speed of fading 中文意思是什麼
speed of fading
解釋
衰落速度-
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。 -
The videos, voices, data combined traffic and high speed data are becoming more and more predominent in the future, and how to efficiently transfer this multi - medium integrated - data is one of the researcher ' s interesting field. the cdma system, which has striking advantages of anti - multipath fading, soft capacities and large capacities over fdma and tdma systems, has been focused by all of the countries
未來信息社會中，圖象，話音，數據相結合的多媒體業務和高速數據業務量越來越佔主要地位，如何有效地傳輸這種多媒體數據，已經成為移動通信中的研究熱點之一。擴頻技術由於具有抗多徑，軟容量和時分多址與頻分多址更大的容量和優勢，而受到各國研究者的重視。 -
This paper mainly discusses the design principles and chief techniques of a digital accessing system for power - line communication net ( plcn ). the technology of low bit rate speech compression high - speed modem based on plcn adaptive equalization to the channel anti - jamming and anti - fading are applied in this system. so speech tele - control data and tele - protection signals can be transmitted high quality in the band - limited channel
該系統綜合應用了低比特率語音信號壓縮編碼技術、基於電力通信網的高速調制解調技術、信號傳輸的通道自適應均衡技術和抗干擾、抗衰減技術，可在帶限通道中高質量的傳輸語音、遠動數據和遠方保護等信號，具有較高的整體性能。 -
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。 -
On account of the importance of channels, we also discuss the characteristic of time - varying and fast - fading mobile channels and introduce channel modeling and a method of high - speed simulation for fading channels by using table look - up technique. in addition, because these approaches are simulated on the basis of 3rd generation partnership project ( 3gpp )
由於通道在研究時變衰落移動通信通道的估計與均衡中缺一不可，文中還討論了衰落通道的統計特性和動態特性，快速衰落時變通道的建模和一種使用查表法的快速通道模擬的演算法。 -
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。 -
With increase of heat treatment, agx photochromic glass ' s value of saturation darkening degree higher and fading speed lower
隨著熱處理溫度的提高， agx光致變色玻璃的飽和暗化度增大而復明速率減慢。 -
Concerning with the direct sequence ( ds ) cdma system, this thesis focuses on several issues related to orthogonal spreading sequences and amc, including correlation properties of orthogonal variable - length spreading sequences and their effects on ds cdma system performance, performance of multicarrier ( mc ) ds cdma system with generalized orthogonal ( go ) sequences, adaptive modulation with throughput maximization, performance of adaptive turbo - qam coded modulation in generalized fading channel and performance of amc in wcdma high speed downlink packet access ( hsdpa )
針對直接序列碼分多址（ dscdma ）系統，本文主要研究了正交擴頻序列和自適應調制編碼若干問題，包括正交變長擴頻序列的相關性及其對dscdma系統性能的影響、採用廣義正交（ go ）序列的多載波直接序列碼分多址（ mcdscdma ）系統性能、吞吐量最大化自適應調制、自適應turbo - qam編碼調制在廣義衰落通道中的性能，以及wcdma下行分組接入（ hsdpa ）中自適應調制與編碼性能五個方面。
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