spectrum of carrier 中文意思是什麼

spectrum of carrier 解釋
載波的頻譜
  • spectrum : n. （pl. -tra ）1. 【物理學】譜，光譜；波譜；能譜，質譜。2. 【無線電】射頻頻譜；無線電（信號）頻譜。3. 【心理學】（眼睛的）余像；殘像。4. 〈轉義〉范圍，幅度；（連續的）系列。
  • of : OF ＝Old French 古法語。
  • carrier : n 1 運送人，搬夫；負荷者；使役，〈美國〉信差，郵遞員；送報人；〈英國〉運輸行，運輸業者。2 傳書鴿...
  1. Technique of transmitting data via power line （ pl ） ， a new technique developed in recent years ， is used to automatize the free collecting system in public service and the management of uptown service 。 this article discussed the advantage ， disadvantage and the current state of the power line carrier communication 。 the advantage ， method and current state of using spread spectrum technique in power line communication are discussed 。 then the characteristic of low voltage power network was also compendious analyzed 。 in this paper ， after introducing the principle of ssc ， design of hardware and software of the system are been discussed 。 this system has been put into use ， the result has proved its high stability and reliability

    本文研究旨在提供一種利用低壓電力供電網路、低成本、高可靠地實現公共事業收費自動化和小區物業管理智能化的技術應用。討論了電力線載波通信的優、缺點及現狀，擴頻技術在電力線載波通信應用的優點、方式和現狀，並對低壓電力線網路的特性進行了簡單的分析。在闡述了擴頻通信的基本原理的基礎上，本文詳細地介紹了電力載波遠程抄表系統的具體實現，包括硬體模塊和管理軟體本系統已投入運行，具有較高的穩定性和可靠性。
  2. The research on carrier spectrum, modulation schemes and signal codes of plc networks has received much attention, while the mac protocol of plc networks is usually adopted from general - media computer networks

    目前國際上注重研究plc網路的載波頻率、調制方式、信號編碼等關鍵技術。而對于plc網路的mac協議，卻通常採用修改的常規計算機網路的mac協議。
  3. The reason to cause this phenomenon is due to the change of electric field in the blue oled to induce the probality of the carrier shifted and the hole - electron recombination zone changed, which was a possible alternative to achieve color display. 3 ) device with the structure of ito / npb / adn : balq3 / alq3 / mg : ag was fabricated. when the balq3 dopant concentration was about 25 mol %, a high performance devcie with luminous efficiency of 1. 0 lm / w, the peak of emission spectrum at 440 nm, the cie coordinate at ( 0. 18, 0. 15 ), and half lifetime of unencapsulated device about 950 hrs was achieved

    導致本現象的原因是由於各有機層電場強度的變化影響了空穴和電子的隧穿幾率，從而導致載流子的復合區域發生改變而發出不同顏色的光; 3 ）制備了結構為ito / npb / adn : balq3 / alq3 / mg : ag的藍光oled ，空穴阻擋材料balq3的摻入顯著影響了oled的光電性能，當balq3的摻雜濃度為25mol %時， oled的發光效率為1 . 0lm / w ，發光光譜的峰值為440nm ，色純度為（ 0 . 18 ， 0 . 15 ） ，未封裝器件的半衰期達到了950小時; 4 ）在藍光材料adn中摻雜npb 、 balq3和tbp三種材料時，不僅改善了器件的發光亮度和色純度，而且提高了器件的發光效率和壽命。
  4. Then studies a peculiar multi - carrier direct sequence spread spectrum ( mc - ds - cdma ) technology, analyzes the methods of processing multi - carrier signals and study the mathematical module of multi - carrier communication system receiver

    然後對本文所研究的這種特殊的多載波直接序列擴頻技術進行闡述，分析了多載波信號處理的方法和研究了多載波接收機的數學模型。
  5. To utilize the advantages of dsp chips, the system should be computing sources economical. according to digital signal processing theory, the poly - phase fir can help reduce the workloads of the ddc / duc. therefore, adding the complex carrier mixers, the channelization system ( a method of using a single wideband facility to transmit many relatively narrow - bandwidth signals. by subdividing the frequency spectrum used in the wideband channel ) can be formed utilizing the characters of fft

    為了使開發出的軟體可以適用於高速dsp器件開發，節省系統資源，課題首先從數字信號處理的理論進行分析，得出可以利用抽樣率轉換的數字濾波器的特點，即多相濾波實現數字上下變頻計算負擔的減小，之後進一步將多相濾波器與頻譜搬移部分結合，通過公式的推導，得出可利用快速傅立葉變換的特點實現多路信號的通道化發射和接收的處理模型。
  6. After establishing the model of intermediate frequency direct sequence spreading spectrum ( if dsss ) receiver, comparing and analyzing several conventional code acquisition methods, code and carrier two - dimension fast acquisition scheme based on two - dimension fft is proposed. finally, the situation for two targets is analyzed

    首先在建立了中頻直擴接收機的模型之後，本文對常用的偽碼捕獲方法進行了詳細地分析和比較，然後提出了本文的基於二維傅立葉變換技術的快速捕獲方法，並且分析了兩個目標時的情況。
  7. Secondly, the paper researches blind estimation of signals parameters, including the carrier frequency, signal to noise ratio and symbol rate of digital modulations. thirdly, with the combination of parameters from early studies on the decision theory, a set of robust feature parameters are extracted from signal power spectrum and the power spectrum of the second and fourth power of signal. based on these parameters, the proposed scheme is able to recognize 12 types of common used modulations, namely ask 、 2fsk 、 msk 、 4fsk 、 psk 、 qpsk 、 / 4qpsk 、 8psk 、 am 、 dsb 、 ssb 、 fm

    接著，對信號功率譜、平方譜及四次方譜進行研究，針對通信中常用的調制方式，結合前人提出的基於決策理論中的特徵參數，設計了一組對信噪比和信號調制參數不敏感的分類特徵參數，利用上述參數完成了一種基於信號頻域的識別方法，可以對ask 、 2fsk 、 msk 、 4fsk 、 psk 、 qpsk 、 / 4qpsk 、 8psk 、 am 、 dsb 、 ssb和fm這12種常用調制方式進行識別。
  8. The design of power line spread spectrum carrier communication system in fpga with digtal technology

    的數字化電力線載波擴頻系統的設計
  9. According to the principle of spread spectrum communication, the anti - interference performance of the technology is discussed and the composition of power line spread spectrum communication is described. based on the spread spectrum technique, a method which is low cost, high communications quality and low bit error for power line carrier communication using single - chip software programming is proposed

    利用擴頻通信原理，分析擴頻通信的抗干擾特性，在此基礎上，闡述了電力線載波通信系統的基本結構，提出了一種利用軟體編程實現電力線載波擴頻通信的方法。該方法不增加硬體成本，即能達到提高通信質量、降低誤碼率的目的。
  10. Since polymer light - emitting diodes ( pleds ) were invented, much efforts have been made to improve the brightness and efficiency of its electroluminescence for realizing pled commercial application. we investigated several factors influencing the brightness, efficiency and spectrum characteristics of pleds el, especially focused our attention on the processes of carrier injection, transport, recombination and annihilation factors influencing brightness efficiency of organic electroluminescence ( oel ) in doped single and double - layer pleds

    本文以提高聚合物器件的效率和亮度為目標，提出了提高及b幾種方案，研究了材料性質，器件結構，它們的穩態及瞬態特性及發光機理，特別關注了以兼具電子空穴傳輸能力的分子及摻雜聚合物作成的單雙層摻雜聚合物發光器件中的載流子注入、遷移、復合及湮滅等。
  11. This paper presented a general systematic view, application and current development of the power line carrier transmission technology, and clearly compared some existing power line carrier communication chip with each other. then the authors analyze the channel " s characters of low voltage power line, and formed an abstract carrier channel model. using this as its basis, a new kind of transmission technology is designed that adopted transmission technology combining the spread spectrum modulation with channel coding, which can solve the problems above mentioned to a certain degree, and need not pay for high cost

    文章不僅全面地介紹了電力線載波通訊技術的特點、應用及其發展狀況，還對目前的電力線載波通訊晶元進行了比較；並通過對低壓電網通道特性的分析和研究，抽象出其載波通道模型，在此基礎上，提出了將擴頻調制和通道編碼相結合的傳輸技術用於低壓電力線載波通信，這可以在很大程度上解決電力線的干擾問題，且不必付出高昂的代價。
  12. First we should analyze the user ' s needs, then should we start our work : designing the configure of database, planning the interface of the users, how to communicate via the serials, the management of the system ' s users, and so on. because the technology of spread spectrum carrier ( ssc ) communication is the kernel of the power carrier technology of communication, so we then explicate the chips we use here

    首先，本文介紹了電力載波技術及自動抄表系統在國內外的發展；接著，簡要描述了整個抄表系統的構成，本套系統由計費終端（用戶電表、水表、煤氣表等，本系統主要針對用戶電能表）數據採集器、集中控制器和中心管理軟體四部分組成，實現遠程集中自動抄錄電能表數據。
  13. But modern electronic counterwork technic could exactly estimate the carrier frequency, signal period, even the pseudo - random ( pn ) sequence itself of direct sequence spread spectrum ( dsss ). it is urgency to investigate a new dsss to achieve lower probability of detection ( lpd ) and higher anti - jamming

    然而現代電子對抗技術可以準確估計直接序列擴頻通信的載波頻率、符號周期甚至擴頻碼本身，為達到更低截獲率和更高抗干擾的通信目的，必須研究新的直擴通信技術。
  14. Ds signal is twice modulated with the rapid pseudorandom noise sequence and the carrier. so it appears cyclostationary. in the field of spectral correlation, ds signals appears its characteristic as fallows : for the amplitude of spectral correlation, the information of carrier frequency and pn code rate are contained on the spectrum frequency equal to zero sheet, and also the pn code rate is contained on the sheet of spectrum frequency equal to carrier frequency ; for the phase of spectral correlation, the information of carrier initial phase is contained on the sheet of cyclic frequency equal to double carrier frequency

    Ds信號是經過高速偽隨機序列和正弦載波二次調制的寬帶信號，因此具有周期平穩特性，它在譜相關域表現為:幅頻特性在譜頻率等於零截面切片上包含了載頻和偽碼速率信息特徵，在譜頻率等於載頻截面切片上包含了偽碼速率信息特徵;相頻特性在循環頻率等於兩倍載頻截面切片上包含了載波初相信息特徵。
  15. According to the carrier wave leakage and mirror wave interference in the signal generation, this paper analyzes the source of waveform distortion and its influence to signal spectrum and pulse compression result

    針對生成信號中存在的載漏和鏡像等失真，本文對波形失真來源及其對信號頻譜及脈壓結果的影響進行了全面分析與模擬。
  16. Finally, the paper studies the dsss signal detection and its parameter estimation in non - cooperative communication using the strong self - correlation of spread spectrum sequence. these parameters are the carrier frequency, baud period, chip period and chip sequence

    最後，利用擴頻序列的強自相關特性，研究了直接序列擴頻信號在非協作通信中的檢測和參數估計問題，研究的參數包括:載頻、符號周期、碼片周期和擴頻碼序列。
  17. System scheme of speech coding plus spread spectrum communication was presented based on a full analysis of noise characteristic, attenuation characteristic and impedance characteristic of low - voltage power line. spread spectrum carrier ( abbreviated as ssc ) technology is adopted to overcome problems existing in signal transmission over power line. high quality, low rate mbe compression algorithm was used to complete speech encoding and decoding

    在對低壓電力線路的噪聲特性、衰減特性和阻抗特性三個方面充分分析的基礎上，本文提出一種語音編碼+擴頻傳輸的系統總體方案，採用擴頻載波（ spreadspectrumcarrier ，縮寫為ssc ）技術克服電力線傳輸信號存在的問題，採用語音合成質量高並具有較低碼率的mbe壓縮演算法完成語音信號的編解碼。
  18. On the basis of the former research works, we present the detecting method as follows : for the narrow band characteristic of the track signal we use under - sampling instead of nyquist sampling to reduce the sampling rate. as to the carrier frequency, the spectrum of the 18 - information frequency - shift track signal has two peaks, then the carrier frequency is the average of the two peak frequency, to um - 71 jointless track signal, it has only one peak, then the carrier frequency is the peak frequency

    針對移頻軌道信號的窄帶特性提出了使用欠采樣技術代替奈奎斯特采樣的方法，以降低信號的采樣頻率;國產18信息移頻軌道信號頻譜具有雙峰，雙峰頻率平均值就是信號的載頻頻率，而um - 71無絕緣軌道信號頻譜單峰，峰值頻率即為信號的載頻頻率。
  19. The square detection can picks up the carrier frequencies, which is simple and has great performance. but this method can ’ t recognize the signal as spread spectrum signal. the spectral correlation detection method can estimates the chip rate of signal ’ s pn sequence

    然後，針對異步的cdma信號，採用延遲相乘的方法檢測用戶數目，同時估計出各用戶信號的幅值和相位;該方法的缺點是各用戶信號必須有一定的相差，同時用戶數不能太多。
  20. The method was correlate search and fft carrier detection, which could solve the problem of the capture of the spread spectrum code under the condition of low snr and big frequency offset. we also put forward a method, shift receiving window and correlate with local sequence, which not only could solve the problem of symbol synchronization but also could acquire the statistics of the multipath. then we utilized the results of the channel estimation and the technology of rake receiver to decode the received spread spectrum sequence and acquire rude information

    方案中提出了：相關搜索、 fft檢測信號載波的方法，解決了低信噪比、大頻差條件下擴頻碼的同步捕獲難題；滑動相關完成位同步的方法，解決了低信噪比下的同步問題；在時域利用相關進行通道估計，然後利用rake接收技術完成相關解擴的方法，一定程度上解決了多徑衰落影響解擴性能的問題。
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