key modulation 中文意思是什麼

key modulation 解釋
鍵控調制。

  • key : n 1 鑰匙。2 要害，關口，要沖。3 關鍵，線索，秘訣；解法。4 （外國書的）直譯本，圖例，題解，圖解，...
  • 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. 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。
  2. 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。
  3. 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。
  4. However, the modulation - demodulation of ultraviolet and voice transmission are the key technologies

    然而，紫外光通信的調制解調技術以及語音傳輸是整個系統的關鍵難點。
  5. As a result, some key technologies of sdr such as modulation, demodulation, ddc and dug have been hot topics. in this paper, some key technologies of sdr are researched deeply

    於是，軟體無線電中的一些關鍵技術，例如：調制解調技術，數字上變頻，數字下變頻等成為該領域的研究熱點。
  6. One of the key problems of designing the control valve of modulation rotary steering drilling tool is the design of high pressure hole of upside valve

    摘要設計調制式旋轉導向鉆井工具控制閥的關鍵問題之一是上盤閥高壓孔的設計。
  7. The main part and key technique of the cpa system is study : the generation of the femtosecond laser pulse is study, the modulation and maintenance of the ti : s laser is learned ; the types of the measurement for ultrashort laser pulse is generalized and the interferometric autocorrelation is expatiated ; the varieties of the stretchers is sum up and aberration - free stretcher is calculated and optimized to improve the stretching ratio ; the pulse selection is analyzed and a single pulse can be selected successful from the pulse train at a repetition rate of 82mhz ; the kinds of the amplifier in cpa system is gathered up, the eight - pass pre - amplifier and a good many effects in it is investigated. finally, the second, third and fourth - order dispersions in cpa system is analyzed systemicly, and the according means for dispersion compensation is worked out

    對cpa系統的主要環節及關鍵技術進行了研究：掌握了鈦寶石激光器的調節和維護技術，較深入地研究了飛秒激光脈沖產生的機理，其中對群速色散、自相位調制、自鎖模等問題進行了詳盡的分析；總結了超短激光脈沖的測量技術，重點研究了干涉自相關測量法；在總結展寬器類型的基礎上，對無象差展寬器進行了理論計算、優化設計，提高了展寬倍數；深入論述了脈沖列的選單問題，熟練掌握了脈沖選單技術。
  8. 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。
  9. 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。
  10. The purpose of this paper is to resolve some key technologies of the amplitude - modulation inductive displacement transducer signal processing circuit with nanometer resolution, such as the design of high stability signal generating circuit ; the technology of high precision digital phase - sensitive detection circuit ; the technology of digital filter and linearization, etc

    本文主要研究調幅式電感位移傳感器精密測量系統中涉及的高精度載波信號發生技術、高精度數字相敏檢波技術、數字濾波及線性擬和等關鍵技術，目的是進一步改善調幅式電感位移傳感器精密測量系統的測量精度，適應納米級測量的要求。
  11. The modulation recognition of communication signals is one of the key techniques of communication reconnaissance, and it is also an important task in the field of electronic warfare

    通信信號調制方式的識別是通信偵察的關鍵技術之一，是目前電子戰的重要研究課題。
  12. Secondly, comparing with the algorithm that was given by english scholars a. k. nandi and e. e. azzouz in 1995, this dissertation presents a modified automatic recognition algorithm of six kind of digital modulation types such as 2ask, 4ask, 2psk, 4psk, 2fsk and 4fsk, which only uses four key features, and has a very great exaltation in the rate of correct recognition and the performance of signal to noise, we puts forward the constitution of the best threshold which is applicable to the signal that changes within the scope of the signal to noise rate ( snr ) from 5db to 30db, and the overall success rate is not lower than 92 % when snr is over 7db

    其次，針對1995年英國學者a . k . nandi和e . e . azzouz提出的針對2ask 、 4ask 、 2psk 、 4psk 、 2fsk和4fsk這六種常用的數字調制信號識別的演算法，提出了一種數字信號調制方式識別演算法（ dmra ）的改進演算法。該演算法僅利用四個特徵參數，就可以識別這六種調制方式，而且在調制識別率和信噪比性能上都有了很大的提高，能夠在信噪比不低於7db時，對實際信號的識別正確率高於92 % 。並且提出了最佳門限的設置方法，設置的門限適用於信噪比在5db ~ 30db范圍內變化的信號。
  13. In this dissertation, ofdm which has been the hottest spot in communication field recently will be considered as my direction. the dissertation will study some key techniques in mc - cdma system, such as modulation technique, peak - average power ratio, detection technique and synchronization problem of the whole system. what ' s more, the results of calculation and simulation will be given

    本文以目前通信領域的熱點： ofdm （正交頻分復用）為研究方向，對于多載波cdma系統中的若干關鍵技術，即多載波cdma系統中的調制技術、峰平比性能、接收端檢測技術以及整個系統同步問題進行了研究，並給出相應的計算機模擬結果。
  14. The general requirement of communication system and the application potential in secure communication are expatiated. the chaotic secure communication methods home and abroad are also summarized, including chaos spread spectrum communication, chaos key - shifting, chaos parameter modulation, chaos masking, chaos cdma. the exiting problems and development direction are also pointed out respectively

    介紹了混沌學的發展過程和意義，闡述了通信系統的一般要求和混沌在保密通信中的應用潛力，綜述了國內外現有的混沌保密通信方法，其中包括：混沌擴頻通信，混沌鍵控，混沌參數調制，混沌掩蓋，混沌數字碼分多址等五大類，指出了各自存在的問題和發展方向。
  15. Moreover, a novel method is also proposed to using pdp driving ic to perform the traditional pwm modulation. the shared platform is also discussed. besides the circuit design and program, in the paper, according to the typical equivalent pixel unit circuit, analyze the key parameter of the circuit by the support of theory formula deduction, analysis and simulation. it ’ s favorable to improve the high - frequence property of fed sample and enhance the display quality

    實際上，文中還提出了採用pdp驅動晶元進行pwm調制的控制方法和相應驅動波形設計，並就與子行灰度調制方法共享有關硬體和軟體平臺來驅動fed顯示屏進行了有益的探討。除了電路製作和控制編程外，本文從fed顯示屏典型像元的等效電路入手，採用理論公式推導、分析和模擬結合，指出了驅動電路設計中的關鍵參數選擇準則。這有利於改善fed整機的高頻特性，提高fed的顯示質量。
  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. Secondly, the ipos is introduced on the whole, including network architecture, protocol reference mode, and two key technologies : the hybrid arq error control and adaptive coding modulation. meanwhile, the qos standard specifically used in the dissertation is presented

    之後從總體上對ipos協議進行介紹，分析了其網路結構，協議模型，混合arq控制機制、自適應編碼調制這兩項ipos協議的主要技術組成等內容，並提出了本課題採用的qos指標。
  18. Measurement accuracy of phase - shift laser range finders is up to millimeter level in large range through multi - frequency modulation and high precision phase difference measurement. however, laser range finders existing is not suitable for large range high speed tracing measurement for their complex multi - frequency modulation circuit and conflict between precision and speed in phase - shift measurement. in order to improve the large range measurement speed and accuracy, key technologies on multi - frequency modulation and high precision phase - shift measurement are deeply researched in this paper

    相位法激光測距採用多頻調制和高精度的相差測量技術可以在大范圍內實現毫米甚至更高精度的測量，但現有的測量裝置由於存在多頻調制電路復雜和沒有很好的解決相差測量的高精度和快速測量之間的矛盾問題，使得相位法激光測距很難應用於大范圍目標快速的跟蹤測量。
  19. First, this paper analyses a bicm model and the bicm _ id model based on combination of convolutional code and 8psk modulation, and introduces the principle and key technique

    本文分析了一個基於卷積碼和8psk調制相結合的bicm模型和相應的bicm _ id模型，介紹了它們的原理和其中的關鍵技術。
  20. In the code division multiple access ( cdma ) system, the multiple access interference ( mai ) mitigation capability as well as system capacity are determined, to a great extent, by the correlation properties of spreading sequences ; while adaptive modulation and coding ( amc ) with high spectral efficiency is the key technique to obtain high speed and low symbol error rate ( ser ) performance in mobile data transmission

    在碼分多址（ cdma ）系統中，擴頻序列的特性在很大程度上決定了抗多址干擾（ mai ）能力和系統容量，而高頻譜效率的自適應調制編碼（ amc ）技術則是獲得高速率和低誤碼率（ ser ）移動數據傳輸性能的關鍵因素。
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