衰落比 的英文怎麼說

中文拼音 [shuāilàbǐ]
衰落比 英文
fading ratio
  • 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
  • 比 : Ⅰ動詞1 （比較; 較量高下、 長短、距離、好壞等） compare; compete; contrast; match; emulate 2 （比...
  • 衰落 : decline; be on the wane; go downhill; fading; decay; decaying; lapse; erode
  1. With one hand, mr qaddafi is opening libya to the world, inviting foreign investment and seeking advice on how to reform its moribund, oil - dependent economy

    一方面，卡扎非向世界敞開利比亞的大門，邀請外國投資並尋找良方來改革衰落，依賴原油的經濟。
  2. Because of the simplicity of differential detection system, we could consider to apply it to the selective fading channels instead of coherent detection

    由於差分檢測的簡單易實現性，當通道衰落比較嚴重時，可以考慮採用該方法替代相干檢測。
  3. This paper can be mainly summarized in to three aspects as follows : 1. firstly, the paper analyzes the system model of mimo, derive the formulas of channel capacity for the slow flat rayleigh fading channel, analyzes two improtant facts affected the system capacity, and then via the computer simulation we compare the channel capacity between the tranditonal wireless system and mimo system

    本文主要做了以下幾個方面的工作: 1 .分析了mimo系統的通道模型，理論推導了慢衰落平坦瑞利通道下mimo系統的通道容量公式，簡要分析了影響系統容量的兩個重要因素並且通過計算機模擬比較了傳統無線系統與mimo系統之間的通道容量。
  4. From the end of the qing dynasty to the year 1949, northwest petroleum industry, though experience the weather of development and declination, is still backward and need to be further developed, even in 1930s and 1940s it was still the case. it behaved as such : the scale is small, equipment is simple, yielding power is weak, and productive force is small, technique is poor, mechanization is low and modernization is not high

    從清未到1949年全國解放，西北石油工業經歷了40餘年的風雨，幾經發展、衰落的起起伏伏，卻仍處在比較薄弱的落後狀態，即便是發展最為迅速的20世紀30 、 40年代亦是如此，其主要表現為：生產規模小，設備簡陋；產量低，生產能力弱；技術落後，機械化程度低下；發展緩慢，近代化水平不高。
  5. Abstract : by comparing the channel capacities hetwem orthogonal space - time block coding and multi - antenna array system over rayleigh fading channel, some capacity loss for orthogonal space - time block coding is obtained, which is a function of the code rate, the rank of channel matrix and the number of transmitter and receive antennas, although the system of orthogonal space - time block codes is simple and easy to implemented. if is also shown that there is no capacity loss only if both the code rate and the channel matrix rank are all one

    文摘:在研究瑞利衰落條件下正交空時分組編碼通道容量的基礎上，將其與多發送多接收天線系統的通道容量進行了比較.比較結果表明，正交空時分組碼雖編碼簡單，易於實現，但在通道容量方面存在較大的損失，損失的程度與編碼碼率、通道矩陣的秩及收發天線數等因素有關.進一步研究表明只有當編碼碼率和通道矩陣的秩都為1時，才沒有通道容量的損失
  6. As the step of the color tv ( the second generation ) to the digital tv ( the third generation ) is larger and larger, the research of digital television terrestrial broadcasting ( dttb ) become more and more important in china, we are concentrating on the standard of dttb which is suit for our country after describing and analyzing the technical stipulation and speciality of dttb, this paper compares atsc 8 - vsb with dvb - t cofdm and isdb - t bst - ofdmo the emphasis of this article lies in the technical solution about transferring system, channel coding is important component of dttb, which can resist from the bad circumstances o because of lots of varieties and different performance, channel coding become one of the emphasis of the research work this paper analyzes and researches the theory and performance of the different channel coding particularly, points out an effective theoretic analysis method and computer demo of performance comparison a theoretical method for estimating the performance of concatenated codes is proposed in this paperc this is achieved by combining the performance of single level coding rayleigh fading channel and the character of channel modulation it may be useful to research and development of the future digital television terrestrial broadcasting standard of our country

    通道糾錯編碼是數字電視地面廣播傳輸系統的重要組成部分，是抵禦地面惡劣環境的有效手段。由於通道編碼的種類繁多，性能各異，因此是目前研究工作的重點之一。本文詳細分析和研究了幾種通道糾錯編碼的原理和性能，並針對外碼內碼級聯糾錯結合地面通道瑞利衰落提出了一種有效的理論分析方法和性能的計算機比較演示方案，總結了不同級聯方案的性能特點，對於我國目前的數字電視地面廣播標準的研究和通道級聯糾錯方案的確立及其參數選擇具有一定的參考價值。
  7. Under rayleigh fading channel, we also simulated and compared ber in siso 、 simo and mimo systems. secondly, based on careful study the ber and the channel capacity under white noise channel under mpsk modulation when the channel is rayleigh fading, we duduced the expressions of stbc ’ s ber and channel capacity under rice and nakagami fading. and also analysed the performances through numerical simulation using matlab to testify the exactitude of the dudeced expressions. finally, there exists an error floor of stbc through studying on its performance on time - selectiv fading channel. we analysed the reason and proposed two new decode combination scheme to eliminated the error floor and the performance of stbc on time - selective fading channel is improved. and also compared the two scheme ’ s complication and snr gain

    這些結果大部分是閉式結果，能比較準確地衡量空時塊碼的性能，並對不同衰落的性能做了相互比較，其結果對空時塊碼的實際應用具有一定的指導意義。實際的通道是時變的，分析了空時塊碼在時間選擇性衰落通道中產生誤差地板效應的主要原因是存在碼間干擾（ isi ） ，在此基礎上提出了兩種能消除誤差地板效應的譯碼合併方案，並對這兩種方案的復雜度和信噪比增益進行了比較。
  8. The conclusion is identified by computer simulation. the paper studies a noncoherent demodulation based on differential encoding in mc - cdma system and makes computer simulation of ber performance compared with that of coherent demodulation based on perfect channel estimation

    研究分析了一種使用差分編碼的非相干接收mc - cdma系統，對頻率選擇性瑞利衰落通道條件下的誤碼率性能進行了計算機模擬，並且和基於理想通道估計的相干解調方案進行了比較。
  9. The new method is a modified pts method, and can make good compromise between performance and computational complexity. the dissertation explores, by means of computer simulation, how the conventional method based on amplitude - limiting and filtering affects the performances of wavelet packet modulation signals, and presents a new method, namely, selective mapping / amplitude limiting / filtering method, which proves to be effective, simple, and have better ber performance

    並基於自子波變換和時間、尺度解析度的概念，從理論和模擬實驗兩方面對通道建模和時間/尺度rake接收機進行了分析，並與傳統的kake接收機進行了比較，結果表明時間/尺度聯合分集能有效地克服高速衰落多徑通道的影響。
  10. It was at rome, on the 15th of october, 1764, as i sat musing admidst the ruins of the capitol, while the barefooted friars were singing vespers in the temple of jupiter, that the idea of writing of the decline and fall of the city first started to my mind

    1764年10月15日，在羅馬，我坐在加比陀山的廢墟上發呆，聽見朱庇特深面里赤腳的修士們唱起了晚禱曲，這是有個念頭第一次湧上我心頭：寫下這個城市的衰落和滅亡的歷史。
  11. 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。
  12. 3 a novel recursive least - square ( rls ) blind space - time receiver algorithm based on the constrained condition, which can completely avoid the matrix inversion introduced into by constraints ( comparing with the normal rls ), is proposed for multi - path slow fading cdma channels. the computational complexity of this method is not only lower than that of the normal rls, but also lower than that of both lms and ls blind space - time receiver methods that are realized based on the rosen ' s gradient projection. and the speed of convergence of the presented rls blind space - time receiver algorithm is better than that of both lms and ls blind space - time receiver methods

    3 、針對多徑慢衰落通道下ds - cdma盲空時接收機中線性約束二次規劃問題提出一種新的遞歸最小二乘演算法，該演算法完全避免因約束而引進的矩陣求逆運算（相對于常規的遞歸最小二乘演算法） ，不但運算量比常規的要低，而且比基於rosen梯度投影實現的最小均方（ lms ）與最小二乘盲空時接收機演算法還低，且收斂速度比基於rosen梯度投影實現的最小均方（ lms ）與最小二乘盲空時多用戶檢測都好，將提出的新的遞歸最小二乘演算法與提出的數據選擇方案結合起來可以進一步降低其運算量，具有很大的實用價值，最後通過模擬實驗進一步分析了其性能。
  13. This thesis first studied the communication system with detailed theories so that to choose the appropriate method of modulation and demodulation. n / 4dqpsk is a kind of modulation method which is appropriate to transfer in the attenuated channel

    / 4dqpsk是一種比較適合在衰落通道中傳輸的調制方式，它不需要提取相干載波，因而不存在相位模糊、環路跳周等問題。
  14. 5. the detailed compare of the different topologies of receiver based on the in - depth analysis of each part of rfic. and their analysis and simulation results based on different wireless communication standards are also given

    在對射頻集成電路各部分詳細分析以及無線通道衰落特性估計的基礎上，對射頻接收晶元（ receiver ）的不同拓撲結構進行了對比和分析。
  15. In this paper, we discuss the principle of mimo - ofdm system based on the introduction of fading channels. furthermore, the channel estimation technique in mimo - ofdm system is investigated, with the emphasis on training sequence - based and pilot - based channel estimation methods, and also several basic and improved algorithms are given respectively. finally, the analysis and comparison of these algorithms is made by computer simulation

    本文在分析移動無線通道衰落特性的基礎上，闡述了mimo - ofdm系統的基本原理，並圍繞該系統中通道估計這一關鍵技術，深入研究了基於訓練序列和基於導頻符號的兩類通道估計方法，給出幾種相應的通道估計演算法以及它們的改進演算法，最後結合matlab模擬對這些演算法的有效性和可行性進行了全面地分析與比較。
  16. ( 3 ) for the wireless channels subject to several types of fading existing in different time scales, the dynamics of channel conditions are decoupled into two random processes with different mathematic properties in different time scales. two algorithms in this scheme are proposed to dealing with each time scale : the resource optimizer allocates the resource to maximize the total revenue with price fairness and provide qos guarantees to applications, and the slot scheduler exploits the time variability of

    （ 3 ）針對無線通道衰落的多時間尺度特性，將通道條件snr分解到不同時間尺度上，在不同時間尺度上針對不同的衰落特性來設計不同的演算法，完成不同的任務：在大時間尺度（幀）上進行資源分配，面向應用提供qos保證，保持應用間price公平性的情況下，尋求系統總收益utility的最大化；在小時間尺度（時隙）上進行時隙調度，利用各用戶通道容量的時變性，使各用戶獲得比平均通道條件情況下更高的吞吐量。
  17. The simulation results show that our algorithm is effective in tracking the changing of channel without deep fading under the condition that transmission efficiency has been double compared with [ 113 ] with the same sub - carriers ; it is also effective to track the channel with deep fading under the condition that transmission efficiency has been increased obviously when linear precoded technology is used

    模擬結果表明，當fir通道沒有深度衰落時，本文的演算法在相同的子載波和比[ 113 ]傳輸效率提高一倍的情況下，能有效地自動跟蹤通道的變化；當通道有深度衰落時採用線性預編碼的情況下，本文的演算法在比[ 113 ]傳輸效率有較大提高的情況下，也能有效地跟蹤通道的變化。
  18. It is based on the mean square error ( mse ) principle and we prove the validity of the method by computer simulations. to make a thorough understanding of mimo adaptive equalization system, in this thesis the author : 1 ) ananlyze the characteristics of mimo wideband channels and the modeling and simulation of 3gpp scm ; 2 ) research the capability of mimo linear adaptive equalization and mimo non - linear adaptive equalization by computer simulations ; 3 ) present a new method for selecting the order of adfe model 4 ) implement the adfe on adsp - 21160 for static image transmission, and already achieve satisfactory experimental result, which make a foundation for mimo adaptive equalization to be appllied in the real communication systems

    為對mimo自適應均衡系統性能和設計做更深入的理解和研究，本文主要: 1 ）研究了寬帶選擇衰落通道特性及3gppscm通道建模模擬; 2 ） mimo線性自適應均衡器和mimo非線性自適應均衡器系統的性能分析和模擬實現; 3 ） mimo系統下的判決反饋均衡器的階數選擇模擬試驗分析; 4 ）把mimo自適應判決反饋均衡運用到了硬體模擬平臺上，採用了基於adsp - 21160的硬體dsp開發板，對靜止圖片的傳輸進行了試驗、分析和比較，得到了較滿意的實驗結果，使mimo自適應均衡在實際通信系統上的應用及實現奠定了現實基礎。
  19. Second, this paper design the simulation scheme of bicm for comparing the performance over fading channel and awgn channel that combine 2 / 3 rate, 4 states punctured convolutional code with 8psk modulation, matching block interleave or random interleave, transform through rayleigh channel or awgn channel and use the way that combine coherent demodulation with viterbi decoding in receiver. design the scheme of bicm _ id that use the iterative decoding technique and the scheme of tcm for compare

    為了驗證bicm和bicm _ id在衰落通道和加性高斯白噪聲通道（ awgn ）下的性能，設計了一個2 / 3碼率， 4狀態的鑿孔卷積碼經過塊交織或隨機交織，與8psk調制相結合，在rayleigh通道下或awgn通道下傳輸，接收端採用相干解調與維特比譯碼相結合的bicm方案，在接收端引入迭代反饋譯碼的bicm _ id方案，以及與之相比較的tcm方案。
  20. Comparison study between the constant modulus decision feedback equalizer ( dfe ) and several others is made on combating the frequency selective fading of uwac, and their tracking performance to time varying is also investigated

    ?針對水聲通道的頻率選擇性衰落，對比研究了常數模判決反饋盲均衡演算法與其它幾種盲均衡演算法的性能。針對水聲通道的時變特性，研究了該演算法的跟蹤摘要性能。
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