特定頻率干擾 的英文怎麼說
中文拼音 [tèdìngbīnlǜgānrǎo]
特定頻率干擾
英文
spot jamming- 特 : Ⅰ形容詞(特殊; 超出一般) particular; special; exceptional; unusual Ⅱ副詞1 (特別) especially; v...
- 定 : Ⅰ形容詞1 (平靜; 穩定) calm; stable 2 (已經確定的; 不改變的) fixed; settled; established Ⅱ動詞...
- 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...
- 率 : 率名詞(比值) rate; ratio; proportion
- 干 : 干Ⅰ名詞1 (事物的主體或 重要部分) trunk; main part 2 (幹部的簡稱) short for cadre Ⅱ動詞1 (做...
- 擾 : Ⅰ動詞1 (擾亂; 攪擾) harass; trouble 2 (客套話 因受人款待而表示客氣) trespass on sb s hospital...
- 特定 : 1. (特別指定的) specially appointed; specially designated 2. (某一個) given; specified; specific
- 頻率 : frequency; rate
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In current practice, array parameters are usually calculated according to the strength and types of interference wave, frequency characteristics, and azimuth, whereas the effect of array center is often ignored, and simply view the graphic center as array center
指出現在施工設計中,組合參數的確定主要圍繞干擾波、頻率特性和方位角等方面進行論證,忽視了其組合中心的確定。The future wireless mobile communication systems are expected to provide ubiquitous, high - quality, and high - rate mobile multimedia transmission. however, hostile multipath fading radio conditions give rise to serious inter - symbol interference ( isi ) ; even worse, wireless channel are often time varying, which makes the system more vulnerable and more difficult to track the channel state. orthogonal frequency dvision multiplexing ( ofdm ), which is inherently resistant against isi, has invoked a popular research interest in recent years, and has been a promising candidate technology of the physical layer for future weideband high - date - rate wireless communications. notwithstanding, ofdm is much more vulnerable to errors of both time and frequency synchronization and to that of channel estimation, and how to obtain correct timing and channel estimation efficiently is highly critical to ofdm systems. the dissertation will focus on both of the aspects of ofdm systems mentioned above
但是無線環境的多徑特性造成通信系統中嚴重的符號間干擾,同時無線通道的時變性使得通道特性跟蹤復雜。而正交頻分復用技術( orthogonalfrequencydivisionmultiplexing , ofdm )正是一種解決符號間干擾的有效傳輸手段,因此ofdm技術作為未來寬帶高速率無線通信的物理層候選技術在當前引起了一股研究熱潮。但ofdm系統對定時同步誤差和通道估計誤差非常敏感,如何在ofdm系統中準確快速地實現符號同步和通道估計是至關重要的,本論文將重點針對這兩個問題進行討論。As a new communication mode, the spread spectrum communications are widely used in military communication, distance finding and precise position, because of its well multiaddress access, lowly capture probability, the excellent performance of anti - interference and secrecy
擴頻通信作為新型的通信方式,以其優良的多址接入、低截獲概率特性、抗干擾特性和強保密性被廣泛應用於軍事通信、測距與精確定位。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。Transmition velocity relys on the style of encode and modulation essentially during modern data transmition for the quality of using line bandwidth and the immunity of code ties on them tightly. but it is important that the velocity of data transmition reaches its limitation in fact for the interface of environment and cross - talk. so for the improvement of transmition velocity, we must analyze the characteristics of noise signal and the model of line deeply and then take some useful measures to better the immunity of modulation wave
在現代通信的數據傳輸過程中,傳輸速率本質上是由傳輸的編碼方式和調制方式決定的,因為編碼方式和調制方式直接決定了線路頻帶利用率和碼元抗干擾能力的好壞,因而直接決定了傳輸速率;但是在實際應用過程中,數據傳輸速率是不可能達到理想狀況的,因為環境干擾、串音干擾等因素的存在使得線路的頻帶不可能被完全利用起來;因此,必須認真分析線路的噪聲信號的特性以及噪聲線路的模型,以便在編碼方式和調制方式中針對性的做一些改進措施以改善調制波形的抗干擾能力,使得傳輸速率能夠進一步提高。In this topic, the error characteristic of resistance voltage sensor was analyzed in theory, by using electric circuit analysis, the reasons which affected its error were gotten. based on theory analyses, initial structure was designed. then by using fem ( finite element method ) of simple resonance field, several structures electromagnetic field was calculated, and their amplitude errors, phase errors, maximum of electric field intensity and frequency characteristic of amplitude error were contrasted
本文從理論上分析了電阻式電壓傳感器的誤差,用電路分析法定性的研究了影響電阻分壓器誤差的因素;在理論分析的基礎上進行了電阻分壓器結構的初步設計;基於該設計,利用簡諧場的有限元方法進行了場的計算,比較了幾種結構方案的幅值誤差、相角誤差、最大場強值及其幅值誤差的頻率特性,從而得到一種最優方案;製作了分壓器樣機,並在本實驗室進行了實驗;最後,對電子電路部分進行了初步設計,並提出了抗干擾的措施。Abstract : since piezoelectric resonant filter can not effectively prohibit higher - frequency harmonic, the mechanism of this problem has been discussed by means of a specific example which shows that there exists lots of undesirable resonant frequencies of piezoelectric that would let pass undesirable signals. to solve this problem , an ameliorated electrostatic mechanical resonant filter is proposed and a specific case is demonstrated. the example of electrostatic resonant micro - bridge asserts that by adjusting the gap of exciting capacitance the higher - frequency vibrating model of micro - bridge cannot be excited based on orthogonal character of intrinsic vibrating shape of micro - bridge, so that this kind of resonant filter can effectively filter out undesirable higher - frequency harmonic
文摘:提出壓電諧振濾波器不能很好地濾除高頻諧波的問題,結合一個具體例子理論推導了壓電諧振濾波器存在許多干擾諧振頻率,從而不能有效濾除一些特定頻率的干擾信號.為了解決這個問題,提出一種改進型的靜電激勵諧振濾波器.為了說明其可行性,具體分析了改進型雙端固支微梁靜電激勵諧振濾波器,理論推導證實基於雙端固支微梁的各階振型正交的原理,通過適當調整激振電容的間距,雙端固支微梁的高階振動模態受到很好的抑制,因此這種諧振濾波器可以有效阻止濾波器中心頻率的高頻諧波的通過Since piezoelectric resonant filter can not effectively prohibit higher - frequency harmonic, the mechanism of this problem has been discussed by means of a specific example which shows that there exists lots of undesirable resonant frequencies of piezoelectric that would let pass undesirable signals. to solve this problem , an ameliorated electrostatic mechanical resonant filter is proposed and a specific case is demonstrated. the example of electrostatic resonant micro - bridge asserts that by adjusting the gap of exciting capacitance the higher - frequency vibrating model of micro - bridge cannot be excited based on orthogonal character of intrinsic vibrating shape of micro - bridge, so that this kind of resonant filter can effectively filter out undesirable higher - frequency harmonic
提出壓電諧振濾波器不能很好地濾除高頻諧波的問題,結合一個具體例子理論推導了壓電諧振濾波器存在許多干擾諧振頻率,從而不能有效濾除一些特定頻率的干擾信號.為了解決這個問題,提出一種改進型的靜電激勵諧振濾波器.為了說明其可行性,具體分析了改進型雙端固支微梁靜電激勵諧振濾波器,理論推導證實基於雙端固支微梁的各階振型正交的原理,通過適當調整激振電容的間距,雙端固支微梁的高階振動模態受到很好的抑制,因此這種諧振濾波器可以有效阻止濾波器中心頻率的高頻諧波的通過Assigning serial different address code to different subscribers, useful signal is taken out of the same time slot and frequence, and is transmitted with one share channel. at received end, system makes use of completed address code from sending end to do correlative check and take out useful subscriber signal. the other address code signals are treated as broadband disturbing signal which is removed. in radio environment of existing variable disturbtion and muti - way declining, expand frequence signal ’ s broadband characteristics can improve system performance obviously. cdma mobile telecommunication system has some better characteristics, such as anti - disturbing 、 anti - way declining 、 secrecy 、 capacity 、 utilizing rate of frequence resource and so on, than other mobile telecommunication system
Cdma ( codedivisionmultipleaccess )移動通信系統的技術基礎是基於擴頻技術的碼分多址,通過給不同的用戶分配各自特定的地址碼序列,將處于相同時隙和頻率的用戶信號分離開來,採用共享通道方式傳輸信息。在接收端,系統利用與發送端完全一致的本地地址碼對接收信號進行相關檢測,提取需要的用戶信號,而將其他使用不同碼型的信號視為寬帶干擾而從中剔除掉。It has been proven that the spread spectrum technologies have good capabilities of overcoming isi in electromagnetic wireless channel. the feasibilities of their applications to underwater acoustic channel have been analyzed, the frequency hopping technology is chosen. instead of using time - frequency diversity, convolutional coding and viterbi decoding are employed to combat signal fading, consequently the bit - rate and bit - error - rate performance of the underwater acoustic voice communication system can be balanced and controlled
由於擴頻技術在抗碼間干擾方面具有優良的特性,因此在分析了各種擴頻技術于本研究應用的可行性之後,確定了跳頻技術作為具體實現方案;在克服幅度衰落方面,選用卷積編碼和維特比譯碼方法來替代原有的分集技術以綜合調節系統的通信速率與誤碼性能,達到差錯可控的目的。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。In cellular envirorunents, because of the influence of several adverse factors, such as muitipath, non - line - of sight propagation, noise, interference and channel frequency characteristics, radio statistics measuremenis like tdoa, toa and aoa related to mobile position, the performance of location algorithms mny be significantly degraded and the position estimation of ms is inevitably biased
在蜂窩網路環境中,由於受多徑、非視距傳播、噪聲、干擾和通道頻率特性等多種不利因素的綜合影響,使tdoa 、 toa 、 aoa等與移動臺位置有關的電波特徵測量值不可避免地出現較大誤差,從而使各種定位演算法的性能顯著下降,造成移動臺位置估計出現較大偏差。The so - called automatic recognition of modulation ( amr ) schemes automatically classifies the modulation types from the samples of received signal by abstracting the related features such as amplitude, frequency, and phase, followed by employing proper recognition algorithms based on the fast digital signal processing techniques and advanced computing technology. the result of amr can be used in the following processing blocks such as demodulation, supervision processing and anti - interference processing and so on
所謂調制類型自動識別( amr )是根據接收信號樣本提取出振幅、頻率和相位的特徵參數,然後藉助信號處理技術和計算機快速處理能力,採用合理演算法進行處理,從而實現對未知已調波調制類型的自動識別,為后繼的解調、監控、抗干擾等處理奠定基礎。The characteristics of calls are closely correlated to the ecology of bats, for example, the dominant frequency influences the body size of bats " prey, the detecting range of bats ; the structure of calls decides bats " ability to detect prey in the complicated environment. therefore, the research on factors, which influence the structure and characteristics of ultrasound and on the mechanism by which bats detect and orient the prey will promote the understanding of the ecological behavior of bats
由於聲波的特徵和蝙蝠的生態行為有著密切的聯系,如聲波的主頻率影響蝙蝠可探測到的獵物的大小、獵物能被探測到的距離及獵物探測和躲避蝙蝠的能力,聲波的結構則影響蝙蝠在干擾環境中探測獵物的能力,因此研究影響蝙蝠聲波結構和特徵的因素、探討蝙蝠聲波探測和定位的機制,可以更加深入地了解蝙蝠的生態行為。分享友人