis : 1 frequency selective fading : combine the isomorphism between the input space and the output space and propose a new approach to blind equalization of the channel. compared with conventional methods, the new approach offers lower computational complexity, better performance, and more robust against the over - determination of the system order ; 2 time selective fading : a new approach to the equalization of time selective channel based on the zero - forced equalizer is proposed which is more simple in its structure of algorithm ; 3 time - varying channel : using the instantaneous mean value changes of the output signal to extract the information of channel variations and model it using ar model, kalman filter is then employed to track channel variations, it bears faster ability in tracking the variation of tv channels ; based on the isomorphism between the inputs and the outputs and some of the approaches using in mimo system, a new algorithm of equalization of simo time - varying channel is proposed, which also share the merits of being robust against the over - determination of the system order ; model the time - varying channel using the multi - resolution decomposition wavelets, and then a blind identification method based " on the model is proposed ; at last, a new model for equalization and identification of mimo system is proposed

    主要工作在以下幾個方面： 1 、針對頻率選擇性衰落通道：結合輸入輸出空間同構關系提出一種新的頻率選擇性通道均衡方法，與傳統方法相比，該方法計算量更小，收斂速度更快，性能更優，且對系統階次的過確定表現穩健，具有實際均衡應用價值； 2 、針對時間選擇性衰落通道：提出一種基於迫零均衡的時間選擇性通道均衡方法，演算法結構簡單； 3 、針對時變色散通道：利用瞬態均值曲線提取通道時變信息，對之ar建模，利用卡爾曼濾波器跟蹤時變通道抽頭變化，可以快速跟蹤通道變化；基於輸入輸出空間之間的同構關系以及多輸入多輸出系統的處理方法，提出了新的單輸入多輸出色散時變通道均衡與識別演算法，同樣具有對通道階次過確定保持穩健的優點；結合小波多解析度分析提出一種基於小波模型的通道盲識別演算法；研究時變的多輸入多輸出系統的盲均衡與盲反卷積問題，給出一種時變系統處理模型。
  7. When transmitting signal is below 500 kbps, increasing the system power can reduce the bit error rate ( ber ) for the signal suffering only flat fading

    當碼速率較低時（ 500kbps以下） ，信號受到平坦衰落，增大系統功率可以降低系統誤碼率。
  8. But when the bit rate is above 1 mbps, the signal suffers frequency select fading, which causes the serious intersymbol interference ( isi ). increasing the system power can ’ t reduce the ber

    但是當碼速率提高到1mbps以上時，信號受到頻率選擇性衰落，碼間干擾嚴重，增大系統功率也不能降低系統誤碼率。
  9. A simulation and modeling mechanism is studied and proposed for multirate transmission protocol. based on the wlan that adopts ofdm transmission technique, we first assumed that the small - scall fading and multipath in ofdm sub - channel is rayleigh, and large - scale path loss could be described by bi - linearity model, and then we analyzed the rationality

    基於採用ofdm傳輸技術的wlan ，我們假設ofdm子通道的小尺度衰落服從rayleigh分佈，路徑損耗可以用雙線性模型描述，並對假設的合理性進行了分析，將決定速率切換的誤幀率等物理層性能參數和媒質控制協議有機地結合在一起，對多速率傳輸建模進行了有意的探索。
  10. In this scheme, power control is primary to the rate control. when the fading channel changes slowly, the transmit data rate will be kept on an appropriate level, and only the power control works to keep up with the channel fading and balance the sir. but when the channel quality is poor, the data rate will be switched down without sacrificing the ber ; otherwise, high data rate was selected

    我們提出的方案根據反饋的sir動態改變數據的速率和功率，其中功率控制優先於速率控制，當通道變化緩慢時，數據率保持在一個相對穩定的值上，調節發射功率來維持sir平衡；當功率調節無法彌補通道的衰落時，則通過調節速率來維持sir的平衡。
  11. This model has the ability of analyzing the effects of some key system parameters, such as the signal correlation coefficient, speed of the mobile, and the update rate of combining weights, on the system performance

    研究了信號相關系數、移動臺運動速度、通道衰落率，以及合併權值更新速度對合併性能的影響。
  12. The underwater acoustic channel is very complex where cochannel interference, doppler frequency offsets, narrow bandwidth and time and frequency selective deep fades obstructs the development of high speed and fidelity underwater data transmissions. thus projects of high speed and fidelity underwater signal transmissions become a hotspot in the fields of world academic circles. the conventional serial communication must use adaptive equalizer to combat the multipath in real - time

    海洋水聲通道是一種極其復雜多變的時-空-頻變參通道，其通道窄，強多途干擾，信號起伏衰落嚴重，一直是水下信息可靠高速傳輸的主要障礙，因此如何在水聲通道中高速率準確地傳輸數據，就成為世界性的熱門課題。
  13. It belongs to multi - carriers modulating technology, and its most remarkable character is the high - speed transmitting ability as well as the excellent resistibility to interface of signal interval and decline of channel selectivity

    它屬于多載波調制技術，其最大的特點是傳輸速率高，對碼間干擾和通道選擇性衰落具有很強的抵抗能力。
  14. Space time coding was proposed by combining transmit diversity and coding technology to improve the system performance, such as error bit rate, data rate, and system capacity. in particular, space - time block coding ( stbc ) schemes, proposed originally by alamouti were adopted by the 3g standardization committees as one key technique in 3g wireless systems

    將發送分集與編碼調制技術相結合，進一步產生了空時編碼技術，由於空時編碼技術具有優異的抗衰落性能，並且能通過發送分集和接收分集提供高速率、高質量的數據傳輸，因此它已經成為第三代移動通信技術的重要組成部分，並將繼續在下一代移動通信技術的發展中發揮重要作用。
  15. It has been proven that the spread spectrum technologies have good capabilities of overcoming isi in electromagnetic wireless channel. the feasibilities of their applications to underwater acoustic channel have been analyzed, the frequency hopping technology is chosen. instead of using time - frequency diversity, convolutional coding and viterbi decoding are employed to combat signal fading, consequently the bit - rate and bit - error - rate performance of the underwater acoustic voice communication system can be balanced and controlled

    由於擴頻技術在抗碼間干擾方面具有優良的特性，因此在分析了各種擴頻技術于本研究應用的可行性之後，確定了跳頻技術作為具體實現方案；在克服幅度衰落方面，選用卷積編碼和維特比譯碼方法來替代原有的分集技術以綜合調節系統的通信速率與誤碼性能，達到差錯可控的目的。
  16. Stfs is a good coding arithmetic which is simple and easy to realize. moreimportantly stfs has higher diversity order and encoding gain than sts at the samesymbol rate. it can repel channel fading, improve data rate and wireless systemcapacity availability, stand against frequency selectivity fading, eliminate theintersymbol interference

    該編碼演算法不僅在方法和原理上簡單，而且易於實現，在相同符號率下比空時擴頻具有更大的分集度和更高的編碼增益，能有效抵抗通道衰落、提高數據速率、提高無線系統容量、很好的對抗頻率選擇性衰落和消除符間干擾。
  17. Based on these advantages we analyze the performance of constant - power variable - rate m - qam schemes for spectrally efficient data transmission over nmf channels. by introducing the adaptive modulation approach, we gain two things : 1 ) the error rate is kept at a constant level. 2 ) the achievable spectral efficiency comes within 5 db of the shannon capacity limit. at the last chapter, the presentation of a single base station and a single mobile scenario proved the feasibility of adaptive schemes

    然後作者的精力轉入通道的自適應方案的研究中，首先通過研究發現nakagami衰落因子的適當調整可以近似於常見的瑞利衰落和萊斯衰落，接著研究在無線通道中採用三種不同自適應方案時的通道容量，研究表明速率的調整是增加通道容量的關鍵，在此基礎上，著重研究了離散變速率qam的情況，表明這種調制方案無論在頻帶利用率還是在系統平均誤碼率比其它情況提高很多。
  18. As a combination of ofdm with space - time coding technique, mimo - ofdm has recently received considerable attentions, which can not only effectively enhance the transmission rate and capacity of the wireless communication system but also effectively combat multi - path fading and interfere

    Mimo - ofdm技術將ofdm與空時編碼技術有機的結合在一起，能夠大幅度的提高無線通信系統的通道容量和傳輸速率，並能有效的抵抗多徑衰落、抑制干擾和噪聲，從而引起了通信界的廣泛關注。
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