頻移制 的英文怎麼說
中文拼音 [bīnyízhì]
頻移制
英文
frequency shift system-
1 m 0. 5, the phase - shifted angle 6 is controlled in term of sine law which makes the magnitude of resonant voltage track a reference sine voltage, and the resonant voltage is rectified, filtered, inverted and then the better sine - voltage output is obtained, theoretical analysis and experimental results show that for the resistive load and inductive load, the switches of leading leg of the phase - shift - controlled circuit are always turned on at zvs, and ones of lagging leg are turned on at zvs ( < 0 ) or turned off at zcs ( ( > 0 ), moreover, all switches in the low - frequency inverter are always turned on and off at zvs, the measured circuit efficiency for rated load reaches up to 88 %
從功率單向流動角度出發，提出了一種lcc諧振型恆頻移相單相高頻鏈逆變電路拓撲，在調制系數0 . 1 m 0 . 5情況下，控制移相角按正弦規律變化，使諧振電壓脈沖列的幅值追蹤參考正弦電壓信號，經過整流、濾波、低頻逆變，從而獲得正弦度較好的輸出電壓。理論分析和實驗結果證明對于阻性負載或阻感性負載，移相全橋具有超前橋臂零電壓開通，滯后橋臂或者零電壓開通（ _ 0 ）或者零電流關斷（ _ 0 ）的軟開關特性，而低頻逆變器的各個開關均實現零電壓條件下的開通與關斷。Based on the doppler effect and pulse coherence technique, synthetic aperture radar ( sar ) breaks through the azimuth resolution limitation imposed by real aperture antenna. in combination with the pulse compression technique, two - dimensional high resolution imagery to distant targets can be realized
合成孔徑雷達（ sar ）利用以多普勒頻移理論和脈沖相參為基礎的合成孔徑技術，突破了實孔徑天線對方位向分辨力的限制，與脈沖壓縮技術相結合，實現了遠距離目標的二維高分辨成像。The equation including the nonlinear dispersion, i. e. the modified nonlinear schrodinger ( mnls ) equation, is a better model. in this thesis, we take mnls solitons as a model for femtosecond soltions. then based on the recently developed direct perturbation theory for perturbed mnls equation, we study the raman self - frequency shift of femtosecond solitons and its suppression by the means of frequency filters. for this purpose, first, we define the physical parameters of mnls solitons ; next, through the direct perturbation theory for perturbed mnls equation, under adiabatic approximation, we obtain the evolving parameters of mnls soliton on our questions and then choose the parameters of frequency filters based on it ; at last, we directly numerically simulated our questions by split - step fourier ( ssf ) method after improving the arithmetic of the differentiation of the nonlinear item for satisfying mnls equation
本論文以mnls孤子作為光纖飛秒孤子的模型，通過新近建立的mnls孤子直接微擾理論，研究光纖中由拉曼效應引起的飛秒孤子在傳輸中的自頻移，以及通過頻率濾波對自頻移的抑制。為此，首先給出描述mnls孤子的各物理量，然後用mnls孤子直接微擾理論，解析地得到這些問題絕熱近似下的孤子參數演化，並由此選擇頻率濾波的參數，最後用分步傅里葉方法，在對非線性項微商的演算法做出了適合於mnls孤子的改善後，對拉曼效應及頻率濾波進行了直接數值模擬，其中頻率濾波參數用微擾理論確定。Our treatment shows in the raman effect case, mnls solitons, the same as nls solitons, keeps its energy, initial center and initial phase unchanged. however, the raman effect, not the same as nls solitons. reduces its amplitude, widens its width and under the same conditions, the self - frequency shift of mnls soltions is closer to the result of numerical simulation. in the raman effect together with frequency filters case, mnls solitons, the same as nls solitons, keeps initial center and initial phase unchanged and bandwidth - limited frequency filters can make the mean frequency of mnls soltion stand a steady value at the red side of the initial mean frequency, i. e. suppress the self - frequency shift of mnls soltions. and that, the other physical parameters of mnls soltion last stand a steady value. however under the same conditions, the steady value of the mean frequency of mnls soltions is closer to the initial mean frequency and the result of numerical simulation
有所不同的是， raman效應雖然不改變孤子能量，但會引起孤子峰值的下降和寬度變寬，且在同一條件下， mnls孤子微擾理論得到的自頻移比nls孤子微擾理論得到的更接近直接數值計算結果。有限帶寬的頻率濾波也不引起mnls孤子初始中心、初始位相的改變，選取適當的頻率濾波器參數值能使孤子的平均頻率穩定在初始平均頻率的紅側一穩定值，抑制了自頻移，而且孤子的各物理量最後都穩定在一穩定值，這些與nls孤子微擾理論都是類似的。有所不同的是，寬度為飛秒量級下， mnls孤子平均頻率的穩定值更接近初始平均頻率，更接近數值計算結果。This thesis analyzed the error performance of mfsk and mpsk modulator in hf with optimal receiver, studied the shortcoming and strongpoint of several typical short - wave data transmission systems and their performance over fading and intersymbol interference channels. the theory and key technical of adaptive modem is discussed. in the last, an efficient modulation scheme - block coded modulation is introduced into hf radio systems to improve the efficiency of hf data transmission, this paper also proposes a hf data transmission system scheme composed of a block coded modulator and a decision feedback type adaptive equalizer
本文在對短波數傳兩種常見調制方式fsk及psk最佳解調性能分析的基礎上，討論了幾種採用典型調制技術的短波數傳系統（如時頻調制、多進制頻移鍵控慢跳頻、 chess系統）原理、優缺點以及抗衰落和抗符號間干擾的性能；分析了自適應串列數傳系統抗短波通道衰落和多徑干擾的原理、關鍵技術；在本文的最後引入一種有望解決短波數傳系統低效率狀況的調制方式bcm -分組編碼調制，給出了一個採用bcm技術與自適應均衡技術相結合的短波數傳系統方案，並通過計算機模擬進行了初部驗證。Recently, anodic aluminum oxide ( aao ) membranes with a regular porous structure have been prepared by electrochemical methods and have widely been used to produce various nanostructured materials within highly ordered channels in the aao membrane in which the diameters and lengths of the inserted nanowire can be well controlled. in this dissertation, after reviewing the latest development in research of the novel system of nano - array composite by using template method, reports my research work of fabricating metal / aao nano - array composite and their novel optical properties in the past few years. different metal / aao composites ranging in volume fraction of the metal showed unusual size - dependent optical properties, some important results obtained are as following : 1
接著論文全面總結了作者近幾年以金屬aao納米有序陣列復合結構光學特性為選題的研究工作：進一步優化了制備金屬aao納米有序陣列復合結構的工藝參數，較系統地考察了分別由幾種不同金屬（ co 、 ni 、 ag 、 cu ）植入aao模板后，合成的納米有序陣列復合結構樣品的光反射、透射和吸收等一般光學特性，還專門研究了各系列結構樣品吸收邊的頻移、金屬納米粒子表面等離子激元共振吸收特性，以及特殊的半導體光學特性等。The main works and results we have accomplished are as follows : 1 ) red - detuned locking of cooling / trapping laser to the cycling transition of cesium cooling has been accomplished by means of a double - passed acoustic - optical frequency shifting system and the technique of saturated absorption spectroscopy. the short - term residual frequency jitter is less than 350khz ; 2 ) automatic controlling system by computer programs has been established for laser cooling and trapping and cavity qed experiment. the laser and magnetic fields can be controlled by the acoustic - optical modulator and the electronic - controlled logic gate respectively
具體如下： 1 ）採用了往返兩次通過的聲光頻移系統結合飽和吸收光譜技術的實驗方案，實現了冷卻俘獲激光頻率相對于銫原子冷卻循環躍遷的負失諧鎖定，短期頻率穩定度約在350khz以內，並可方便地調節其負失諧量而無須對后續光路再作調整； 2 ）建立了一套基於計算機程序控制的、銫原子激光冷卻與俘獲實驗所需的時序控制系統。This dissertation, basing on simulation, makes a deep research on simulating signal of gmsk ( gaussian filtered minimun frequency shift keying ) baseband modulation and demodulation in ais ( automatic identification system ) equipment. the technology related in the following makes the modulation and demodulation of baseband signal into realization by ti dsp, at the same time, provides a key technique to develop ais system inland
本文著重對自動識別系統（ ais - automaticidentificationsystem ）設備的高斯濾波最小頻移鍵控（ gmsk - gaussianfilteredminimunfrequencyshiftkeying ）基帶調制解調信號進行了模擬研究，並在模擬的基礎上，在ti的dsp上實現了基帶信號的調制解調，為國內研製ais系統儲備了關鍵技術。Secondly, basing on the theory of on - off gain of small signal, the raman gain coefficient for frequency shift between 0. 5 and 20 thz of standard sigle mode optical fiber is measured by pump - probe method through a super luminescent diode ( sld ) as a broadband small signal probe source. thirdly, numerical simulation analysis of gain characteristic of raman fiber amplifier for c band wdm signal light is made according to the raman gain coefficient of the fiber measured before through target and four rank runge - kutta method. at the invariability of wavelength and maximum power of each of two pumps, schematic of powers of two pumps for best flatness on c band wdm optical gain was found out, at the same time, the factors of resulting in gain saturation is analyzed, too
本文首先應用經典的電磁理論對拉曼光纖放大器的工作機制進行了分析，然後，根據小信號理論推導出的開關增益求出了光纖拉曼增益系數的表達式，採用泵浦-探測波的方法，利用超輻射激光二極體（ superluminescentdiode簡稱sld ）作為探測光源，測量了所用標準單模光纖頻移為0 . 5 - 20thz的拉曼增益系數，之後根據所測得的光纖的拉曼增益系數譜對應用該類光纖構成的放大c波段wdm光信號的拉曼光纖放大器的增益特性採用打靶法和四階龍格- - -庫塔進行了數值計算，在給定了兩個泵浦光源的波長和最大功率后，找出了反向泵浦情況下使c波段wdm光源增益最平坦的兩個泵浦的各自最佳功率，同時也分析了導致信號光飽和的原因。First, the structure of the second generation ctdrs isl was discussed in this paper, the characteristic of coverage in the second generation ctdrs by the characteristic of orbit and the simulation model of isl was analyzed then the effect of the isl establishing process analyzed. second, the discussing and analyzing focus on the characteristic of signal during the establishing isl process, establishing the orbit model, the technology of doppler frequency shift capturing and tracking sequence and the effect of background noise, then the theory analyzing the parameters we have just mentioned, and this will support the reference for the implement of project. the simulation and test of the isl of ctdrs and analyzing from theoretical basis to implement of simulation were mainly focused in this paper
其中討論了二代中繼星捕獲跟蹤系統星間鏈路的模擬方案的組成結構，利用軌道特性對二代中繼衛星系統的覆蓋特性進行分析，搭建了星間鏈路的模擬模型，其中包括中繼衛星和用戶衛星在內的軌道模型、星間鏈路模型、用戶星信號調制模型等，並對星間鏈路建立過程的影響進行分析;重點針對星間鏈路建立過程的信號特性，軌道模塊的建立、多普勒頻移技術、背景噪聲影響、載波的捕獲與跟蹤技術等進行了實際參數的設計與理論分析。In the future, we will increase the number of the frequency - hopped sub - bands. it will solve the inter - symbol interference ( isi ) perfectly. then the system will be used on the test out of labs
后續的工作只要把十六進制改為八進制（此工作不難）的數字頻移鍵控傳輸系統，藉以提高跳頻的子帶數目，即增加跳頻點，可期適于海上的應用。This thesis studied and introduced the method of msk modulation. it is a special type of constant envelope - continuous phase fsk
本文研究並介紹了msk調制方式，它是包絡恆定相位連續的頻移鍵控的一種特殊情況。Frequency shift keying fsk
移頻鍵控，頻移調制Fsk / psk radar signal is the signal with both fsk and psk modulation at one time. it is with large bandwidth time product ( bt ), thumbtack - like ambiguity function and well ability of anti - emi. the fsk / psk signals of which the frequency - hopping and bi - phase sequences were randomly chosen often have high sidelobe level
Fsk / psk信號是同時進行頻移鍵控（ fsk ）和相移鍵控（ psk ）調制的信號，該信號具有大時帶寬積（ bt ）和高分辨特性，並具有「圖釘型」模糊圖結構、低截獲概率（ lpi ）特性和較好的抗干擾能力，受到了廣泛的重視。Removes interlace artifacts from ntsc or pal video input. will only affect video input with a height of 240 lines or greater. this filter should not be used with non - interlaced video
從輸入的ntsc或pal制式視頻移除交錯。這將對240線或更高的視頻造成（顯著）影響。這個過濾器（濾鏡）對無交錯的視頻可能沒什麼效果。However these converters become more complicate. phase - shift zvs technique has been used in bidirectional dc / dc converters since it can realize zvs for all switches without auxiliary switches. however when the amplitude of input voltage is not matched with that of output voltage, the current stresses and rms currents of the converters become higher, in addition the converters can not achieve zvs under light - load condition
諧振、準諧振或多諧振技術方案，變換器的電壓電流應力較高，變頻控制增加了濾波器設計的難度；能量緩沖吸收電路或有源鉗位電路方案，由於需要增加多個額外輔助元件，增加了變換器的復雜性；全橋相移技術方案，由於主電路無需增加額外元件，只需利用相移控制，即可實現軟開關，因此引起關注。Firstly, according to the characteristic that the doppler frequency shift signal can be approximated as a single sinusoid signal, the extended sinusoid signal retrieval ( pisarenko and esprit ) methods are presented and signal state and measurement formulations are developed, so the kalman filter recursive method is got. the brief introduction of low velocity moving target doppler frequency shift signal wigner - ville transformation and wavelet transformation expression are presented in this paper. secondly, because the clutter is gaussian distribution, cumement and high - order spectrum based methods are presented and the simulation results prove their good performance to suppress gaussian clutter in low velocity moving target doppler frequency shift signal processing
一個方面是根據低速目標的多普勒信號可簡化為單一正弦波形式這一特點，得到了擴展的高斯色噪聲背景下的諧波恢復演算法，即高斯色噪聲中的pisarenko諧波恢復法和旋轉因子不變法（ esprit ） ；並推導了信號的狀態方程和觀測方程，進而得到基於卡爾曼濾波的遞推演算法對信號進行提取；本文還簡單的介紹了低速運動目標的多普勒頻移信號的wigner - ville變換與小波變換；另一個方面是針對雜波服從高斯分佈這一特點，提出了對接收信號求累積量和高階譜來對高斯雜波進行抑制。The fsk is used in the modulation for audio signals and the data signals. and the fdm is used to merge three lines signals
頻移鍵控用於音頻和數據信號的調制，三路信號的混合採用了頻分復用技術。So the acoustic wave is the only practical solution in this channel. an underwater acoustic channel is characterized as a multi - path channel due to signal reflections from the surface and the bottom of the sea. because of wave motion, the signal multi - path components undergo time - varying propagation delays that result in signal fading and inter - symbol interference ( isi )
本文從分析淺海水聲通道的傳輸特性入手，針對多途徑效應引起的幅度衰落及碼間干擾問題，提出一種適用於水聲e - mail通信的十六進制（或八進制）數字頻移鍵控（ mfsk ）傳輸系統。Long - range underwater acoustic information transmission through mfsk modulation
基於多進制頻移鍵控調制的水聲遠程信息傳輸技術研究分享友人