flat fading channel 中文意思是什麼
flat fading channel
解釋
平坦衰落通道-
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。 -
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。 -
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。 -
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。 -
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。 -
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。 -
Finally, the application of mud in the frequency - flat slowly fading multi - path channel is introduced, and to enhance the system efficiency the joint use of the rake receiver and mud is applied in the frequency - selective slowly fading multi - path channel
最後，在討論了平坦慢衰落通道的基礎上，將rake分集技術和多用戶檢測技術相結合應用於多徑的頻率選擇性慢衰落通道，以達到改良系統的性能的目的。 -
Autoregressive modeling for flat fading channel simulation
模型的平坦衰落通道模擬 -
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。 -
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。 -
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。 -
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。 -
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 ） 。 -
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。 -
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。 -
The fourth part considered how to improve system performance by adopting transmission diversity in flat fading channels. in the traditional space - time trellis code design, the space diversity, time diversity and channel code are concerned together to get best space diversity, time diversity and code gain
傳統的空時格碼把空間分集、時間分集和前向糾錯編碼聯合設計，以n摘要獲得最大的空間分集、時間分集、通道編碼的增益。 -
At present, the research on the mimo detections under the flat fading channel has been maturational. this paper firstly overviews and simulates three practical mimo detections, which are zero - forcing ( zf ) algorithm, v - blast algorithm and lattice - reduction aided ( lll ) detection algorithm. the simulation results suggest that lll algorithm has apparent advantages over other two detection algorithms
目前，對于平坦衰落通道下的mimo檢測技術的研究已較為成熟，本文首先對其中三種具有較高實用性的演算法進行了綜述和模擬研究，其中包括迫零檢測、 v - blast檢測和格約簡輔助檢測三種演算法。 -
Adaptive modulation mainly include several problem for example signal shape, channel estimation, all digital receiver and so on. since the channel referring to adaptive modulation is very hostile in wireless transmission channel, its algorithms and architectures used for the modulation and demodulation should be carefully devised and considered. designing appropriate algorithms and architectures of the adaptive modulation are main research goal of this paper to meet the need of flat fading channel and selective fading channel
自適應調制技術主要包括信號成形、通道估計和檢測、全數字接收等方面的問題，由於自適應調制所涉及的通道是非常惡劣的無線傳輸通道，其調制與解調的演算法和結構必須加以精心的設計和考慮，針對具體所假設的平衰落和選擇性衰落的無線通道情況來設計自適應調制系統的演算法和結構是本文研究的主要方向。 -
So far, there is not much research on the signal detection of da - mimo system, and the general frequency selective channel is not taken into consideration. in chapter 3 of this dissertation, the coherent signal detection algorithms for da - mimo system under both flat fading and frequency selective fading channels are derived. and the analysis of the factors which affect the performance of the detection algorithms is also illustrated through computer simulations
針對分佈mimo信號檢測目前研究較少，並且沒有考慮一般意義下的頻率選擇性通道的情況，本文在第三章分別推導了基於平坦衰落和頻率選擇性衰落通道環境的分佈mimo信號相干檢測演算法，並通過計算機模擬，對影響演算法檢測性能的因素進行了分析討論。
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