time selective fading 中文意思是什麼

time selective fading 解釋
時間選擇性衰落
  • time : n 1 時，時間，時日，歲月。2 時候，時刻；期間；時節，季節；〈常pl 〉時期，年代，時代； 〈the time ...
  • selective : adj. 1. 選擇的；挑選的；有選擇性的；淘汰的。2. 【無線電】選擇性的。adv. -ly
  • fading : 淡變
  1. 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。
  2. A new approach to equalization of linear single - input single - output time - selective fading channel

    時間選擇性衰落通道迫零均衡新方法
  3. 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。
  4. Combined with the data - selected schemes proposed, the computational complexity of this method can be lowered. the performance of the presented rls method is analyzed by simulations, and it is shown that this method is interesting for application. 4 time - selective channel signal model based on multipath - doppler diversity representation is given in multi - path fast fading channel, and rls space - time receiver algorithm based on time - varied constraint condition is presented and the computational complexity of this method is analyzed

    4 、針對多徑快衰落通道下的ds - cdma系統，給出了基於多徑-多譜勒觀點描述的1百安電弓卜科東兔j憶學協士學位論文時間選擇性通道的信號模型，提出了基於變約束條件下的遞歸最小二乘空時接收機演算法並分析演算法的運算量，最後通過模擬分析了所提出的方法的性能。
  5. A time - varying disperse channel is a channel that contain both frequency selective fading and time selective fading

    時變色散通道則是同時存在頻率和時間選擇性衰落的通道。
  6. Space - time coded eigenbeamforming for downlink frequency - selective correlated fading

    下行頻率選擇性相關衰落通道下的空時特徵波束編碼
  7. Because of the different time delay among multi - paths, the received signal undergoes frequency - selective fading

    由於多徑干擾之間具有不同的時間延遲，接收信號將承受頻率選擇性衰落。
  8. Rtce is based on forecasting the inherent vulnerabilities to propagation of hf time - varying channel, including multipath delay, doppler spread, selective fading, interference, so this paper also introduces characteristics of hf channel in the beginning. familiar rtce systems all adopt envelope method that bello brought forward

    實時選頻技術是基於對短波電離層時變通道固有的不利於電波傳播的各種因素，包括通道的多徑展寬、多普勒展寬、選擇性衰落、噪聲干擾等的預測的基礎上實現的，所以在開篇對短波通道的特點進行了詳細的介紹。
  9. 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。
  10. However, multipath components can be resolvable due to the autocorrelation of the spread spectrum signal, thus the optimal receiver equals coherent rake reception, i. e. maximum ratio combining the independent components which endure flat fading or frequency non - selective fading. synchronization of pn code and separation of resolvable multipath components need to estimate the exact time delay among the multipath components

    但是利用擴頻信號的自相關特性，可分辨多徑可以被有效分離，最優接收機等效為對多個具有獨立平坦衰落通道（或頻率非選擇性通道）特性的多徑信號進行最大比合併，即相干rake接收。
  11. Because using ofdm, a frequency - selective fading channel can be transformed into multiple frequency - flat fading sub - channels, in the coding process, spatial diversity ( due to multiple antennas ) is integrated with frequency diversity ( due to delay spread ), therefore, the proposed code can provide higher diversity gain than space - time code alone

    該編碼利用正交頻分復用把頻率選擇性衰落通道變換成平衰落通道的特性，同時引入了基於多天線的空間分集和基於時延擴展的頻率分集，比空時編碼具有更高的分集增益。
  12. The relative motion between the base station and the mobile results in random frequency modulation due to different doppler shifts on each of the multi - path components, also called time selective fading

    由於基站與移動臺之間的相對運動，每條路徑都會有一個明顯的多普勒頻移，導致通道的隨機頻率調制，也稱時間選擇性衰落。
  13. Space - time block codes ( stbc ) based on orthogonal design has attracts enough attentions in its applications in mimo - ofdm systems for its full diversity exploiting and low coding / decoding complexity. these applications include not only system performance improvement, but also reduction of the peak to average power ratio in mimo - ofdm systems. under these backgrounds, this paper first studies space - time block codes under the single carrier, flat fading situation, discusses the encoding / decoding principle and its performance under different channels. then, the author focused on the performance of space - time codes under time selective and frequency selective channels, uncovered the fundamental cause of how maximum doppler shift and power delay profile influences the performance of space - time codes through deduction and simulation

    在上述背景下，本文以單載波，平坦衰落通道下的空時分組碼為切入點，深入分析了其編譯碼原理和在不同通道情況下的性能;以此為基礎，後文展開了對空時分組碼在多載波，時間選擇性和頻率選擇性衰落通道下的性能研究，通過理論推導和充分的模擬，揭示了空時/頻分組碼在時頻選擇性衰落通道中的性能變化的根本原因;在以上對多載波系統中空時分組碼的研究的過程中，作者發現了空時分組碼在降低系統峰平比方面應用的可行性，提出了一種降低峰平比的新方法。
  14. Time selective fading

    時間選擇性衰落
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