doppler shift 中文意思是什麼
doppler shift
解釋
電子 光學-
The cosmological redshift is not a normal doppler shift
宇宙學的紅移並不是平常的都卜勒偏移。 -
Snr estimation scheme and its application in doppler shift estimation in mobile communication systems
寬帶移動衛星通信通道的研究 -
2. based on watterson model, this paper concentrates on the realization of doppler shift and doppler spread based on dsp
2 .針對watterson通道模型，著重研究了多普勒頻移與多普勒擴展在dsp中的實現方法。 -
The sixth chapter studies the techniques in measuring the bearings changing rate and centrifugal acceleration, and poses several algorithms of measuring pulse doppler shift frequency changing rate. to sum up, this paper studies the key problems in soplat based on particle kinematics and some solutions to them
總而言之，本文系統地研究了基於質點運動學的單站無源定位與跟蹤領域的主要關鍵技術問題並提出了相應的解決方法，其中某些分析結果和方法可直接應用於實際的工程應用。 -
By complementing the proposed scheme with methods to estimate the fractional code delay, the acquisition unit an provide high quality delay estimates such that it can instead of the delay locked loop in the traditional ds receiver. after dispreading successfully, this dissertation introduces a method to estimate the doppler - shift directly from some samples based maximum likelihood estimation, and then revise it forwardly
在成功解擴之後，本文利用最大似然估計從l個樣點中直接估計出殘余多普勒頻偏，並進行前向頻偏校正，來代替傳統擴頻接收機中的科斯塔斯環，經模擬證明該方法的估計精度完全滿足解調的要求。 -
The data analysis has to compensate for the doppler shift to make any signal as sinusoidal as possible, which helps pull it out of the noise ( with something based on a fourier transform )
數據分析中比較對多普勒偏移進行補償以使信號盡可能地接近正弦曲線，以方便從噪音中提取真正的信號（通過傅立葉變換） 。 -
Ka - band mobile satellite cdma system robust to doppler shift
非靜止軌道衛星通道多普勒頻移特性 -
The research consists of several aspects as follows : the characteristics of uwac is analyzed, including the multi - path effect, the doppler shift effect, etc. then the mathematics " model of uwac is given
研究內容主要包括以下幾個方面： ?分析了多途時間擴展、多普勒頻率擴展等水聲通道的物理特性及水聲通道的數學模型。 -
It mainly includes two parts : the frequency offset caused by the difference of the mobile equipment ’ s transmitting frequency and the nodeb ’ s receiving frequency ; the frequency offset caused by the vehicle of the mobile equipment, which is called doppler shift. accurate frequency offset estimation and compensation is of importance for demodulation
它主要由兩部分構成:由於nodeb （基站）和移動臺晶振本振頻率的不同而產生頻偏;由於移動臺運動產生多普勒效應，引起的多普勒頻偏，在信號功率譜上表現為多普勒頻譜擴展（以後簡稱多普勒擴展） 。 -
Topics include : lorentz transformations, length contraction and time dilation, four vectors, lorentz invariants, relativistic energy and momentum, relativistic kinematics, doppler shift, space - time diagrams, relativity paradoxes, and some concepts of general relativity
題目包括：洛倫茲變換、長度收縮、以及時間膨脹、四種向量、洛倫茲不變數、相對論性能量與動量、相對論性運動學、多普勒位移、空間-時間圖，相對論中的佯謬、和一些廣義相對論的概念。 -
This is found by observing the doppler shift in the frequency of the radio signals broadcast from the satellite.
這是通過觀測衛星所發射的無線電信號頻率中多普勒偏移來確定的。 -
There are two uncertain factor about it : the phase of the pn code and the doppler - shift. after capturing the received signal successfully, the traditional ds receiver always uses a delay locked loop ( dll ) to synchronize the pn code and then uses a costas loop to realize the carrier synchronization. this complex closed - loop structure not only take long time to realize the synchronization, but also has the defect of “ hang up ”
傳統的擴頻接收機通常在捕獲偽碼信號后利用遲早門鑒相的延時鎖定環來實現偽碼的精同步，解擴后利用科斯塔斯環實現載波同步，這種閉環結構不僅同步時間長、結構復雜，而且鎖相環還存在所謂的「 hang - up 」現象。 -
In the traditional polarization diversity and combining scheme, differential mode loop and common mode loop is combined to lock in the phase and frequency of the diversity signals and remove the carrier frequency bias and doppler shift
傳統的極化分集接收方案是將差模環和共模環相結合完成兩路信號的同頻同相鎖定以及多普勒頻率偏移的去除。 -
Influence of doppler shift on narrow - band interference suppression in low - orbit satellite communication
高速移動通信中的多普勒分集技術 -
The author considered great numbers of transmission characteristics of real channel in lms model and properly simplified it according to requirement in the project. the key characteristics in the model include multi - path fading, shadow fading, doppler shift, propagation noise, multi - path delay and and state transform of three status homogeneous markov chain described by lms model, etc. the key characteristics of channel are properly collocated and made to be the evidence theory of hardware implementation
Lms模型考慮了大量的實際通道傳輸特性，結合課題需求，實現過程中對lms模型做了適當簡化，考慮了其中的多徑和陰影衰落、多普勒頻移、傳播噪聲、多徑延遲以及lms模型所描述的三狀態齊次markov鏈的狀態轉換等，對其所描述的主要通道特性適當組合，以此作為硬體實現時的理論依據。 -
Through the analysis of the test data and the new development in the relevant literature, some more realistic models for sea - clutter and multipath propagation is concluded and the simulation is accomplished in the software. they provide the foundation for low - altitude radar target detection & tracking techniques research. in the second part, radar low - altitude target detection & parameters ( elevation - azimuth - range delay - doppler shift ) measure are studied
（海）雜波和目標信號的多徑傳播嚴重影響了雷達低空目標探測與跟蹤的性能，通過分析國內外的有關試驗數據和最新的研究進展，總結出比較接近實際的海雜波和多徑傳播模型，並在有關軟體中實現了海雜波與多徑傳播的模擬，為進一步研究各種低空目標探測與跟蹤測量演算法提供了保證。 -
And then the stability and the stable error response of the dpll are analyzed. there is an obvious doppler shift frequency offset in the received signal with flight at a high speed, in the dissertation the uniform sampling second - order dpll is used to remove the frequency bias for its excellent high - pass characteristic of the error transfer function
由於高速飛行的遙測目標在接收信號中會出現較大的多普勒頻率分量，而典型均勻采樣二階數字鎖相環dpll （ digitalphase - lockedloop ）的誤差函數具有高通特性，所以本文提出一種利用其高通特性來去除多普勒頻率分量的新方法。 -
Simulator presented in this paper provides a direct interface for the test of shortwave communication system, which well represents various features of hf channel such as multi - path delay, rayleigh fading, doppler shift, doppler spread, gaussian noise and impulsive interference, etc. in order to realize the channel simulation for the intermediate frequency signal, we, inspired by the idea of soft - defined radio, bring forward a new design method that the channel simulator consists of several dsp chips
本文研製的模擬器提供介面直接對短波通信系統進行測試，能夠全面反映短波通道的多徑時延、瑞利衰落、多普勒頻移、多普勒擴展、高斯噪聲和脈沖干擾等特性。為了實現對中頻信號的通道模擬，開發出一個結合軟體無線電思想的由多個數字信號處理晶元構成的短波通道物理模擬器。 -
Real - time production of doppler shift with a minimum precision of 0. 1 hz is realized by means of interpolation on the basis of lookup method ; simulation of doppler spread is realized by using the gaussian shaped fir filter and linear interpolation technique. 3
在查表法基礎上結合內插技術，實現了最小精度為0 . 1hz的多普勒頻移的實時產生;運用高斯型fir濾波器結合線性內插技術的方法，實現了多普勒擴展的模擬。 -
In case where long - range communication is needed, spatial diversity blind equalizer ( sdbe ) is an effective way to improve snr and suppress distortion. joint carrier phase recovery with sdbe using second order digital phase lock loop is presented to track the doppler shift, and a kind of quantization method is used to reduce the complexity of the multi - channel algorithm. its performance is very similar to the original one
模擬結果表明，採用二階數字鎖相環的空間分集均衡演算法的跟蹤性能超過了採用一階鎖相環和未加鎖相環的演算法，可有效補償由於水聲通道時變而引入的載波相位快速變化；採用誤差量化的演算法和原演算法的收斂和踉蹤性能都很接近。
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