頻率擴展 的英文怎麼說
中文拼音 [bīnlǜkuòzhǎn]
頻率擴展
英文
frequency spread-
Based on the real situation of submarine and antisubmarine warfare ( asw ), according to the classical design theory of transducer or transducer array, a sonar will be researched and made, which has the feature of more wider bandwidth, more lower operating frequency, more lager radiation acoustic power, more farther operating distance, more higher researching efficiency and more higher directive accuracy
本文根據現代潛戰和反潛戰( asw )的實際情況,按照經典的換能器和基陣的設計理論,研製聲吶,旨在擴展其頻帶寬度、降低其工作頻率、增大其發射功率、擴大其作用距離以及提高其搜索效率和定向準確度。2. a frequency extrapolation scheme is developed to effectively predict radar cross section using floating genetic algorithm based on the geometrical theory of diffraction ( gtd ) model. the threshold discrete fourier transform ( tdft ) is introduced for the data compression in angle domain
在目標散射中心建模方面,我們將浮點型遺傳演算法( fga )應用於實際人工目標的gtd模型參數的抽取,利用所抽取的模型參數完成了雷達散射截面rcs的頻率擴展以及數據壓縮,並利用擴展的數據提高了距離解析度。An acoustic-emission pulse contains a very wide range of frequency components, extending up into the megacycle range.
聲發射脈沖就包含一個很寬的頻率組成范圍,可擴展到兆赫。Shortwave channel is time varying transmission channel. it has dispersion in frequency and time domains. this characteristics hinds the data transmi - ssion at high speed and the correction of received data. in this dissertation i have analyzed the statistic characteristic of shortwa - ve channel, established the model of shortwave channel and simulated the rayl eigh fading distribution. the technology of spreading spetrum has been proved that it has the capability for anti - multipath and discerning multipath
在短波通信中,由於通道的時間色散和頻率色散,引起多徑展寬和多徑衰落,前者限制了數據的傳輸速率,後者造成短波數據通信中出現突發錯誤,為了解決多徑效應對短波通信的影響,本文所做工作如下:首先詳細分析了短波通道的統計特性,建立其數學模型;其次分析了擴頻通信的特點,從理論上證明擴頻技術不僅具有抗多徑干擾能力,而且具有分離多徑的能力;介紹了傳統的rake分集合併技術的特點。It designed signal amplifying circuit, frequency tricking circuit, data sampling and keeping circuit. the choice of 12 bits high accuracy a / d integrated data sampling card made program simply, high flexible and expandable. and to each error which is likely to occur in high voltage capacity type equipment during the monitoring, analysis and judgement are given
在硬體電路實現上,注意選擇信號傳感器;合理設計了信號放大電路和濾波電路;設計了頻率跟蹤電路,數據采樣/保持電路;結合軟體控制選用了12位高精度的a / d轉換器,使軟體編程簡化且具有較高的靈和性和可擴展性。If the range of frequencies being absorbed spreads across the visible, the object w ill appear black.
若被吸收的頻率范圍擴展到整個可見區,那麼物體將呈現黑色。A parametric psychoacoustic model based on critical band rate, level - dependent spreading function, non - linear superposition and forward masking was proposed
摘要提出了基於臨界頻帶率、依賴于強度的擴展函數、非線性迭加和前向掩蔽效應的參數心理聲學模型。When signals pass high power amplifier, they would be distorted in amplitude and phase, leading to spectrum spread and distortion of in - band signals, both of which would weaken performance of the whole system in turn
在無線通信中,信號在通過高功率放大器時會產生幅度和相位失真,造成頻譜擴展以及帶內信號畸變,導致整個系統性能的降低。The research consists of several aspects as follows : the characteristics of uwac is analyzed, including the multi - path effect, the doppler shift effect, etc. then the mathematics " model of uwac is given
研究內容主要包括以下幾個方面: ?分析了多途時間擴展、多普勒頻率擴展等水聲通道的物理特性及水聲通道的數學模型。Two approaches to improve the robustness of the detector, each based on a different theirs distortion mechanism. one is based on the modeling as fast fading distortion ( ffd ) whose optimum detector is the segmented replica correlator ( src ). the second approach is replica correlation integration ( rci ) for time spreading channel ( tsd )
從頻率擴展通道( fastfadingdistortion , ffd )和時間擴展通道( timespreadingdistortion , tsd )的形成機理出發建立了目標回波的數學模型,指出ffd和tsd的最佳檢測器分別為分段副本相關器( src )和副本相關積分器( rci ) 。It mainly includes two parts : the frequency offset caused by the difference of the mobile equipment ’ s transmitting frequency and the nodeb ’ s receiving frequency ; the frequency offset caused by the vehicle of the mobile equipment, which is called doppler shift. accurate frequency offset estimation and compensation is of importance for demodulation
它主要由兩部分構成:由於nodeb (基站)和移動臺晶振本振頻率的不同而產生頻偏;由於移動臺運動產生多普勒效應,引起的多普勒頻偏,在信號功率譜上表現為多普勒頻譜擴展(以後簡稱多普勒擴展) 。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。The influence of frequency extension on software antenna algorithm selection
頻率擴展對軟體天線演算法選擇的影響Enhanced variable rate codec speech service option 3 for wideband spread spectrum digital systems
寬帶頻譜擴展數字系統用增強的可變率編譯碼器語音服務選擇3Evrc 3 software distribution for tia - 127 - a - enhanced variable rate codec speech service option 3 for wideband spread spectrum digital systems
Tia - 127 - a的軟體配置.寬帶頻譜擴展數字系統用增強的可變率編譯碼器Since the energy of 18 - information track signal is concentrated around upper frequency and lower frequency, the frequency of the modulation signal is low, and it must have high resolution, we use zfft to detect it. as the energy of um - 71 signal is more concentrated, we use extreme value method to detect the frequency of modulation signal in frequency domain, which can satisfy the frequency resolution
針對18信息軌道信號能量集中在上、下邊頻附近且低頻信息頻率低的情況,提出了用zoom - fft ( zoom指頻率擴展或細化,簡稱zfft )演算法進行信號的局部放大檢測低頻信息,以提高信號的頻率解析度,而um - 71軌道信號能量集中在載頻附近,在頻域上採用極值法檢測低頻信息,即可滿足信號頻率解析度的要求。Flex frequency level expander
頻率擴展器Multicarrier wireless communications have been widely investigated in the past decades. recently, two - dimensional spread spectrum ( 2d - ss ) system has drawn a lot of attention because of its full utilization of spreading characteristics in the frequency domain and time domain. compared with multicarrier code division multiplex access ( mc - cdma ), 2d - ss system can effectively mitigate multiple access interference ( mai ) due to spreading in the time domain
當前多載波無線通信技術得到了廣泛的研究,二維擴頻通信系統是近年來提出的新的擴頻通信方式,由於二維擴頻系統從時域和頻域上分別對數據信號進行頻譜擴展,因此它同時具有時域擴頻和頻率擴頻通信系統的特點,是對傳統的一維時域直接序列擴頻和多載波擴頻的推廣。Introduction to communication systems ? analysis and design of communication systems ; analog and digital modulation and demodulation, frequency conversion, multiplexing, noise and distortion ; spectral and signal - to - noise ratio analysis, probability of error in digital systems, spread spectrum
通信系統基礎:通信系統分析和設計,模擬和數字調制和解調,頻率轉換,統計復用,噪聲和失真;譜分析和信噪比分析,數字系統誤碼率,擴展頻譜。It follows that the description of characteristics of g programming language in labview and the process of building virtual instruments. the paper provides a new spectrum analyzing method of the combination of spread spectrum with fft. at last it gives the arithmetic realization and programming diagram of every part of spectrum monitoring and signal searching
介紹了labview下如何通過計算機介面獲取數據的過程,數據採集過程中各個參數的演算法選擇;同時闡述了labview平臺下g語言的特點及構建虛擬儀器的過程,然後介紹了信號分析處理部分採用的頻率擴展與fft相結合的頻域分析方法;頻譜監測部分各個模塊的演算法實現;最後給出了信號搜索部分的演算法實現及其原理框圖。分享友人