time frequency modulation 中文意思是什麼

time frequency modulation 解釋
時頻調制
  • time : n 1 時，時間，時日，歲月。2 時候，時刻；期間；時節，季節；〈常pl 〉時期，年代，時代； 〈the time ...
  • frequency : n. 1. 屢次，頻仍，頻繁。2. （脈搏等的）次數，出現率；頻度；【物理學】頻率，周率。
  • modulation : n 調整，調節；（聲調的）抑揚，變化；【音樂】轉調，變調；【無線電】調制。 amplitude modulation 振...
  1. On the base of researching the theory of the scheme and analyzing the signal feature, it is obtained that the existence manners and character of distance information in the differential frequency signal. at the same time, a new conclusion is gained that the technology of frequency agility can decrease the constant error of system. it is also to say that frequency agility and frequency modulation fixed - distance fuze has the similar feature to random period frequency modulation fixed - distance fuze. according to the theory of address coding in the hopping - frequency communication, the paper presents the principle of selecting the frequency agility sequence which fit to the radio fuze and constructs the frequency agility sequence family based on the rs codes

    在深入研究方案原理和分析信號特徵的基礎上，獲得了該體制引信差頻信號中，距離信息的存在形式和特點，得出了頻率捷變技術的引入降低了系統定距固定誤差這一新的結論，即頻率捷變調頻定距引信在定距性能上具有類似隨機周期調頻定距的特徵。本文引入跳頻通信地址編碼理論，結合無線電引信的具體特徵，提出了適用於無線電引信的頻率捷變序列的選擇原則，並構造了基於rs碼的寬間隔頻率捷變序列族。
  2. The modulation of sound properties over a wide range of time scales is one of the most obvious characters of oscine passerine ' s vocal, whose song contains many different kinds of syllables that consist of many more multiple song phrases. in oscine passerine, ipsilateral projections of ra to nxiits innervates the ipsilateral syringeal muscles exactly, and thus they have strong ability of vocal control with variable tones, high frequency and higher lever of quality. as a result, the songs sound well

    鳴禽鳴囀的最大特點之一便是其單次鳴唱時間長，鳴唱所包含的音節數量和音節種類繁多，因而由這些音節所組成的句型結構也是復雜多樣富於變化，且由於nxiits嚴格的側別控制（每一側核團只支配同側鳴肌） ，使其具有更強的控聲能力，其鳴聲音調變化幅度大，頻率高，品質因數大，音色好，因而其鳴聲也悅耳動聽。
  3. The pulse code modulation / frequency modulation ( pcm / fm ) is widely used in most reentry remote sensing ( rrs ) system at the present time in our country

    目前我國再入遙測系統主要採用脈沖編碼調制/調頻（ pcm / fm ）體制。
  4. In view of this situation this article has conducted research to the design of metallurgy auxiliary biography with the frequency conversion table electrical machinery first multianalysis to the frequency changer and the frequency conversion table electrical machinery movement characteristic is carried out, the voltage waveform harmonious which the frequency changer outputs is big, attacks in a big way, and the voltage climbing rate reaches as high as 6600v / mu s which is 20 times ordinary sine alternating voltage, the rolling mill auxiliary biography table set the extremely strict request to the electrical machinery ; its movement frequency is very low, rate frequency in 8 - 20hz ; the velocity modulation scope is wide, the lowest movement frequency lowers to 1hz, and the starting number of times is quite frequently, each hour reaches as high as 600 - 800 time, the impact shoulders in a big way, the overload capacity request is high

    針對這一情況本文對冶金輔傳用變頻輥道電機的設計進行了系統研究。首先對變頻器和變頻輥道電機的運行特性進行詳細分析，變頻器輸出的電壓波形諧波大，沖擊大，電壓上升率高達6600v / s ，是普通正弦交流電壓的20倍;軋機輔傳輥道對電機提出了十分嚴格的要求:其運行頻率很低，額定頻率在8 - 20hz ;調速范圍寬，最低運行頻率低到0 . 5hz ，起動次數相當頻繁，每小時高達600 - 800次，沖擊負荷大，過載能力要求較高。
  5. Large time - band product signals such as linear frequency modulation signals ( lfm ), nonlinear frequency modulation signals ( nlfm ), phase coded signals and so on are one of key technologies for pulse compression radar systems

    具有大時寬帶寬積的信號，如線性調頻信號、非線性調頻信號、相位編碼信號等是雷達應用脈沖壓縮技術的關鍵之一。
  6. Pulse compression technique is widely used in modern radar systems. it solves the contradiction between the range and velocity resolution. large time - bandwidth product signals such as linear frequency modulation signals ( lfm ) are used in pulse compression technique to improve the resolution in range domain

    現代雷達系統廣泛採用脈沖壓縮技術，在確保雷達作用距離和速度分辨力的前提下，採用大時帶積脈沖壓縮信號:如線性調頻（ lfm ）信號提高距離分辨力。
  7. Chirp signal is a kind of pulse - compressed signal with large time - bandwidth products achieved through linear frequency modulation. it has high resolution in range because of its great bandwidth

    線性調頻信號是通過線性頻率調制獲得大的時寬帶寬積的一種脈沖壓縮信號，具有大的帶寬，因此有高的距離分辨力。
  8. This system can process linear frequency modulation signals ( lfm ), nonlinear frequency modulation signals ( nlfm ) and taylor quadriphase code signals with time width under 42 s and band width under 5mhz. the experimental results demonstrate that the specification characteristics meet the requirements of practical radar systems

    該系統可處理時寬在42 s以內?帶寬在5mhz以下的線性調頻信號（ lfm ） ，非線性調頻信號（ nlfm ）和taylor四相碼信號，且技術指標完全滿足實用系統的設計要求。
  9. 3 using current injecting frequency modulation method and modulating sine wave around the resonator point, the lock - in phenomena is observed in a comparatively short period of time. this has achieved the basic goal for a closed loop r - fog

    3 、採用電流注入法，在諧振點附近進行正弦調制，實現了對諧振點的短時間鎖定，達到了閉環光纖陀螺設計的首要基本要求。
  10. And the waveform of the transmitted signals was designed based on the target distance ( 5 ~ 50m ). the waveform is triangular fmcw with central frequency at 6ghz, modulation bandwidth 100mhz, modulation period 10 s, step frequency 0. 2mhz, and step time 10ns

    在此基礎上，設計發射信號波形參數為三角形調頻連續波，中心頻率6ghz ，調制帶寬100mhz ，調制周期10 s ，步進頻率0 . 2mhz ，步進時間10ns 。
  11. Green - mode which provides off - time modulation to linearly decrease the working frequency under light - load conditions and power limiting which will turn off the transistor when peak current of inductor reaches the threshold current

    同時該電路集成了能在輕負載情況下自動降低頻率的綠色模式以及能在電感峰值電流過高時關斷調整管的功率限制模塊，降低了系統的功耗。
  12. So long distance and high frequency modulation cannot exist underwater at the same time.

    在水下遠距離和高頻調制不能共存。
  13. The anti - jamming performance of the modem is greatly improved by time - frequency modulation according to the applying case

    根據該數據機的應用場合，它採用時頻調制的方法使其抗干擾能力大大提高。
  14. By experimentation, it is shown that time - frequency modulation is efficient and effective, which has rake and fault tolerant capacities in passband. the modem has strong ability of anti - jamming and error - correction which can finish the mission of communication under poor channel qualitative properties

    經過實驗證明，時頻調制是一種簡捷有效方法，它具有很好的帶內分集接收效果和容錯能力，該數據機在通道質量很差的條件下，仍能完成數據通信的任務，具有很強的抗干擾和糾錯能力。
  15. 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。
  16. Simulations on light intensity are validated by experiments and influence of mechanical dither on gyro frequency stabilization is studied for the first time. then it is point out that the key to improve the precision of frequency stabilization is to choose appropriate modulation frequency based on the frequency spectrum of sharp pulses, which is introduced by mechanical dither. thereafter, experiments of frequency stabilization under different modulation frequencies are made

    通過實驗驗證了光強模擬結果，首次分析了機械抖動對穩頻的影響，指出提高機抖陀螺小抖動穩頻精度的關鍵在於：根據機械抖動引入的交流光強尖峰脈沖頻譜分佈選擇合適的調制頻率，並給出了不同調制頻率的穩頻實驗結果。
  17. After the compensation based on the rule of the minimum entropy, the resolution of the cross - range image is lower as the large size and non - uniform rotation, which cause the image to be not right at all sometimes. in order to eliminate effect of the non - stationary rotation, the first order approximation and relax algorithm are adopted to search the initial frequency, amplitude, frequency modulation rate and obtain the dynamic image of the target at any time

    分析了低分辯雷達的成像演算法，建立在最小熵補償基礎上的演算法得到的橫向像的解析度仍然比較低，尤其對大的目標和機動目標，為此我們採取了一階近似的relax演算法搜索目標的初始頻率、幅度、解調率從而獲得目標的動態一維像，模擬數據和試驗結果證明該方法是有效的。
  18. The relative motion between the base station and the mobile results in random frequency modulation due to different doppler shifts on each of the multi - path components, also called time selective fading

    由於基站與移動臺之間的相對運動，每條路徑都會有一個明顯的多普勒頻移，導致通道的隨機頻率調制，也稱時間選擇性衰落。
  19. Then on one hand, author makes researches of anti - jamming against pulse jamming 、 gauss white noise jamming and radio frequency noise jamming from the side of signal processing. author exercises much signal processing knowledge of time - domain sliding window accumulation 、 wavelet analysis 、 time - frequency analysis and linear prediction and carries out many simulation experiments. on the other hand, author proposes the anti - jamming methods of using a sar similar to double - base radar and modulating the amplitude 、 the phase of emission signal and changing the frequency modulation slope from the side of changing sar system model

    作者首先提出了合成孔徑雷達抗干擾的定義、分類以及評價抗干擾方法好壞的主客觀標準；然後，一方面從信號處理的角度出發對脈沖式干擾、高斯白噪聲干擾以及射頻噪聲干擾進行了抗干擾研究，其中運用了時域滑動窗口積累，小波分析，時頻分析以及線性預測等信號處理知識，做了大量的模擬實驗；另一方面，本文基於改變合成孔徑雷達系統模式提出了利用類似雙基地雷達來抗干擾，以及對發射信號進行調幅、調相以及改變調頻斜率來抗干擾，同樣做了相應的模擬實驗。
  20. This is by two reasons : the first, as the development of military communication technologies, it transit from digital to software implementation, intelligence, broad band implementation and network implementation. many new technologies such as adaptive frequency hopping, burst communication, broadband modulation and complex coding accelerate the research about pertinence algorithms of signal sense and signal processing. the second, three hotspots of modern signal processing - spectrum estimation, high - order statistics ( hos ) and time - frequency analysis theory become more and more consummately and being used in communication jamming and anti - jamming field

    應用於軍事通信對抗的信號處理理論發展非常迅速，這得益於兩個方面的動力：其一，軍事通信的技術和手段不斷更新，在數字化的基礎上逐步走向軟體化、智能化、寬帶化和網路化，出現了自適應跳頻、突發通信、寬帶調制和復雜編碼等新的實用技術，推動了具有很強針對性的信號偵測和處理領域的演算法研究；其二，現代信號處理的三大熱點? ?譜估計、高階統計量方法、時頻分析的理論和技術日臻完善，並逐漸應用於通信對抗領域。
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