modulation level 中文意思是什麼

modulation level 解釋
調制電平
  • 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...
  • level : n 1 水平儀，水準儀；水準測量。2 水平線，水平面；水平狀態；平面，平地。3 水平，水準；水位；標準；...
  1. Multi - level quadrature amplitude modulation

    多電平正交調幅
  2. Chaotic switching modulations introduce low - frequency harmonic spectrum of output voltage as random switching modulation. in some case, low - frequency noise ripple offset the effect chaotic switching modulations reduce the level of emi. it indicates that the ccfmfd integrates the advantages of spreading harmonic power at the multiples of the switching frequency and not introducing significant noise ripple at low - frequency range. among all chaotic switching modulations, the ccfmfd is considered as the best choice in applying to dc / dc converter

    與隨機調制模式相同，混沌開關調制模式也引入輸出低頻噪聲紋波，有些情況下低頻噪聲紋波可能抵消混沌開關調制降低emi水平的效果。分析表明： ccfmfd模式具有較好的降低emi水平和引入較小低頻紋波的優點，可以作為混沌調制模式較佳的選擇。
  3. As the step of the color tv ( the second generation ) to the digital tv ( the third generation ) is larger and larger, the research of digital television terrestrial broadcasting ( dttb ) become more and more important in china, we are concentrating on the standard of dttb which is suit for our country after describing and analyzing the technical stipulation and speciality of dttb, this paper compares atsc 8 - vsb with dvb - t cofdm and isdb - t bst - ofdmo the emphasis of this article lies in the technical solution about transferring system, channel coding is important component of dttb, which can resist from the bad circumstances o because of lots of varieties and different performance, channel coding become one of the emphasis of the research work this paper analyzes and researches the theory and performance of the different channel coding particularly, points out an effective theoretic analysis method and computer demo of performance comparison a theoretical method for estimating the performance of concatenated codes is proposed in this paperc this is achieved by combining the performance of single level coding rayleigh fading channel and the character of channel modulation it may be useful to research and development of the future digital television terrestrial broadcasting standard of our country

    通道糾錯編碼是數字電視地面廣播傳輸系統的重要組成部分，是抵禦地面惡劣環境的有效手段。由於通道編碼的種類繁多，性能各異，因此是目前研究工作的重點之一。本文詳細分析和研究了幾種通道糾錯編碼的原理和性能，並針對外碼內碼級聯糾錯結合地面通道瑞利衰落提出了一種有效的理論分析方法和性能的計算機比較演示方案，總結了不同級聯方案的性能特點，對於我國目前的數字電視地面廣播標準的研究和通道級聯糾錯方案的確立及其參數選擇具有一定的參考價值。
  4. A novel sine - triangle modulation method based on equivalent circuit model for three - level pwm voltage source inverter

    基於等效電路模型的新型三電平逆變器載波調制方法的研究
  5. The principle advantages of vcsels over conventional edge - emitting lasers lie in ultralow threshold current, small far - field divergent angle, high modulation frequency, potential for wafer level testing and the ease for single longitudinal mode operation and two - dimension integration. as a result they show considerable promise for applications such as optical fiber communication, parallel optical interconnects, optical information processing and neural networks, etc. a direct coupling theoretical model in quasi - three - dimension for the gain - wave guide vertical - cavity surface - emitting lasers has been created in this paper

    它與傳統的邊發射激光器相比具有更優越的特性，例如，具有極低的閾值、較小的遠場發散角、調制頻率高、易實現單縱模工作和二維集成，無須解理封裝即可進行在片測試等，所以，它被廣泛應用於光纖通訊、并行光互聯、光信息處理、光神經網路等領域。
  6. We analyzed the anti - jam and band inside anti - interfere performance of the system, and the low probability intercept ( lpi ) of the traditional direct sequence spread spectrum ( dsss ) modulations in the uav platform ' s applications. so a new modulation technique using a multi - level pseudo noise ( pn ) code has been presented. the new multi - level pn code is built from a high speed pn code through a low passed filter ( lpf )

    分析了系統抗阻塞式干擾和抗帶內頻帶干擾的性能，以及常規bpsk qpsk - dsss調制在無人機通信中存在的安全隱患，提出了一種用多電平pn碼進行擴頻調制的方法：採用高速pn碼，經過低通濾波器，產生多電平pn碼進行直序擴頻調制，能在低信噪比情況下有效抵抗平方率檢測器對系統載波的檢測。
  7. Chapter 4 focuses on the theory of voltage space vector pulse width modulation ( svpwm ) and its control strategy. a fast space vector modulation algorithm for 3 - level 3 - phase converter is also described in this chapter

    首先，分析介紹了空間矢量控制在三相三電平逆變器控制中的應用，採用了一種簡單的空間矢量演算法，簡化了實時計算。
  8. The following important work has been done : ( 1 ) some special problems of rate - bias laser gyro were analysed. the problems include modulation and demodulation of the output and algorithm of the attitude updates ; ( 2 ) the integrated navigation system with the fault tolerance property which equipped with many navigation equipments as sins, gps, dvs, ads, mg, vg is designed, and compared with that of ckf via simulations ; ( 3 ) the theories and methods of system level fault detection apply to federated filtering is investigated ; ( 4 ) the problem about using the fused information of sins based on rate - bias laser gyroscope / dynamical tune gyroscope to realize the component level hard fault interactions detection through a back - propagation neural network is discussed

    主要研究工作有：研究了速率偏頻激光捷聯慣導的陀螺測量信號的解調演算法；設計了在速率偏頻激光捷聯慣導、 gps 、多普勒雷達、大氣數據系統、磁航向儀及垂直陀螺配備條件下聯邦濾波組合導航系統，對聯邦濾波器和集中濾波器的性能做了模擬對比分析；研究了適用於聯邦濾波器的系統級故障理論和方法；探討了利用速率偏頻激光捷聯慣導撓性捷聯慣導陀螺的混合測量信息，通過神經網路實現硬故障交互檢測的方法。
  9. The processing of these hybrid signals is different from the single modulation signal, that is pulse compression twice. with respect to the hybrid signals including sf, the high range resolution is analysis, and the method for reducing sidelobe level is

    對于與頻率步進信號復合的組合脈壓信號，分析了它們的合成高距離分辨效果，並對其距離旁瓣的抑制方法進行了探討。
  10. In this paper, a novelty space vector pulse width modulation ( svpwm ) technique for the two - phase inverter - fed asynchronous motors system is proposed, which can be widely employed in the low or middle power level field

    本文研究了兩相逆變器-異步電動機系統的svpwm控制技術，該系統可以廣泛應用於小功率、寬調速運行的場合。
  11. In this article, the prime task is the reasarch of extraction airplane ’ s periodic signature of modulation, the approximate entropy, the norm entropy, obtaining the sensor confidence level as well as structuring realization target identification intellectualized type fusion model and the algorithm

    本文主要工作是研究提取飛機目標的調制周期特徵，近似熵、范數熵，獲取傳感器可信度以及構造實現目標識別的智能化類型融合模型和演算法。
  12. The methodology and innovation in this paper is : ( 1 ) the problems which include modulation and demodulation of the rate biased laser gyro ' s output, algorithm of attitude updates, etc. are analysed. ( 2 ) the component level fault interactions detection of sins based on rate - bias laser gyro / dynamical tune gyroscope by using artificial neural network is investigated

    具有創新性的工作有：推導了速率偏頻激光捷聯陀螺測量信息的解調演算法；應用神經網路解決了速率偏頻激光捷聯慣導撓性捷聯慣導陀螺間的硬故障交互檢測。
  13. Based on the oled luminescent theory, we have designed the software of driving chip and driver by alternating current driving method. the driving plus ' s frequency and duty cycle can be changed by the software. we have designed a software about eight level gray - scale plus shifting modulation

    根據有機電致發光的機理，設計了交流驅動的控制晶元的軟體和驅動電路，並且對交流驅動的波形實現了驅動頻率的可調，驅動波形的占空比可調的靈活的軟體設計。
  14. The asynchronous motor is widely used for its simple construction, ruggedness, high working reliability, relatively low cost, and high environmental adaptability. it is suit for the direction of high voltage, high speed and large capacity. vector control is its ideal speed modulation method. the harmonics of three - level inverter are less than the traditional two - level inverter ’ s, and it is convenient to realize high sinusoidal voltage output. the maximum voltage strength which each electric component bears is small, and it is easy for three - level inverter to realize large capacity. the research on the asynchronous motor vector control based on the three - level inverter is one novel work

    異步電機結構簡單、堅固耐用、運行可靠、成本低、環境適應性強，容易向高壓高速和大容量方向發展，獲得了廣泛應用，矢量控制為其理想的調速方法;三電平逆變器輸出端諧波少，有利於實現輸出電壓的正弦化，且單個開關管承受的最大電壓小，適合向高壓大容量方向發展。對基於三電平逆變器的異步電機調速系統開展矢量控制研究，是一件有意義的工作。
  15. Firstly, this paper introduces the asynchronous motor model, and compares it with the dc motor ’ s. then the paper studies the principle of vector control, and proposes an improved current model of rotor flux observer. this paper also studies the three - level inverter ’ s topology, working principle, the neutral - potential unbalance mechanism and its controlling strategy. the paper especially studies the svpwm in details. the interface between the vector control and the three - level inverter is studied in details, including the generation of reference voltage vector, its judging of the sector and triangular regions, and the working mechanism after it sent into three - level inverter. when synthesizing the reference voltage vector, select the vector which only includes p and o states as the starting vector, thus eliminate the vector shift problem when sector changes. this paper fully takes advantages of the powerful functions of matlab / simulink to set up the simulation model. this construction is very explicit. the simulation results verify the inverter voltage output is correct, the rotor flux is steady, the asynchronous motor ’ s dynamic and steady state performances and speed modulation are excellent

    本文首先介紹了異步電機的數學模型，在此基礎上將異步電機的數學模型與直流電機的數學模型進行了比較;然後介紹了矢量控制的基本原理，採用了一種改進的轉子磁鏈電流型觀測模型;對三電平逆變器的電路拓撲、工作原理、中點電位不平衡的機理及控制方法進行了介紹，詳細分析了空間矢量脈寬調制策略。本文對異步電機的矢量控制與三電平逆變器之間的介面進行了詳細的研究，包括:參考電壓矢量的形成、所落扇區與具體小三角形區域的判斷、送入逆變器之後的工作機理。在參考電壓矢量的合成時，選擇只包含p 、 o狀態的空間電壓矢量作為起始矢量，解決了扇區切換時的矢量突變問題。
  16. Hfets ( modulation doped ) : modfets ? basic device, theory. deep level problem ( transconductance collapse ) ; pseudomorphic solution. telecommunications applications ? key features : gain, bandwidth, linearly, noise

    調節摻雜場效電晶體-基本元件，理論。深能階問題（電導崩塌）與假晶方案。通訊應用-主要特點：增益，頻寬，線性度，雜訊。
  17. 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。
  18. Chaotic switching modulation signals generated from different chaos sequences have been used to control smps. the effect of reducing the level of emi be compared. simulation results demonstrate : in the cpwm and cppm, chaos sequences generated from henon map is superior to the one generated from chua ' s circuit at lower multiples of switching frequency on reducing the level of emi ; in the ccfmfd, it has contrary results ; in the ccfmvd, chaos sequences generated from chua ' s circuit is superior to the one generated from henon map

    模擬結果表明： cpwm和cppm模式下， henon映射混沌序列在較低次諧波處降低emi水平的效果要好於蔡氏電路混沌序列的效果。 ccfmfd模式則有相反的結果。對ccfmvd模式，蔡氏電路混沌序列比henon映射混沌序列降低emi水平的效果明顯要好。
  19. The selective action of capsaicin on primary afferent fibers that transmit nociceptive information simulates nociceptive stimulation in vivo, therefore, the ne depression of primary afferent terminal neurotransmitter release might be significant on nociceptive modulation at spinal level

    Caps選擇性地作用於傳遞傷害性信息的初級傳入纖維，模擬了在體傷害性刺激，因此， ne對初級傳人終末遞質釋放的抑制，在脊髓水平的傷害性信息調控過程中可能具有重要意義。
  20. This paper, special research object is the qam constellation controllable adaptive modulation system, symbol rate and modulation level controllable adaptive modulation system

    本文以qam星座可調的自適應調制系統、符號率及調制電平可控的自適應調制系統為具體的研究對象。
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