通信頻帶寬度 的英文怎麼說
中文拼音 [tōngxìnbīndàikuāndù]
通信頻帶寬度
英文
communication band width-
In all kinds of complicated network, oriented linking and unlinking, communication frequency resource is strained, and bandwith to transmitting audio frequency signal is too restricted, complicated and fluky, while audio frequency data exponential have been increased in the last several years. under the circumstances, based on the research of predecessor, this paper studies wavelet analysis ' s maths gist and practices significance on signal process, and puts forward a optimized wavelet package condensation arithmetic to process audio frequency data, which gives attention to coding efficiency, multirate and compression delay. simulation experiment on the arithmetic has been done by matlab
針對無連接和面向連接的各種復雜網路環境下,通信頻帶資源緊張,音頻傳輸帶寬有限且復雜多變,而各種音頻數據又日益增多的局面,本文研究小波分析在信號處理方面的數學依據和在數據壓縮方面的實際意義,在前人不斷工作的基礎上,提出了一種優化小波包變換編碼方案用於音頻數據的壓縮演算法,兼考慮了編碼效率、多碼率和壓縮時延多個方面,並在matlab環境下做了模擬實驗,對各種音頻信號及多種小波函數做了模擬結果比較,實驗結果證明該演算法可以在一定計算復雜度下可以很好地改進壓縮效果,達到多碼率下實現實時編解碼的過程,在高速dsp晶元等硬體設備支持下,可以有效應用於實際復雜多變信源編碼。Isar transmits wide bandwidth signals to obtain high range resolution. the cross - range resolution is obtained by the doppler frequency information of the target ’ s rotation
逆合成孔徑雷達通過發射大帶寬信號獲得好的距離解析度,利用目標相對于雷達的轉動產生多普勒頻率梯度來獲取好的方位向分辨力。The clues and techniques to improve the resolution of data processing are 1 ) removing the affection of near surface factors on data acquisition, including static correction and noise eliminating technique etc, 2 ) broadening the frequency band of pre - stack seismic data, including amplitude compensation and pre - stack deconvolution etc, 3 ) improving s / n ratio of high frequency and weak reflection signals through multiple coverage with high precision velocity analysis, residual static correction and high - order nmo, raising " dead line of high frequency reflection ", and 4 ) identifying post stack effective reflection frequency band, enhancing dominant frequency and so on
主要包括:消除近地表因素對資料採集的影響,包括靜校正和噪音壓制技術等;疊前拓寬地震資料領帶,包括振幅補償和疊前反褶積技術等;藉助高精度速度分析、剩餘靜校正和高次項nmo技術,通過多次覆蓋疊加,消除資料中隨機噪聲干擾、提高資料信噪比,尤其是高頻端反射信息的信噪比,改善高頻反射和弱反射信號信噪比,提高「高頻反射死亡線」 ;疊後有限反射頗帶識別、抬高優勢頻率等。By using optical cable communication methods, which have advantages of great information transmission capacity, rapid velocity, wide frequency band, strong anti - jamming capability, low circuitry loss and easy construction, modern sky - wave over - the - horizontal radar can achieve information transmission and system control of full coherent radar, which has excellent abilities of security, stabilization, anti - jamming and anti - destruction
通過採用光纖傳輸技術,利用其信息傳輸容量大,速度快,頻帶寬,抗干擾能力強,線路損耗低,易於施工等特點,實現全相參雷達的信息傳輸和系統控制,具有優良的保密性,穩定性、抗干擾性和抗摧毀能力。The spot responder system which is the necessary part of ctcs is analyzed in the dissertation and three key technologies of the channel in the responder system are researched. firstly, a new kind of rectangular plate magnetic inductive loop antenna is designed to transmit the power frequency. researching the near field inter - inductive characters, the relationship among the inductive efficiency, the perimeter and the conductor width of the antenna is found out
本文在對ctcs中的點式應答器系統原理及組成進行分析和消化的基礎上,對系統中通道的幾個關鍵技術進行了詳盡的研究,主要分為三個方面: 1 ,提出並研製了新型的片式環形磁感應天線,並對傳輸能量載波的天線的近場互感特性進行了分析,得到互感效率隨天線的周長大小以及導帶寬度的變化規律,並通過計算機模擬和試驗對天線的近場波瓣圖進行了研究;通過分析寬帶匹配技術中的實頻法理論,設計了信號載波天線的寬帶匹配網路。Secondly, ground on the duct noise control, the delayed - lms algorithm, which is actulized easily, is brought forward, then the simulation on pc is achieved. it is shown from the computer simulation that for the single frequency noise, there will be a good effect when choosing the suitable parameters ; but for the narrowband noise, the effect will become worse with increasement of the bandwidth. this result is helpful to analyze the parameters influencing anc
結果表明: ( 1 )隨著濾波器長度的增大,系統收斂速度變快; ( 2 )隨著值的增大,系統的收斂速度增大,但是當值超過某一范圍時會引起系統的發散; ( 3 )次級通路的延遲數與初級噪聲頻率有關; ( 4 )對于窄帶信號, dlms演算法可以取得一定的降噪量,但是隨著窄帶信號帶寬的增大,降噪效果明顯變差。Because gyrotron traveling wave tube amplifier ( gyro - twt ) is an important millimeter wave amplifier with the characteristics of the high output power, the broadband width, and good efficiency, which has vast application vistas in many areas such as millimeter radar, communications, electronic countermeasure, and so forth, it has been pay much respect in the world
迴旋行波管是一種大功率、高效率、寬頻帶放大器,在毫米波雷達,通信與電子戰等方面有十分重要的應用前景,因而在國際上受到高度重視。由俄羅斯人g . denisov等提出的螺旋波紋波導是一種比較理想的結構。The frequency band extension with time base jitter is also studied by simulation. the results show that the compensation of time jitter can reduce the error of signal and then increase the accuracy of frequency band extension
對時基抖動的頻帶展寬技術的模擬結果表明,通過擴展的概率密度法對時基抖動的補償,可以減小信號的誤差,因而提高頻帶展寬的精度。With the characteristics of large ambient noise, very narrow bandwidth, low carrier frequency, great propagation latency and time - space - frequency variant multipath effect ( mpe ), the stochastic ocean channel has demonstrated the greatest complexity and difficulty for underwater acoustic wireless communications. among them multipath effect ( mpe ) is the most difficult obstacle that results in signal fading and inter - symbol interference ( isi )
但是噪聲高、帶寬窄、載波頻率低、傳輸時延大、多途徑效應隨時間?空間?頻率變化等通道特性都會給有效、可靠的水聲通信帶來很大的麻煩,其中多途徑效應是最主要的困擾因素,它會導致信號幅度衰落和碼間干擾。As a high band - efficiency digital modulation scheme, dvbc ( digital video broadcasting of cable ) qam ( quadrature amplitude modulation ) modulator is widely adopted in the wide - band communication area, such as hdtv broadcasting, cable modem, microwave communication, satellite communication and so on
正交幅度調制器( qammodulator )作為一種高頻譜利用率的數字調制方式,在高清晰度電視( hdtv )廣播、 cablemodem 、固定寬帶無線接入、衛星通信、數字微波傳輸等寬帶通信領域得到了廣泛應用。The standard is designed to give a new technical solution for a broad range of applications, such as very low bit rate conversational services and entertainment quality broadcast, interactive video - on - demand services etc. for the enhancement of the coding efficiencies, the new standard adopts new tools as following : multiple reference pictures, variable block - size with seven block sizes in motion prediction, quarter - pixel accuracy for motion vector, short word - length integer transform, context - adaptive entropy coding and loop filter deblocking
H . 264 / avc標準支持從低帶寬、高誤碼率的無線移動視頻通信到高帶寬、低誤碼率的有線視頻廣播等多種應用,因此,日益受到業界的關注。為了實現更高的編碼效率, h . 264 / avc標準採用了很多新的編碼技術,如多參考幀預測、多尺寸編碼塊模式、 1 / 4像素精度運動矢量、整數變換量化、基於內容的熵編碼、新型幀內預測、去除方塊效應的濾波器等。The vertical delay stacked source obtains optimum matching with wall rock by controlling the charge mode and the excitation velocity, and maximum utilizes its energy. thus the seismic signal with the high frequency abundance and frequency bandwidth wide be obtained
垂直延遲迭加震源通過控制裝藥方式和控制炸藥速度來達到與圍巖的最佳匹配,最大限度的利用其激發的能量,激發出高頻成份豐富、頻帶寬、高頻能量高的地震信號。One new method that the uwb signal can be received ambiguously has been presented in this dissertation. furthermore, the sampling lfm signal becomes two sine signals with different frequencies based on two different delay processes. based on fft and remainder algorithm, the modulation rate and initial frequency of sub - sampling lfm signal are estimated precisely and unambiguously in negative snr
該方法通過在數字域對信號進行兩路不同的延時和余數定理實現欠采樣條件下超寬帶線性調頻信號的調制斜率和初始頻率的無模糊估計,在不降低參數估計精度的前提下,解決了欠采樣方法引起硬體復雜度增加的問題。This task uses the ds - ss technology, and researchs the important technologies, such as synchronization of ds - ss, rake receive, narrow - band interference suppression, etc. these technology are useful for the voice - band channel of hf. i designed one system of very low bit rate for hf data communication, and completed the softwave module design of the system. i get the result of system ' s simulator, it ' s useful for the system realization
根據短波音頻帶寬通道的特點,重點對系統的擴頻同步技術、 rake接收技術和窄帶抗干擾技術進行了專題的研究。並根據自己多年的科研經驗,設計了一種具有實際意義的短波最低限度通信系統,並對實際的軟體實現進行了模塊化的設計。In next mobile communication system to suffice more and more high - speed data service and demand of qos ( quality of service ) many new wireless link layer transport technologies are going to be used such as mimo ( multiple input multiple output ), ofdm ( orthogonal frequency division multiplexing ), channel coding and acm ( adaptive coding modulation ) etc. low density parity check ( ldpc ) codes were first discovered in 1960 ’ s which belong to linear block codes with their parity matrix being sparse
下一代移動通信系統為了滿足移動用戶對高速、寬帶數據傳輸業務不斷增長和更高服務質量的要求,採用了許多新的無線鏈路傳輸技術,包括多天線發射和接收技術、正交頻分復用技術、通道糾錯編碼技術和自適應編碼調制技術等。上世紀60年代提出的低密度校驗碼,是一種校驗矩陣為稀疏矩陣的線性分組碼。In this paper, a new advanced general wide - band signal generator module is developed, which uses high speed fpga as its control - unit. the module can work in any system with different bandwidth and can generate any kind of lfm signal, whose bandwidth is less than 200mhz, and time - width is less than 870us
該模塊具有標準的輸入輸出介面,不同波段、不同帶寬的雷達系統均能直接使用,可以產生帶寬200mhz以內、脈沖寬度870us以內的線性調頻信號,具有預失真功能,能補償系統的特性特性失真,還可直接通過4倍頻或8倍頻實現帶寬的擴展。But they have the disadvantages such as poor complexity, poor security and insufficient amount of sequence numbers among the family of codes, the chaotic signals have noise ? ike, broadband frequency spectrum, they can be used as spreading codes, furthermore, chaos system is extremely sensitive on initial conditions so that the various initial conditions given by chaos system can provide with large sum of spreading sequences and this can meet the demand of cdma, this thesis sets out to study on using chaos system to generate spreading sequence s, there are two parts is this paper : firstly, we study the basic theory of spread ? pectrum communication and the characteristics of chaos so as to prove the applicability of chaos system to be used in spread ? pectrum ii communication system
現在使用的擴頻碼有m序列, gold碼和r - s碼等,這些擴頻碼具有良好的隨機性,但普遍存在著復雜度低、保密性差以及同一碼族序列數目少等缺點。混沌信號具有類似噪聲、寬帶連續頻譜的特徵,正符合擴頻通信中對擴頻碼的要求,而且混沌系統對初始值極其敏感,可以通過給混沌系統賦予不同的初始值得到為數眾多、不相關的擴頻序列,這正好滿足碼分多址的要求。本文對利用混沌系統應用於擴頻通信作了一些研究工作,主要包括兩部分:第一部分:探討了擴頻通信的基本理論和混沌的基本特性,說明將混沌系統應用於擴頻通信系統的可行性。Its main characteristics include the following parts : ( 1 ) the trait of matching of network, as it manages the information of peers by grouping according to their location in the internet ; ( 2 ) easy to implement, as it distributes the video data according to the need of peers, and does not have to maintain a complex global structure ; ( 3 ) robust and resilient, as it can adapt the complex and dynamic environment of network very well ; ( 4 ) good expansibility, as it has better performance with the increase of users ; ( 5 ) high utilizing of bandwidth, as it can control the peers according to the change of bandwidth of them and make good use of their bandwidth ; ( 6 ) low delay of peer to peer, as it considers the delay among peers sufficiently besides the bandwidth, and makes the delay of peer to peer is low
該視頻流媒體網路模型在網路帶寬效率、延遲和可靠性之間做出了很好的平衡,它的主要特點有: ( 1 )網路匹配特性,使用終端用戶的網路位置信息來對節點進行分組管理,對節點間的鄰近度進行優化; ( 2 )易於實現,根據數據的流向來分發視頻流媒體數據,不需要維護復雜的數據結構; ( 3 )適應性強,能很好的適應復雜變化的網路環境; ( 4 )擴展性好,加入視頻流媒體網路中的用戶越多,性能越好; ( 5 )帶寬利用率高,及時對每個節點的帶寬變化情況進行控制,充分利用空閑帶寬; ( 6 )端對端延遲小,通過在帶寬和延遲之間達到平衡使得端對端延遲減小。Orthogonal frequency division multiplexing ( ofdm ) has been widely used in many systems such as digital audio broadcasting system ( dab ), digital video broadcasting system ( dvb ), high definition tv ( hdtv ) and wireless local network. ofdm will be critical technique in broadband wireless mobile communication system in future
正交頻分復用( ofdm )技術已經被廣泛應用於數字音頻廣播、數字視頻廣播、高清晰度電視、無線局域網等系統中,在未來的寬帶無線移動通信系統中, ofdm也將是一項必不可少的技術。分享友人