flat fading 中文意思是什麼

flat fading 解釋
按比例衰減
  • flat : n 1 〈英罕〉地板;(房屋的)一層。2 一套房間;〈pl 〉分宅公寓〈美國高級公寓叫 apartment house〉。...
  • fading : 淡變
  1. And then facing the problem of the channel estimation of the adaptive modulation system, we conclude out the channel estimation algorithms on maximum likelihood ( ml ) estimation and maximum a posteriori ( map ) estimation under the condition of flat fading channel and selective fading channel in detail. to meet flat fading channel, we simulate the relationship of the ratio between the error covariance in map estimation and ml estimation and pilot symbol message length. the conclusion can be drawn from these results

    接著,對自適應調制系統中的通道估計問題難點,詳細推導了平衰落通道條件下和選擇性衰落通道條件下最大似然( ml )估計和最大后驗概率( map )估計演算法,針對平衰落通道,我們模擬了map估計和ml估計的方差與導頻符號長度的關系,模擬結果表明,錯誤方差受多譜勒頻率的變化影響最大,並且對實際的自適應調制系統,導頻符號長度的取值超過20個符號長度時, map通道估計明顯優于ml通道估計。
  2. Then this paper makes some overview and simulation on the application of three precoding algorithms under the flat fading channel, which are linear preequalization, tomlinson - harashima precoding ( thp ) and lattice reduction - aided ( lll ) vector precoding

    本文對三種常見的預編碼演算法在平坦衰落通道下的應用進行了綜述和模擬研究,包括迫零線性預均衡、 thp預編碼和格約簡輔助矢量預編碼等演算法。
  3. 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。
  4. The basic idea of this method is to produce particles from the posterior densities, and these weighted samples provide approximations to the densities. in this dissertation, sequential monte carlo method and its applications in communication are investigated. firstly, its basic idea, method and improved method are introduced, then induce the bound of particles, which determines the performance of the system, and the more particles are chosen, the higher computation is done, finally, a new detector based on new importance function is proposed, which deals with the joint channel estimation and detection in flat fading channels

    首先介紹了它的基本思想、基本方法、及當前研究現狀;在此基礎上推導出樣本數選擇的界,樣本數的選擇決定了系統的性能,但是若選的太多,計算復雜度也會隨之增大,因而給出這個界是十分有意義的;最後提出了一種基於新的重要函數的檢測器用來解決平坦衰落通道下的聯合通道估計和檢測問題,並通過模擬證明了我們提出的新檢測器的有效性。
  5. Mimo ; order statistics ; flat fading ; gamma distribution

    Mimo順序統計量平坦衰落gamma分佈
  6. To verify their effectiveness, simulation studies are conducted to test the performance of the proposed turbo codes in awgn channels and flat fading channels. in these simulations, the modified max - log - map decoding algorithm and the golden - spread interleaver are applied

    模擬研究了採用優選擴散交織與改進的max - log - map譯碼演算法的turbo碼在加性白高斯噪聲( awgn )通道以及平衰落通道上的性能。
  7. We propose the joint filterbank precoders and decision feedback equalizers structure at first, by which the dispersive channel is equivallent into parallel independent flat fading subchannels such that the diversity gain of the receiver is increased. then we adopt the discrete - time ( dt ) canonical model to convert the problem of blind signal processing of tv dispersive channels into processing the time - invariant multi - channels model blindly, and discuss the problem of blind equalization and identification of tv dispersive channels based on this new model

    第一種是採用濾波器組聯合均衡方法將色散通道等價為一組獨立的平坦衰落子通道,以提高接收機的分集增益;另外一種是提出採用離散正則模型將時變色散通道的盲信號處理轉化為時不變多通道模型的盲信號處理,並針對該模型對時變色散通道的盲均衡與盲辨識方法進行了詳細討論。
  8. 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。
  9. The problems of carrier frequency offset estimation under the condition of the agwn channel, frequency flat - fading channel and frequency selective - fading channel are studied in detail respectively

    本文仔細研究了在高斯白噪聲通道下、頻率平坦衰落通道下和頻率選擇性衰落通道下高精度估計信號載頻偏差的問題,並對相應演算法提出了一些改進辦法。
  10. Statistical distributions of mimo channels over flat fading

    平坦衰落mimo通道的能量統計特徵分析
  11. This method can convert the dispersive channels into independent flat fading subchannels, so that it increase the diversity gain of the receiver and outperform that of the original paper as for the ber performance and maximum mutual information while maintaining all the advantages of it. in chapter 4, the models of the tv dispersive channels are reviewed in signal processing perspective

    在第四章中,作者對時變色散通道的信號處理模型進行了研究,提出了離散正則模型的概念,對其進行了詳細的討論,並利用多采樣率理論將該模型推廣到一般的時變色散通道。
  12. Autoregressive modeling for flat fading channel simulation

    模型的平坦衰落通道模擬
  13. Subsequently the channel was modeled for three types namely additive white gaussian noise, flat fading and frequency selective fading. lastly, the receiver was studied

    接下來通道建模成三種不同的類型,即加性高斯白噪聲通道、平坦衰落通道和頻率選擇性衰落通道。
  14. Based on the research of mimo detections under the flat fading channel, this paper focuses on the mimo detection under the frequency selective fading channel, chiefly aiming at the lll detection algorithm

    在對平坦衰落通道下mimo檢測技術研究的基礎上,本文展開了對頻率選擇性通道下mimo檢測技術的研究。
  15. With the downlink simulation model constructed, performance of wideband cdma under different radio propagation environment and vehicular speed is simulated. based on system model of mc ds cdma under flat fading channel with relative shifts of spreading sequences within 1 chip and frequency selective fading channel with arbitrary relative chip shifts, performance of multicarrier cdma system with go sequences under different radio environment is investigated

    基於多載波直接序列碼分多址在乎坦衰落通道中序列偏移小於1個碼片及在頻率選擇性衰落通道中偏移任意個碼片的系統模型,本文還分析了採用廣義正交序列的多載波碼分多址系統在不同無線傳播環境下的性能。
  16. Finally, performance of adaptive modulation and coding in 11sdpa system is investigated. multi - code channel structure of physical layer, coded modulation schemes and adaptive transmission parameter selection are analyzed. simulation implementation of fading compensation in flat fading channel and maximum ratio combining ( mrc ) in frequency selective fading channel is investigated

    最後,本文還研究了hsdpa中自適應調制與編碼性能,分析了物理層多碼通道結構、編碼調制方案、自適應傳輸參數選擇,並研究了平坦和頻率選擇性衰落通道中衰落補償和最大比合併( mrc )的模擬實現。
  17. 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。
  18. 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 ) 。
  19. 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。
  20. While this dissertation will use wavelet analysis to decompose fading - process, and provide wavelet model of flat fading channel, then propose a new blind receiver based on monte carol algorithm

    本文將平衰落通道的衰落過程進行小波分解與建模,在此基礎上提出一種採用順序蒙特卡羅演算法的盲均衡接收機,並給出了模擬結果以證明此接收機的優異性能。
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