modulation band 中文意思是什麼

modulation band 解釋
調制頻帶
  • 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...
  • band : n 1 帶，繩；帶形物；箍；箍條；嵌條；鑲邊；鋸條； 〈pl 〉 （法官等的）寬領帶。2 束縛，羈絆；義務；...
  1. Amssb amplitude modulation, single side - band

    單邊帶調幅
  2. Amdsb amplitude modulation double side band

    雙邊帶調幅
  3. The research of base band ijf coding and modulation technologies

    編碼調制技術的研究
  4. After elaborating the principle of an 802. lib key modulation scheme - complementary code keying ( cck ), this paper proposes and realizes a hardware circuit solution of 802. 11b pcmcia wlan interface card, which can reliably offer a maximal 11mbps data rate and freely switch within 14 working channels in 2. 4ghz frequency band

    接著在詳細闡述了802 . 11b協議核心調制技術?互補碼鍵控（ cck ）的原理的基礎上，本文提出並實現了一種峰值傳輸速率為11mbps的802 . 11bpcmcia高速無線網卡的硬體電路設計方案，在2 . 4ghz頻段該網卡可在14個工作通道上自動切換，實現高速突發數據的可靠傳輸。
  5. This paper starts the research of the liquid floated pendulous accelerometer testing system according to the engineering. at first, this paper gives the brief introduction of the history and present status of accelerometer and its testing technology, the working principium and math model of the liquid floated pendu - lous accelerometer, and then, decides the binary width pulse force retrim loop as the design proposal of testing system, researches the transfer function of every part in the system emphasizly, analyses the stability of the whole accelerometer testing system from the angle of control theoretics by the open loop transfer function of system, and designed the correcting net, analyses the basal problems such as resolution, sampling restraint, precision and so on, designs the hardware testing circuits such as preamplification, band - pass filter, alternating amplifier, phase sensitive demodulatorn, pulse - width modulation, frequency scale circuit, moment current generator. finally, using the graphics program language labv - iew which is designed for testing field especially by ni accomplishes the solfware design of testing system, realized the testing functions

    首先對加速度計及其測試技術的發展歷史和現狀，液浮擺式加速度計的工作原理和數學模型等作了簡要的介紹，然後確定了以二元調寬脈沖再平衡測試迴路為設計方案，並從控制理論的角度進行了分析，著重研究了系統中各部分的傳遞函數，利用系統開環傳遞函數分析了系統的穩定性，同時設計了系統的校正網路;分析了二元調寬脈沖再平衡測試迴路的解析度、采樣約束以及測試精度等基本問題，並按照系統分析的結果設計了包括前置放大、帶通濾波、交流放大、相敏解調、脈寬調制、頻標電路以及力矩電流發生器等測試系統各部分硬體電路，驗證了電路的正確性，最後按照測試系統的要求，採用了美國ni公司專為測試領域所開發的虛擬儀器工具? ? labview作為測試軟體開發工具，利用該圖形化編程語言完成了測試系統軟體部分的設計，實現了測試功能。
  6. For phonetic signal modulation, if the pass band range of the band pass filter ( bpf ) is 300hz - 3400hz, the anti - noise properties of laser are approximately independent of bias current and parameters of the cavity ; when the pass band range of bpf increases to a certain degree, modulating bias current and parameters of the cavity can improve the anti - noise properties of laser

    對語音調制情況，如帶通濾波器的通帶范圍取為300hz - 3400hz ，則激光器的抗噪聲性能基本不依賴于偏置電流和腔內參數；當帶通濾波器的通帶范圍增大到一定程度，調整偏置電流和腔內參數可以實現半導體激光器的高抗噪聲性能。
  7. The carrier wave is modulated directly by the baseband signal at several frequency point in l band and s band. firstly, this paper clarifies the theory of i / q modulation, elaborates evm and acpl, and analyzes the effect of amplitude and phase unbalance and dc offset on evm. secondly we review the basic principle of phase locked loop and it ’ s composing parts, including the basic conception and design method of pll frequency synthesizer, especially introduce the charge pump pll frequency synthesizer in detail

    首先，在闡述i / q正交調制基本原理的基礎上，通過對誤差矢量和鄰近通道功率泄漏的詳細分析，定性、定量地討論了各種非理想電路因素（如相位不平衡、幅度不平衡、直流偏差等）對調制器性能的影響;其次，介紹了鎖相環的工作原理和基本組成部分，包括鎖相環的設計和環路濾波器的設計，特別詳述了電荷泵鎖相頻率源;第三，介紹了採用直接調制技術模擬衛星信號的射頻前端的設計;最後，對整個直接射頻調制系統進行測試，結果基本上達到了課題要求。
  8. Modulation on widening photonic forbidden band of one - dimensional photonic crystal by optical thickness

    光學厚度對一維光子晶體禁帶寬度的調制
  9. This paper mainly focuses on the noise limiting by means of the direct sequence spread spectrum ( dsss ) and the analysis of the transmission performance of the plc and some digital modulation technology. the contents of the paper is as follows : 1 ) the technical feasibility is proved after simulating noise limiting principle of dsss by means of systemview, the simulation software ; 2 ) a kind of band pass filter ( bpf ) is realized according to the requirement of filter and the principle of butterworth approximation, which satisfies the index of performance of dsss. 3 ) the low voltage plc system includes the sc1128, the specific modulation / demodulation ic, the bpf filter and other circuit components, furthermore, the control function of system is realized by means of the personal computer and the microcontroller

    本課題在對低壓電力線的傳輸特性和數字調制技術進行分析的基礎上，將通信理論中的直接序列擴頻技術（ dsss ）用於解決低壓電力線通信的干擾問題，主要研究內容如下： （ 1 ）用通信模擬軟體systemview對dsss技術的通信和抗干擾原理進行模擬分析，分別對時域和頻域下採用dsss技術前後接收信號的頻譜進行分析，驗證dsss技術在本系統中的可行性； （ 2 ）由dsss技術對濾波系統的要求，根據濾波理論分析了巴特沃思型濾波器的逼近原理並設計了合適的濾波電路； （ 3 ）用調制解調晶元sc1128和自行設計的濾波器加之輔助外圍電路，構造出低壓電力線載波通信系統，並採用atmel公司的單片機設計了接收和發射電路的微控制器； （ 4 ）分別對採取抗干擾措施前後輸入和輸出信號進行對比實驗，並對結果進行分析，驗證了dsss技術對干擾信號的抑制作用。
  10. In order to achieve high data rates on the severely band - limited underwater acoustic ( uwa ) channels, bandwidth - efficient modulation techniques must be employed, together with some sophisticated signal processing algorithms, such as adaptive equalization technique for the intersymbol interference caused by channel multipath propagation

    在帶寬嚴重受限的水聲通道中實現高數據率通信，必須使用高帶寬利用率調制技術，並結合自適應均衡等技術以有效地克服通道多途傳播產生的符號間干擾。
  11. 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。
  12. 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。
  13. By theory and practice simulation, the several types of constant envelope modulation techniques are analyzed and compared, including theirs modulation principle, phase path, the modulated wave envelope, power spectrums, error bit rate and the influence of its power spectrums of the band - limited and non - linear, etc. especially we have researched the ijf - oqpsk modulation technique, and the performance of its inter - symbol interference and time jitter free, and its strongly resisting of spectral spreading

    結合理論和實驗模擬結果，分析討論了衛星通信中的各種恆包絡調制技術，對它們的調制原理，相位路徑，已調波包絡，功率譜密度，誤碼性能，以及帶限非線性通道對其功率譜的影響等方面都作了研究和比較。特別研究了ijf ? oqpsk在消除碼間干擾和定時抖動方面的性能及其優良的旁瓣特性和抑制頻譜擴展特性。
  14. Digital tv qpsk modulation in the treatment of the data flow of energy to deal with the proliferation of randomization, rs codeconvolution interleave contraction coding, modulation before forming the base - band processing to ensure that the data transmission performance

    Qpsk數字電視調制器在對數據流的處理上採用能量擴散的隨機化處理rs編碼卷積交織收縮卷積編碼調制前的基帶成形處理等，保證了數據的傳輸性能。
  15. In this paper, direct modulation technology working at microwave band is researched

    本文研究的是微波波段的直接調制技術。
  16. In this thesis, complex analytical band - pass filtering based method is proposed to reduce the modulation complexity ; polyphase decomposition is used to reduce the filtering complexity ; uniform dft filter banks based method exploits the center frequency distribution characteristic of filter banks to reduces the modulation and spectral resort processes

    而基於均勻dft濾波器組的演算法充分利用了濾波器組的中心頻率的分佈特點，省略了復頻移環節和整序環節，同時利用多相分解的方法改善了濾波環節，兼有各種方法的優點而大大的提高了演算法的實時性。
  17. Of course, the next big step for chinese space astronomy would be to deploy a satellite dedicated only for astronomical research. there are currently a few projects in the planning stage, including a hard x - ray all - sky survey satellite the hard x - ray modulation telescope mission, and a " microsatellite " weight less than 100 kg mission to study long - term variability of stars and galaxies space - based multi - band variable objects monitor

    當然，下一步首先應是發射專門用作天文研究的衛星，目前有幾個計劃正處于策劃階段，包括建造一枚作硬x射線巡天觀測的衛星硬x射線調制望遠鏡， hxmt和一枚微型衛星重量不逾100公斤，來研究恆星和星系的長期變化空間變源監視器， svom 。
  18. Aiming to achieve mini - type designment, and transmitting farther on the setting frequency band, direct frequency modulation is chosen after comparing the advantage of amplitude modulation with that of frequency modulation

    為了實現微小型化的設計，並且使系統在設定的傳輸頻段上傳輸距離較遠，在比較調幅與調頻的優缺點后，我們選擇了直接調頻的調制方式。
  19. For implement of wide band modulation, multi - carries and elimination of adjacent channel interference to satisfy ber requirement in wcdma system, which is most popular in 3g technology, the linearity requirement of the base station power amplifier becomes tighter

    以wcdma為代表的第三代移動通信技術，為實現寬帶調制、多載波應用，同時減小鄰通道干擾以滿足通信系統的誤碼率要求，對基站發射機功放的線性指標要求苛刻。
  20. 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。
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