時頻調制 的英文怎麼說

中文拼音 [shíbīndiàozhì]
時頻調制 英文
time frequency modulation
  • 時 : shí］Ⅰ名1 （比較長的一段時間）time; times; days:當時at that time; in those days; 古時 ancient tim...
  • 頻 : Ⅰ形容詞（次數多） frequent Ⅱ副詞（屢次） frequently; repeatedly Ⅲ名詞1 [物理學] （物體每秒鐘振動...
  • 調 : Ⅰ動詞1 （配合得均勻合適） harmonize; suit well; fit in perfectly 2 （使配合得均勻合適） mix; adju...
  • 制 : Ⅰ動詞1 （製造） make; manufacture 2 （擬訂; 規定） draw up; establish 3 （用強力約束; 限定; 管束...
  1. And then facing the problem of the channel estimation of the adaptive modulation system, we conclude out the channel estimation algorithms on maximum likelihood ( ml ) estimation and maximum a posteriori ( map ) estimation under the condition of flat fading channel and selective fading channel in detail. to meet flat fading channel, we simulate the relationship of the ratio between the error covariance in map estimation and ml estimation and pilot symbol message length. the conclusion can be drawn from these results

    接著，對自適應調制系統中的通道估計問題難點，詳細推導了平衰落通道條件下和選擇性衰落通道條件下最大似然（ ml ）估計和最大后驗概率（ map ）估計演算法，針對平衰落通道，我們模擬了map估計和ml估計的方差與導頻符號長度的關系，模擬結果表明，錯誤方差受多譜勒頻率的變化影響最大，並且對實際的自適應調制系統，導頻符號長度的取值超過20個符號長度時， map通道估計明顯優于ml通道估計。
  2. In this thesis, firstly, we put forward a new algorithm of the synchronization of carrier reference phase, that is to use the curve synthesizing with the general digital carrier phase looper to have an estimation on carrier frequency within 10 ms so as to meet the need of meteor burst communication. we have done some simulations to get the performance of carrier frequency estimation using two modulation modes ( 16qam and 4 - qpsk ), and had some test on the carrier phase looper in conditions when using different baud rate transmission and when the baud tuning have windage

    我們對兩種正交調制方式（ 16qam和4 - qpsk ）進行了模擬工作並給出了模擬結果，同時討論了碼元同步定時誤差對鎖相環路工作的影響並根據流星通信中使用變速率傳輸時鎖相環路的載波同步性能進行了測試；然後在基於軟體無線電思想的數字處理平臺（該數字處理平臺實現了中頻數字化）上用dsp軟體完成了載波的相位跟蹤。
  3. The second, at the high frequency primary coil, when switch turn on with control signal ( the spwm pulse is modulated ), in the positive or negative semi - period of low frequency modulation signal, transformer coil with same direction voltage. the magnetic flux of transformer core will increase step by step. at the end, it leads to magnetic flux saturation

    二、在高頻變壓器原邊，當開關管接收控制信號脈沖列（經調制的spwm波列）導通時，在低頻調制信號的正半周或負半周內，施加在變壓器繞組上的是同一方向的電壓，變壓器磁芯中的磁通可能將級進地逐漸增加，導致磁芯飽和，造成磁偏或單向磁化，導致低頻電信號放大失真或由於很大的磁化電流而無法正常工作。
  4. When the cur - cuit resets, the chip remains accepting state, works in burst mode, and adopts dpsk modulation mode. it proceeds quadrature - sampled intermediate frequency signal after the ad9057 has converted, then down - converses, despreads and demodulates. the demodulated baseband signal will be sended into scm to dispose through interrupt

    上電復位后，晶元處于接收狀態，工作在突發模式下，採用dpsk調制方式，將ad9057轉換完的中頻信號進行復正交取樣後下變頻、解擴、解調，通過中斷將解調完的基帶信號送入單片機處理；處于發送狀態時，可將數據擴頻、調制，經ad9768送出。
  5. 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。
  6. Secondly, introduce discrete multi - tone modulation principle in detail, have a systemic and comprehensive analysis and explanation on minimum mean square error ( mmse ) channel shorten time domain equalizer design methods which are based on all kinds of cost functions, analyze their advantage and disadvantage. research on time domain equalizer structure, compare all the time domain equalization algorithm with simulation which afford a valuable reference for the choice of equalization algorithm and equalizer structure when design time domain equalizer

    詳細介紹離散多音頻調制原理，對mmse通道縮短法和基於其他代價函數的時域均衡器設計方法的進行了系統全面的分析和闡述，分析了各自的優缺點；對時域均衡器結構進行研究；模擬比較了各種時域均衡方法，為進行時域均衡器設計時均衡演算法、均衡器結構的選擇提供了有價值的參考。
  7. It realizes the functions of storing and transferring the information of fire alarm, displaying time, scanning keyboards, the safe maintenance of system and so on. the part of wireless communication is controlled by at89c2051 mcu, mainly realizing transmitting and receiving data between controller and other detectors. the external signals received by a wireless module are transmitted to mcu through shaping circuit, and the signals of mcu are transmitted by a wireless module through tone modulation circuit

    人機交互部分以單片機c8051f020為核心，為用戶提供一個良好的操作環境，實現了火災報警信息的存儲及調用、時間的顯示、鍵盤的掃描、系統的安全維護等功能;無線通信部分由單片機at89c2051來控制，主要實現控制器與其它探測裝置之間信號的無線發射和接收，無線通訊模塊接收到的外部信號經過整形電路送入單片機，單片機發出的信號經過音頻調制再由無線通訊模塊發送出去，這樣實現了數據的無線傳輸;本文還從節能的角度出發，兼顧性能的可靠性，提出了一種合理的無線火災報警的信息傳輸模式。
  8. This paper is devoted to a detailed investigation of non - steady interaction between the moving body and plasma in compression region, whose dominating equations are obtained and whose phenomena are simulated

    文獻[ 12 ]中採用雙流體、雙時標近似，得到了壓縮區內高頻調制場對帶電粒子非穩態作用的控制方程。
  9. 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。
  10. 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。
  11. Secondly, we apply tk operator to the cross - correlation of received signal code and pn code to separate the multi - paths. it comes to a conclusion that tk operator can separate the multi - paths within less than the chip period accurately of spread - spectrum system with space - modulation by simulation. at last, we apply this algorithm to the practical signal collected by gps tap, and from the result we can drop a conclusion the tk algorithm is practical

    本文首先闡述了時空調制擴頻信號原理以及在多徑干擾下時空調制接收機的性能和teager - kaiser接收機的原理;接著對時空調制擴頻系統的解調信號與偽碼的互相關函數採用tk接收機進行多徑分離，模擬結果表明， tk接收機對時延在一個碼片內的時空調制擴頻通信多徑信號有很好的分離效果;最後用數據採集器對一個gps信號進行接收和多徑的估計，驗證了該演算法在實際的運用中對多徑的擴頻信號有很好的分離效果。
  12. The test results demonstrated the feasible of the scheme. the technique researched in this paper will largely simplify the equipment of modulation and demodulation, and may find its application in millimeter wave in high - speed data communication link

    與中頻調制方案和一般直接射頻調制方案相比，本文所採用的技術大大簡化了調制/解調設備，同時保持了優良的性能，對毫米波高速數據通信鏈路應用具有較大的優越性和廣闊的前景。
  13. It consists of two parts : channel modulator ' s controlling system and the receiver ' s controlling system, including the interface designing of the demultiplexer, the controlling of the channel demultiplexer, if modulator, tuner, the setting and transmitting of the system parameters, and the real - time monitoring of the whole system, etc. based on the descriptions of the scheme of bdb - t and the principles of controlling circuits, this paper presents the hardware and software designing methods of the controlling circuits, and realizes a powerful, multifunctional and reliable controlling system which can automatically record the operational states of the system and communicate with other personal computers through a rs - 232 serial interface

    控制系統是實現整個傳輸系統的關鍵部分，它分為通道調制器控制系統和接收機控制系統兩大部分，其中包括了通道解復用器用戶介面設計、對通道解復用器的控制、系統傳輸參數的設置與傳送、中頻調制器的配置、數字調諧器的配置，以及對整個系統的實時監控。本文在闡述了bdb - t方案及其各部分電路的控制原理的基礎上，詳細描述了控制系統的硬體電路設計和軟體實現方法，實現了一套功能完善、性能穩定且具有自動記憶功能的控制系統，同時該系統通過rs - 232串列介面可以實現與計算機的串口通信。
  14. The main results and creative points in the dissertation were as follows : a ) by means of studying on the fiber - optic hydrophones ’ tdm array based on phase generated carrier ( pgc ) demodulation with laser frequency modulation, the mathematic models were set up, used for theoretical analyses of noncoherent crosstalks in the system using low coherent laser and coherent crosstalks in the system using high coherent laser. the formulas calculating crosstalks were given, and the method measuring crosstalks was shown definitely

    本論文的主要研究結果和創新在於: 1 、通過對基於光頻調制pgc （相位生成載波）解調光纖水聽器時分復用系統的研究，針對低相干光源的串擾強度迭加和高相干光源串擾的相干迭加，建立了理論分析的數學模型，得出了計算串擾的公式，明確了測試系統串擾的方法。
  15. A new spread - spectrum system with four phases space - time modulation for direction - finding and ranging

    一種新型同時測向測距四相時空調制擴頻系統
  16. This dissertation focuses on the hardware design of software radio with the aim to solve the problem of producing and receiving space - time modulation signals

    本文就基於pci總線的軟體無線電硬體實現開展了初步的研究，目的是用來解決中頻時空調制信號的產生與接收問題。
  17. And what we do in this paper is to put forward an effective algorithm to estimate the sub - chip multi - path component of spread - spectrum positioning system with space - modulation and put it into practice

    為此，本文針對時空調制擴頻定位系統給出一種有效的碼片內多徑估計的演算法，並用gps擴頻系統的多徑信號進行多徑估計驗證。
  18. The radio frequency receiver supports interface for instrument and base station and air interface for mobile station, and it takes the task of magnifying low noise and down - convert and digital baseband processor filtering and magnifying intermediate frequency to reverse link signal. the digital baseband processor samples the received signal after down - convert radio frequency signal to intermediate frequency signal and processes other processing and supports interfaces to computer, next sends data to computer. the gps receiver supports interface for instrument and gps system, and receives gps system signal, next it demodulates the correlative information and sends out benchmark clock signal we need

    射頻接收部分主要為儀器和基站、移動臺提供空中介面，其主要任務是在反向鏈路上對接收到的射頻調制信號進行低噪聲放大、射頻下變頻變換、中頻濾波放大等;數字基帶部分為對接收信號變頻為中頻后進行a / d采樣，以及其他的rsp處理並和計算機提供介面，將數據送至計算機進行后臺處理、顯示等; gps接收機部分為儀器和gps系統提供介面，接收gps系統信號並解調相關信息，輸出所需的電文及時鐘基準信息等。
  19. This chapter is a base of next chapter. mathematics theory and pseudo stochastic code theory for spread spectrum modulation sequence are introduced, and simulink experiment and analysis about correlation performance of the most common use spectrum modulation sequence are processed, these experiment contact to performance parameters of the spread spectrum sequence. the correlation performance and address quantity are compared between m sequence and gold sequence

    本章是第五章的理論基礎，介紹了擴頻調制序列的數理基礎和偽隨機碼理論，同時聯系調制序列的性能指標對最常用的兩種擴頻調制序列的相關性能進行了模擬研究和分析討論，比較了m序列和gold序列互相關特性和地址數。
  20. And the spreading modulation, radiation signal modulation and choosing of waveform parameters are also discussed, which is the base of the receiver designing

    同時對擴頻調制方式、射頻信號調制方式以及波形參量的選擇進行了重點的論述，並對擴頻通信系統的相關指標進行了計算。
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