aliasing frequency 中文意思是什麼
aliasing frequency
解釋
混疊頻率-
Frequency response, quantization noise, reconstruction error and its sensitivity to mismatch among adcs are studied at length in prqmf banks adc system, and the theoretic results include : ( 1 ) the distortion / aliasing functions of hybrid filter banks adc system is similar with that of switch capacitor filter banks adc system ; ( 2 ) for wide or narrow band input signal, the effective resolution of the two adc systems is 0. 51og2m bits higher than their adc ; ( 3 ) reconstruction error ' s sensitivity to mismatch among adcs of the two adc systems is reduced effectively than time interleaved adc system
2對prqmf濾波器組adc系統的頻響、量化噪聲特性、重建誤差特性以及重建誤差對adc間的失配敏感性進行了理論分析研究，所得到的理論結果為： （ 1 ）混合濾波器組adc系統與開關電容濾波器組adc系統的失真/混迭函數一致； （ 2 ）無論輸入寬帶還是窄帶信號，這兩種adc系統的有效解析度均比其adc提高了0 . 5log _ 2m比特； （ 3 ）這兩種adc系統的重建誤差對其adc間的失配敏感性均明顯低於時間交織adc系統。 -
To detect transient signals under complex background, a novel method of aliasing - free exponential bilinear time - frequency distribution is presented in this paper, which can avoid the frequency aliasing and information loss existing in the traditional bilinear distributions, reduce the cross - terms effectively and possess high time - frequency resolution
摘要針對復雜背景條件下瞬時信號的探測，提出一種新的無混疊雙線性時間頻率分佈方法，該方法能夠避免常用的雙線性時頻分佈中的頻率混疊與信息丟失，有效減小交叉項干擾，而且具有較高的時頻解析度。 -
The non - aliasing frequency and non - ambiguous 2 - d angles is obtained by the phase characteristic of eignevalue and integral search method in this dissertation, an algorithm of spatio - temporal 2 - dspectra estimation based on 4th - order cumulants was introduced and used to realize a prototype scout, a calibration algorithm in the wide - band array system is proposed
本文主要介紹了基於四階累積量的時-空二維譜估計演算法，並以此為基礎來實現時頻空三維偵察機；寬頻段陣列系統各種誤差參數的校正演算法，實驗系統的硬體驅動程序的開發和應用軟體的開發。 -
Moreover, sampling at high frequency eliminates the need for abrupt cutoffs in the analog anti - aliasing filters. a technique of noise shaping is used in - converters in addition to oversampling to achieve a high - resolution
由於在- a d轉換器中使用噪聲整形技術和過采樣技術，可以用一個簡單的模擬電路加上復雜的數字電路使整個a d達到一個很高的轉換精度。 -
It mainly includes following aspects : in this paper, firstly implication of wavelet analysis in signal harmonic component extraction is presented in detail, and on this foundation signal given frequency band component extraction method is proposed. then we investigate frequency aliasing phenomenon, reason why frequency aliasing phenomenon is easy happened when wavelet is implied in field of motor fault diagnosis, and frequency bands where frequency aliasing phenomenon is easer happened, and put forward approved morlet wavelet analysis method which can effectively alleviates frequency aliasing phenomenon. third we set up vibration signal detected system, design experiments to obtain three groups of fault signals : eccentricity fault, mixed fault of eccentricity plus mild rub, mixed fault of eccentricity plus moderate rub, and process these data using analysis method proposed in this paper
首先對論文的選題以及相關背景進行了探討，並對相關的小波基礎理論進行了闡述，主要針對感應電動機的偏心故障和偏心+碰摩復合故障形式及相關的應用演算法進行了詳細探討，主要工作內容包括下面幾個方面:在論文中，首先對小波分析在信號的諧波分量提取中的應用進行了研究，在此基礎上，提出了信號的特定頻帶成分的提取方法;研究了小波分析的頻域混疊現象，探討了小波分析應用於電機故障診斷領域時易發生頻域混疊現象的原因，以及混疊現象較易發生的頻帶，提出了可以有效減輕頻域混疊現象的改進的morlet小波分析方法;搭建了振動信號檢測系統，設計實驗採集得到三組故障數據:偏心故障，偏心+輕微碰摩復合故障，偏心+中度碰摩復合故障，並對這些數據應用本文提出的分析方法進行信號處理，提取出的特徵參數可有效區分這兩種故障形式;研究了基於matlab和labview的混合編程方法，完成了電機故障檢測系統的軟體開發。 -
Author suggests that increasing number of measurement taps and prolonging sampling time and enhancing sampling frequency will decrease signals aliasing and leakiness
並提出在進行壓力脈動試驗時，應增加測點、延長采樣時間、提高采樣頻率以避免信號遺漏和信號混疊等現象的發生。 -
From theoretical analysis, we know the existing demodulation methods have limitations as following : one is that the subtraction of the two signals frequencies will display as the result of demodulation when we demodulate two time - domain adding signals without modulating information ( fault information ) ; the other one is that aliasing phenomenon will occur as a result of getting absolute value, detection or square in the process of generalized demodulation analysis, such phenomenon will result in some superfluous frequency composition on the frequency spectrum, which will puzzle the detec tion of mechanical vibration. if the sampling frequency is selected from a suitable range, the aliasing phenomenon will be avoided ; the last one is that aliasing frequencies will be produced in zoom demodulation analysis because this algorithm cannot employ digital low - pass filtering to avert the folding frequencies of higher harmonics in the process of zoom sub - sampling
現有的解調分析方法存在以下三種局限性：將不包括調制信息（故障信息）的兩時域相加信號，也以其頻率之差作為解調信號而解出；廣義檢波濾波解調分析中，由於取絕對值、檢波或平方過程可能產生混頻效應，在解調譜中表現為無法分析的頻率成分，並由此推導出避免這種混頻現象的采樣頻率的選取范圍，從根本上避免此類誤診斷的產生；幾種細化解調分析新演算法中，因為無法在細化分析的選抽時進行數字低通濾波，有可能會出現調制頻率的高次諧波成分發生頻率混疊而反折到低頻部分的現象。 -
This dissertation analyses problems of profile aliasing and redundance in chirp - subpulse stepped frequency signal, points out that these problems are resulted from different parameters of chirp - subpulse stepped frequency signal
還對chirp子脈沖頻率步進信號中距離像的混疊和冗餘問題進行了分析，指出這些現象是chirp子脈沖頻率步進信號對不同參數的選取引起的。 -
This dissertation summarizes the method to select parameters of chirp - subpulse stepped frequency signal, presents a method to resolve profile aliasing and redundance in chirp - subpulse stepped frequency signal by the target pick - up algorithm and selecting parameters
文中總結了chirp子脈沖頻率步進信號參數選取的方法，提出了採用參數選取和目標抽取相結合的方法來解決chirp子脈沖頻率步進信號中距離像的混疊和冗餘問題。 -
Study the spectral de - aliasing method of image restoration in frequency domain, and offer the improvement with block processing and recursive rstoration to some problems. at the same time, the biased estimate theory is applied in the restoration processing. these improved steps increase the value in the use of data and decrease the time of computation
2 、研究了基於頻率域的解頻譜混疊方法，針對該方法存在的問題，分別提出了分塊重建和循環重建，提高了重建的效率；並將有偏估計用於重建理論中，提高了影像數據的利用率。 -
As a result, digital images usually suffer from aliasing due to undersampling, loss of high - frequency detail due to relative motion or out - of - focus. supperresolution involves up - conversion of the input sampling lattice as well as reducing or eliminating aliasing and bluring
因此，通常數字圖像因欠采樣（ undersampling ）而引起的信號混疊，因低解析度傳感點擴散（ psf ： pointspreadfunction ）而造成的高頻部分、丟失，以及因相對運動或散焦造成的光學模糊等因素而受損。 -
If the sampling frequency is less than this, we can expect a serious distortion of output frequency which is generally referred to as aliasing.
如果取樣頻率小於此數，那麼輸出頻率就要產生嚴重畸變，通常假頻指的就是這種情況。 -
Combining the hardware and software, the real - time performance is also discussed. ( 5 ) when the system is debugged, some problems are discussed in detail and solved, such as volts d. c of the input signal caused by a / d converter and aliasing in frequency spectrum arising as re - sampling input data. experimental results show that the performance of the system is satisfactory
（ 5 ）討論了本dsp系統的軟、硬體調試方法，並詳細地討論了在系統總體調試時，出現的各種問題? ?如a d器件引起的輸入模擬信號的直流偏置、波束形成過程中由於數據抽取引起的頻譜混疊，解釋和說明各種問題出現的原因，並提出了相應的解決方案。
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