非時變通道 的英文怎麼說
中文拼音 [fēishíbiàntōngdào]
非時變通道
英文
time invariant channel- 非 : Ⅰ名詞1 (錯誤) mistake; wrong; errors 2 (指非洲) short for africa 3 (姓氏) a surname Ⅱ動詞1 ...
- 時 : shí]Ⅰ名1 (比較長的一段時間)time; times; days:當時at that time; in those days; 古時 ancient tim...
- 通 : 通量詞(用於動作)
- 道 : Ⅰ名詞(道路) road; way; route; path 2 (水流通過的途徑) channel; course 3 (方向; 方法; 道理) ...
- 通道 : thoroughfare; passageway; pass; enterclose; gallery; drong; tunnel; avenue; alure; way; row; key ...
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The ionosphere is a complex medium, which is aeolotropy, asymmetry, dispersive and changes randomly with time. in order to improve the communication quality of the shortwave that depends on the ionosphere, we should have aknowledge of the current condition of the ionosphere in real time. the backscatter sounding of high frequency can diagnose the real - time channel characters for shortwave communication or hf radar, which is great assistant to shortwave communication and hf radar
電離層是隨機時變,各向異性,非均勻、色散的復雜介質。為了保證依賴于電離層進行的短波通信質量,必須了解電離層的實時狀態信息。高頻返回散射探測可以實時監測與短波通信或高頻天波雷達相關的天波傳播通道的狀態,對短波通信和天波雷達工作起了重要的輔助作用。Upper gastrointestinal series revealed several characteristic findings : dilatation of the stomach and the first and second portions of the duodenum, abrupt vertical compression of the third portion of the duodenum, churning without orderly peristalsis or passage of the contrast medium proximal to the obstruction, and relief of obstruction when the patient was placed in a position that diminished the drag of the mesentery
做上消化道攝影檢查,兩列皆可見胃及十二指腸第一、二部分略顯擴張,至第三部分則突然中斷,顯示有外在壓迫痕跡,致鋇劑流通受阻,同時有逆流的現象;但阻塞並非完全性,將病人變換姿勢,受阻情形立見改善。Biotic or abiotic stimuli can first cause the alteration in apoplastic signaling system ; on the other hand, apoplast provides a convenient pathway for cell - cell communication, and therefore plays a key role in regulation of cell differentiation, organ genesis, and growth development of plants
當植物遭受生物或非生物環境刺激時,可能首先引起質外體信號系統的變化;同時質外體作為植物細胞之間最方便的通道,在細胞間信號傳遞和信息交流上起重要作用,從而成為協調植物細胞分化、器官形成和整體生長發育的決定性因素之一。The major job is manufactured a transmitter, which has three upmixer channels. its function is to up convert the signals from c - band to ka - band. the input local oscillator is provided by a low frequency crystal oscillator which has a good performance of phase noise, through 512 times multiply to ka band. this sysetem is used in the laboratory as transmitter source of the fuze, for the multidimensional objects in practise, which lead to the complexity of the reflect signal, so the amplitude, frequency and the phase of the transmit signals both have a key role in dealing with the reflection signals. therefore, this system requires for both the coherence of the single channel ’ s amplitude, phase and multi channels
本文的主要工作是應用戶要求製作一具有三發射通道的上變頻系統,可以將c波段的微波信號上變頻到ka波段的毫米波信號。系統的本振輸入基頻由一相位噪聲非常好的低頻率晶振提供,經過512次的倍頻放大至ka波段。本系統作為實驗室中引信的發射源,由於目標反射信號具有時變的多維性,反射信號變得極為復雜,在信號處理時,不僅信號幅值、頻率有決定意義而且相位關系也很有決定意義。The future wireless mobile communication systems are expected to provide ubiquitous, high - quality, and high - rate mobile multimedia transmission. however, hostile multipath fading radio conditions give rise to serious inter - symbol interference ( isi ) ; even worse, wireless channel are often time varying, which makes the system more vulnerable and more difficult to track the channel state. orthogonal frequency dvision multiplexing ( ofdm ), which is inherently resistant against isi, has invoked a popular research interest in recent years, and has been a promising candidate technology of the physical layer for future weideband high - date - rate wireless communications. notwithstanding, ofdm is much more vulnerable to errors of both time and frequency synchronization and to that of channel estimation, and how to obtain correct timing and channel estimation efficiently is highly critical to ofdm systems. the dissertation will focus on both of the aspects of ofdm systems mentioned above
但是無線環境的多徑特性造成通信系統中嚴重的符號間干擾,同時無線通道的時變性使得通道特性跟蹤復雜。而正交頻分復用技術( orthogonalfrequencydivisionmultiplexing , ofdm )正是一種解決符號間干擾的有效傳輸手段,因此ofdm技術作為未來寬帶高速率無線通信的物理層候選技術在當前引起了一股研究熱潮。但ofdm系統對定時同步誤差和通道估計誤差非常敏感,如何在ofdm系統中準確快速地實現符號同步和通道估計是至關重要的,本論文將重點針對這兩個問題進行討論。It is shown by structural seismic response of four wavelets that littlewood - paley wavelet is not suitable for structural seismic response, because structural response is too small, meyer wavelet is a better wavelet for structural seismic response, for it ' s structural response is agreement with the finite element method, and also harmonic wavelet, structural response under earthquake is a little bigger than finite element method, structural response under odd exponent wavelet is also bigger than finite element method, this method is very simple by wavelet transform, wavelet transform method is different from old methods, one is with which not only knows the effects of earthquake wave detail frequency - band on structural response, but also considers earthquake wave ' s non - stationary of frequency and time - domain value, another is the second mode shape and higher mode shape response that do n ' t attenuate so fast
通過對這四種小波的結構地震反應分析研究說明: littlewood ? paley小波不適合於用來作結構地震反應分析,因為在littlewood ? paley小波下的結構地震反應太小,不符合實際情況;用meyer小波作結構地震反應分析比較合適,和有限元法的結果比較接近;也可以用諧波小波來作結構地震反應分析,只是在諧波小波下的結果略為偏大;單邊指數小波下的結構地震反應分析比有限元法稍大一點,它通過小波變換大大簡化了結構地震反應分析。用小波變換方法來進行結構地震反應分析和以往方法不同的是:它不僅可以知道地震波的具體頻率段對結構反應的影響,而且同時考慮了地震波的幅值非平穩性以及頻率非平穩性;另外與以前方法得到的結果有差異的是,第二振型及以後的高一點的振型的反應沒有以前的方法衰減得快。However, this technology is extremely expensive ; one tunnel can use the combined output of 25 fission reactors
但是這項技術非常昂貴;一個量子通道需要25個裂變反應堆同時提供能量。In this dissertation, a kind of linear time invariant systems with unmodeled dynamics and nonlinear uncertainties are considered by using backstepping approach and variable structure control algorithm. also another kind of linear time varying systems are studied based on the same method
本文主要利用backstepping方法與變結構控制方法,研究了有未建模動態及不確定非線性項的線性時不變系統,以及輸入通道帶有干擾的線性時變系統的控制器設計問題Time invariant channel
非時變通道In this thesis, several approaches are studied, including optimal parametric feedforward estimation of fading channels, basis expansion for estimation and equalization of channels, channel estimation based on pilot and data traffic channels and channel estimation using linear interpolation
針對這個問題,本文研究了各種時變衰落移動通信通道的估計與均衡的方法,包括非盲估計的方法、線性內插的方法、基展開的非盲方法和衰落通道最優前饋參數估計的方法。At first, a method for controlling chaos is studied, which is based on phase switching modulation. the n - scroll chua ' s circuit is controlled to its fixed point as well as periodic orbits by using switching modulation on one its phase. its mechanism of control is analysed using the change of the max lyapunov exponent when the system is controlled
首先,通過對多渦卷蔡氏電路中非線性特性函數的相位進行開關調制,把多渦卷蔡氏電路由混沌狀態控制到其平衡態和周期軌道,並用控制后系統的最大lyapunov指數隨時間的轉變闡述了其控制機制。A two - dimensional navier - stokes equation was solved to predict the unsteady, multipassage flow and temperature fields with hot streak in turbine inlet
摘要通過求解二維n - s方程對多通道渦輪級進口有溫度畸變時的流場和溫度場進行了非定常數值模擬。Secondly, the dissertation proposes a novel blind symbol - timing scheme for ofdm systems based on cyclostationarity feature of received symbols. the proposed schemes also exploits the periodicity of ofdm symbol introduced by cyclic prefix, by applying 2 - dimentional fourier transformation and choosing the appropriate correlation peak value as the symbol start location, the precision of this scheme is higher than previous conventional method. thirdly, the dissertation presents analysis with regard to channel estimation of ofdm systems. several interpolation algorithm in ofdm systems which based on pilot sequence have been analyzed in the first instance, and the influence of the channel noise on interpolation precision has discussed. the theoretic analysis and simulation results show that : the interpolation error induced by the precision of interpolation procedure itself has out weight
第三,論文在ofdm系統的通道估計方面,先對基於導頻的ofdm通道估計中的多種插值方法進行了分析,討論了噪聲對插值精度的影響,指出插值本身的精度所造成的插值誤差遠大於噪聲所帶來的插值誤差,從而階次更高的插值演算法在實用中並非最優的;並指出插值濾波法比變采樣率演算法對噪聲的影響更為敏感,在信噪比較高時插值濾波演算法比變采樣率演算法更優。The implementation of such a system is extremely complicated due to three factors : the impulse response of a lrm system have a duration of several hundred milliseconds, the system has to be adaptive, and the adaptation has to be performed with a speech input the traditional adaptive algorithms such as lms and nlms can not obtain the satisfied result in the real - time acoustic echo cancellation processing
但由於聲回授通道的特殊性和復雜性,普通的自適應演算法無法滿足要求,必須採用一些十分復雜的演算法,這樣一來,實時性的問題變得十分突出。快速lms newton演算法的提出,給自適應聲回波對消問題的解決開辟了新的途徑。該演算法集lms演算法的簡單易行性和newton演算法的快收斂性為一體,是一種非常有應用前景的自適應演算法。When there is original stage support only, the load ratio of surrounding rock gets more and more bigger with the increasing of crust stress, correspondingly, the load ratio of initial stage support gets smaller. when the initial stage support and the second support act each other, the load ratio of surrounding rock is more than fifty percent, and it has little change with the increasing of crust stress. the whole analysis of the surrounding rock and support shows that the bottom arch of liner and the feet of liner have serious stress concentration, so do the sidewalls and the foot of a wall of the surrounding rock
通過屈曲理論分析結果對比表明,彈性屈曲和突變失穩分析的結果比非線性屈曲分析的結果要大得多,非線性分析由於考慮了材料非線性和幾何非線性,因而結果與實際接近實際;當只有初期支護時,隨著地應力的增加,圍巖的荷載分擔率增大,相應地,初期支護的荷載分擔率就減小了;當有初期支護和二次襯砌共同作用時,圍巖的荷載分擔率在50以上,這一分擔率隨地應力的增加其變化不大;支護和巖體的整體分析表明,襯砌底拱及拱腳處應力集中嚴重,隧道巖體側墻及墻角圍巖的應力集中也較大。So the conductive behavior in ac field was equivalent with the parallel connection of a resistor and a capacitor, the nonlinearity of v - i characteristics originate from a combination of the implication of the nonlinear contribution of tunnel conduction between graphite particles and the production of additional conducting pathways under sufficiently strong local fields, which is the function of the gap between graphite particles and has a relation with the transition ability of electrons
導電瀝青混凝土的導電行為則可用隧道效應進行分析,交變電場中的導電行為可等效為電阻r和電容c並聯,非線性v - i特性產生於隧道效應時粒子間的非線性導電和高電場時誘發額外的導電通路,二者是粒子間隙的函數,與電子躍遷能力有關。However, the administration of distribution is very much difficult in actual and subjected to many elements effects, such as, being difficult to formulate the distribution plan, being difficult to the selection of distribution way, being difficult to deliver goods on time, the evaluating criterion not definite, driver work time not sure, easily fatigue, loss and damage of goods in the process of distribution ; meanwhile, distribution, still is subjected to many un - controlled elements effects in the process of operation, for example, the distribution areas of client communication networks in way the limitation of vehicle passing through service time requirement change of stream of cars and so on
然而現實當中物流配送管理非常困難,受到許多因素的影響,如難以制訂配送計劃、難以選擇配送路徑、難以按時交貨、配送績效評價基準不明確、司機工作時間不定、易疲勞以及貨物在配送過程中的遺失和損壞等;與此同時,物流配送在操作的過程中,還受到許多不可控因素的影響,如客戶的分佈區域、道路交通網路、車輛通行限制、送達時間要求、車流量變化等,為此必須加強物流配送系統的規劃和設計。分享友人