短波時號 的英文怎麼說
中文拼音 [duǎnbōshíháo]
短波時號
英文
hf time signal- 短 : Ⅰ形容詞(空間、時間兩端之間的距離小) short; brief Ⅱ動詞(缺少; 欠) lack; owe Ⅲ名詞1 (缺點) we...
- 波 : Ⅰ名詞1 (波浪) wave 2 [物理學] (振動傳播的過程) wave 3 (意外變化) an unexpected turn of even...
- 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...
- 號 : 號Ⅰ名1 (名稱) name 2 (別號; 字) assumed name; alternative name3 (商店) business house 4 (...
- 短波 : [電學] sw (short wave); high frequency wave
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The other research purpose is to discover characteristic information and reliable methods of reflecting spinal cord damage. due to typical damage indicators, amplitude and latent period, have bugs such as limited information and weak stabilities, this project recommends applying time - frequency analysis to monitoring spinal cord function. through analysing and comparing typical signal with stft and cwt, it is proved indicators under time - frequency distribution can be better in reflecting signal changes, espcially the wavelet transformation
針對目前ep監測中判定脊髓損傷的指標(波幅和潛伏期)存在信息量相對較小、穩定性較差的缺陷,本課題提出利用時頻分析技術對術中脊髓功能監護進行研究,通過短時傅立葉變換和小波變換分析和比較典型信號的時頻分佈,證明時頻特徵參數能更有效的提取信號的變化信息。Abstract : to obtain the high frequency ( hf ) array signals, an applied circuit called hf array signals generator is designed using dsp and duc ( digital up converter ). the generator simulates the generation of output signals of 9 - element arrays with different array format, different direction of arrival ( doa ) and existing cochannel signals respectively
為了在實驗室中獲得短波天線陣列信號,應用dsp晶元和duc晶元(數字上變頻器)設計了一個實用電路短波陣列信號發生器,模擬實現了短波九元天線陣的多種陣型、不同來波方向及存在同頻多信號時的陣列輸出信號。Chapter 1 introduces the extensive application of hf / vhf communication and hf / vhf radios in military field, and points out the significance for promoting the research work of fh communication countermeasure using modern signal processing techniques, especially time - frequency analysis
第一章介紹了短波通信和短波跳頻電臺在軍事領域中的廣泛應用,以及現代信號處理技術特別是時頻分析技術對促進跳頻通信對抗研究的重要意義。In modern shortwave communication, the length of signal existence time in single channel is very short for reducing the probability of being intercepted, thus the difficulty of signal detection and extraction increased
摘要在現代短波通信中,作為低截獲率通信手段之一,單個通道內信號持續時間大大縮短,從而增加了信號檢測與提取的難度。The results show that the self - adaptive filter can be used to detect line spectrum, the wavelet transform and the fourier transform can be used to detect the ship noise in modulating the anisotropic noise field
結果表明:自適應濾波對于各向異性噪聲場中的線譜檢測有良好的效果;而小波變換和短時傅里葉變換對各向異性噪聲場中的艦船噪聲調制信號檢測有良好的效果。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。In a tdma network, multiple users share the common medium ( or channel ) and bandwidth but different intervals of time. in case of the burst mode, the carrier of the modulated signal needs to be synchronized in a very short time. the common approaches such as a costas - loop and so on are no longer suitable any more
在一個時分多址( tdma )通信網路中,多個用戶通過不同的時間段共享一個傳輸線路(或者通道)的帶寬資源,每個用戶只能在分配給自己的時間段內進行通信,這種突發方式信號的解調要求載波恢復要在很短的時間內完成,我們以往在連續信號解調器中採用的costas環等方法很難適應這種要求。In this paper, the self - adaptive filter, the wavelet transform and the fourier transform are used to detect the stationary and the non - stationary signal of underwater sound in anisotropic noise field
本文以各向異性噪聲場為例,分別對聲矢量信號中的聲壓、振速探討應用自適應濾波、小波變換、短時傅里葉變換檢測水聲平穩和非平穩信號的應用效果。The computer simulations show the validity of the models. 3. joint estimation of the time delay and doppler frequency based on short - time fourier transform ( stft ) and time - frequency analysis are studied to estimate the parameters of the underwater target echo
針對主動回波信號參量的估計問題,重點研究了利用短時傅立葉變換、時頻分析進行時延和多普勒頻移聯合估計,進而進行目標距離和速度參數的估計。From three - wave coupling equations, the optimal crystal length, conversion efficiency and parametric light pulse width are computed numerically when clbo is used in picosecond optical parametric amplification. the results present that clbo are suited for optical parametric amplification in short wave band. in order to get higher conversion efficiency, the crystal length should be optimized according to the intensities of pump and signal waves
從三波耦合方程出發,對clbo用於皮秒級光參量放大時,最佳晶體長度、轉換效率和參量光的脈沖寬度進行了理論分析和數值模擬,結果表明clbo晶體適合在短波范圍作光參量放大,為達到高的轉換效率和窄脈寬的信號光輸出,泵浦光和初始入射信號光的強度應根據晶體長度取最優化值。This paper gives a time - synchronization technique bases on gps time service signal which is used in broad band seismic recorder 。 by world coordination time offered by gps - - utc ( usno ), adjust local clock base on gps signal, gain high nicety clock signal, clock precision reachs 10 - 6 。 this clock is the time source of broad band seismic recorder, bring the whole seismic recorder works in same time base. 1pps time base with high stability can be used as in - phase, spring, time and start - stop of every collection mode, while the scale under second make a precise time mark to receive data of broad band seismic recorder
針對接收機中gps信號的噪聲進行kalman濾波軟體處理, kalman濾波可以對gps信號與本地晶振時鐘的時差數據在大噪聲中進行平滑,在較短時間內估計出高精度的時差數據。系統消除了gps秒脈沖信號的ms級隨機誤差,把晶振秒脈沖的長期穩定度鎖定到gps信號的穩定度上;在gps信號失效時給出了可行措施,能夠保證在任何情況下產生一個穩定、高精度秒脈沖信號,誤差在1 s內。Based on the different work states of engine, the engine vibration signal collected in it ' s steady work conditions is analysed by the technique of confrequency spectrum ; the signal related to the fast run - up state is processed by stft and wavelet analysis
根據發動機的工作特點,將振動信號分為穩態振動信號和過渡態振動信號。穩態信號採用傳統的傅立葉分析方法,過渡態信號採用了短時傅立葉變換和小波方法。Based on the character of short - time non - stationary random signal, the feature of energy distribution of multi - interval - time in millisecond blast signals was investigated by means of the wavelet packet method
摘要根據爆破振動信號具有短時非平穩的特點,利用小波包分析技術對滿足分析要求的多段微差爆破振動信號的能量分佈特徵進行研究。There are three main reasons attributed to this result as follows : firstly, i choose a wavelet transform named fivezhu wavelet <, which is different the other wavelets from the fact that fivezghu wavelet have seven 7 sample points and was decomposed a orthogonal, two - band filter bank and include a detailed part ; which can be realized by two orthogonal mirror symmetries lattice filter
為此我主要做了以下方面的工作:首先,是小波基的選取,因為小波基的選取不同於短時fourier變換。選取不同的小波基對同一圖像信號處理會得到不同的結果,就目前的幾種小波基。我選擇了五株形小波。A hybrid method for prediction of solids holdup in gas - solid circulating fluidized bed is proposed based on chaos phase reconstruction and wavelet package as well as neural networks. experimental results show that the model provides good predictions and has promising applications
氣一固循環流化床的顆粒濃度時間序列預測結果表明,小波、混沌和人工神經網路結合預測模型可有效地用於氣固循環流化床局部顆粒濃度波動時間序列信號的短期預測。Generation of multi - wavelength signals and ultra - short pulses are of great importance for a wide range of applications such as in wavelength - division - multiplexed ( wdm ) and optical time - division - multiplexed ( otdm ) fiber communication systems, fiber sensing, nonlinear optics, optical instrument testing, and time - resolved spectroscopy
密集波分復用( dwdm )和光時分復用( otdm )是實現光纖通信系統升級擴容的有效途徑,而多波長信號及高重復頻率的超短光脈沖的產生則是與其相對應的兩種關鍵技術。Digital receiver and its forepart operational principle are discussed, then methods of instantaneous autorelation, short - time fourier transform, wigner distribution and wavelet analysis are introduced in detail. the advantages and disadvantages and the application range of these algorithms are given. based on the merits of these algorithms, a new method for signal modulation type analysis is presented
本文討論了數字接收機以及前端的工作過程,然後詳細闡述了瞬時自相關、短時傅立葉變換、 wd演算法、過零檢測和小波分析等各種演算法在脈內調制分析上的應用,分析了各演算法的優缺點,提出一種并行處理模式:即針對不同的信號採用不同的演算法對脈內調制信號進行分析。The system is compatible with the various different types a / d converters, carry out the functions of the vibration signal sampling, the saving of data file, the timely wave showing, the configuration table edit, the former data return and data analysis etc. the functions of signal analysis include the time field statistics analysis, the time field mutual analyzing, the frequency spectrum analyzing, the relevant analysis, the transmission function analysis, the demodulating analysis, and the short fourier transformation of the time and frequency field etc. experiments verify that the system carry out stably and credibility, various functions is achieved, has precise analyzing results, high calculating speed and high precision, the expected targets have been reached
該系統可以兼容多種不同型號的數據採集設備,實現了振動信號的採集、數據文件的存儲、波形的實時顯示、組態表編輯、歷史數據回放與數據分析等功能。系統的信號分析功能包括時域統計分析、時域相關分析、頻譜分析、相干分析、傳遞函數分析、解調分析以及時頻分析中的短時傅立葉變換等。經試驗驗證表明,系統運行穩定可靠,各項功能工作正常,數據分析結果準確、運算速度快、精度高,達到了預期設計目的。Simulator presented in this paper provides a direct interface for the test of shortwave communication system, which well represents various features of hf channel such as multi - path delay, rayleigh fading, doppler shift, doppler spread, gaussian noise and impulsive interference, etc. in order to realize the channel simulation for the intermediate frequency signal, we, inspired by the idea of soft - defined radio, bring forward a new design method that the channel simulator consists of several dsp chips
本文研製的模擬器提供介面直接對短波通信系統進行測試,能夠全面反映短波通道的多徑時延、瑞利衰落、多普勒頻移、多普勒擴展、高斯噪聲和脈沖干擾等特性。為了實現對中頻信號的通道模擬,開發出一個結合軟體無線電思想的由多個數字信號處理晶元構成的短波通道物理模擬器。Effects of current passing through the human body. part 2 : special aspects. chapter 4 : effects of alternating current with frequencies above 100 hz. chapter 5 : effects of special waveforms of current. chapter 6 : effects of unidirectional single impulse currents of short duration
通過人體的電流的效應.第2部分:特殊信號形式.第4章:頻率在100hz以上的交流電的效應.第5章:特殊波形電流的效應.第6章:短時間單向脈沖電流效應分享友人