frequency-shift system 中文意思是什麼
frequency-shift system
解釋
頻率移位制-
Jhs - d shift frequency aptitude transmitter mixer : system introduction
海之升數字移頻擴聲系統簡介： -
Sound system equipment. part 9 : artificial reverberation, time delay and frequency shift equipment
音響系統設備.第9部分:人工混響延時和頻移設備 -
Sound system equipment - methods for specifying and measuring the characteristics of artificial reverberation, time delay and frequency shift equipment
音響系統設備.第9部分:模擬混響滯后和頻移設備特性的規定和測量方法 -
The ideal power system needs to be supplied with sine voltage whose frequency and amplitude are both stable. to three - phase ac power system, the currents and voltages must be equal of amplitude and the phase - shift between each other should be 120 of positive order
理想的電力系統要求以頻率和幅值穩定的正弦電壓進行供電；對於三相交流電力系統，各相電壓和電流應處于幅值大小相等、相位互差120的正序對稱狀態。 -
Through utilizing the shift multiplication characteristics of m series, this kind of radar system eliminates the bad effect of doppler frequency. in theory, the doppler tolerance of the radar system can reach the half of the code rate with proposed echo pretreatment method in this paper
從理論上說，應用於該雷達系統的信號處理方法可以使得雷達系統的多普勒容限達到偽碼子碼重復頻率的一半，從而使偽碼調相雷達可以有效地發現高速目標。 -
By means of controlling accurately temperature of f - p cavity used in the frequency - stabilizing system of laser, the frequency stability of laser is significantly improved. especially the long - term unidirectional frequency shift is essentially overcome
從實驗結果，我們得出將作為頻率標準的f ? p腔精密控溫與對該腔不控溫對激光器振蕩頻率進行鎖定的結果相比較，清楚看到短期穩定性有一定提高，重要是對作為穩頻標準f ? p腔精密控溫，消除了由於溫度變化引起的頻率慢漂移。 -
Dsp digital shift frequency sires is new generation conference system and teaching equipment, which adopts dsp technology. it can lock the point of howl a automatically, dsp digital shift frequency and aptitude mix sound of transmitter
數字自動濾波器，數字話筒智能混音器，數字高低音調節器等多項數字化音頻處理模塊的技術優勢，解決了會議教學擴聲中的聲反饋問題，可提升話筒靈敏度 -
After all, why not just wire the entire sensory system for high - resolution input and eliminate the need to constantly shift the eyes, star, or echolocation frequency
說來說去，何不將整個感覺系統都裝配成高解析度的接收器，就可以免除不斷移動眼睛、星鼻或改變回聲定位頻率的麻煩？ -
This dissertation, basing on simulation, makes a deep research on simulating signal of gmsk ( gaussian filtered minimun frequency shift keying ) baseband modulation and demodulation in ais ( automatic identification system ) equipment. the technology related in the following makes the modulation and demodulation of baseband signal into realization by ti dsp, at the same time, provides a key technique to develop ais system inland
本文著重對自動識別系統（ ais - automaticidentificationsystem ）設備的高斯濾波最小頻移鍵控（ gmsk - gaussianfilteredminimunfrequencyshiftkeying ）基帶調制解調信號進行了模擬研究，並在模擬的基礎上，在ti的dsp上實現了基帶信號的調制解調，為國內研製ais系統儲備了關鍵技術。 -
At the same time, it uses a frequency translator to obtain a frequency shift, which is equal to the brillouin frequency in fiber. then the detecting pulsed light and the cw reference light can coherent. this method greatly improved the system ’ s sensitive and signal to noise ratio ( snr )
同時在探測光路中引入一個光移頻環路，使探測光移頻后再經光纖中布里淵頻移，其後向布里淵散射光頻率與參考光束大致相當，可進行相干自外差探測，大大提高了系統的探測靈敏度以及系統的信噪比。 -
In this paper, bit - error rate performance analyses are presented for coded and un - coded frequency hopping m - ary frequency - shift keyed systems under the condition of additive white gaussian noise ( awgn ) and partial band noise jamming and multitone jamming. the use of error - correct codes provide a way to improve the performance of frequency hopping system, particularly the use of reed - solomon code in a fh system under the condition of partial band noise jamming can greatly improve the performance of system. so we provide the way of coding and decoding of rs code in c language. in the end, we offer the simulation of the performance of time diversity fh / 2fsk system over partial band jamming noise channels
第一章為緒論，敘述跳頻通信的發展趨勢，以及基本概念，第二章及第三章介紹提高抗部分頻帶干擾的前向糾錯碼reed - solomon碼的原理和實現方法。第四章研究跳頻通信系統在各種干擾條件下的性能。最後在第五章以fh mfsk系統為例，探討在部分頻帶干擾下的系統性能，並進行計算機模擬，模擬結果表明採用分集技術和各種編碼技術對于系統的性能改善具有明顯的效果。 -
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。 -
The ministry of railway has developed two kinds of frequency - shift track circuits based on the primary 4 - information frequency - shift system : 18 - information frequency - shift auto - blocking track circuit made in china and um - 71 jointless track circuit made in france, and put them into use on some important lines. but at the mean while, the safety of running train becomes austerer and austerer
鐵道部根據我國國情，在原有4信息移頻制式的基礎上，研製開發了兩種移頻軌道電路:國產18信息移頻自動閉塞系統和法國um - 71無絕緣軌道電路系統，並將其應用到我國部分主要線路上。 -
System capability introduction of hai zhi sheng digital shift frequency teaching power amplfier
海之升數字移頻擴聲系統性能簡介： -
Space - time block codes ( stbc ) based on orthogonal design has attracts enough attentions in its applications in mimo - ofdm systems for its full diversity exploiting and low coding / decoding complexity. these applications include not only system performance improvement, but also reduction of the peak to average power ratio in mimo - ofdm systems. under these backgrounds, this paper first studies space - time block codes under the single carrier, flat fading situation, discusses the encoding / decoding principle and its performance under different channels. then, the author focused on the performance of space - time codes under time selective and frequency selective channels, uncovered the fundamental cause of how maximum doppler shift and power delay profile influences the performance of space - time codes through deduction and simulation
在上述背景下，本文以單載波，平坦衰落通道下的空時分組碼為切入點，深入分析了其編譯碼原理和在不同通道情況下的性能;以此為基礎，後文展開了對空時分組碼在多載波，時間選擇性和頻率選擇性衰落通道下的性能研究，通過理論推導和充分的模擬，揭示了空時/頻分組碼在時頻選擇性衰落通道中的性能變化的根本原因;在以上對多載波系統中空時分組碼的研究的過程中，作者發現了空時分組碼在降低系統峰平比方面應用的可行性，提出了一種降低峰平比的新方法。 -
We develop and produce the equipment of amplifiers. the main products are as follows : digital conference system, digital frequency shift amplifiers for teaching, long distance network conference system, simultaneous interpretation system and microphone for conference and special purpose. haisheng company has been dedicating to producing professional audio frequency equipment for conference and teaching
主要產品有：數字移頻擴聲設備dsp聲反饋抑制擴聲設備數字化會議系統同聲傳譯系統網會通網路會議用usb speaker phone回聲消除器界面話筒會議式鵝頸話筒高保真會議音柱專業麥克風等。 -
A signal - generated scheme that is used in high solution ac source is presented based on the reasonable usage of system source. by discussing the methods of counter - output, pll ( phase - locked loop ) - output and dds ( direct digital synthesization ) - output, dds - based dummy - space method is brought out and it converts the time problem into space, improves the resolution of both frequency and phase - shift
通過對計數器輸出法、基於鎖相環單片機合成及基於dds （ directdigitalsynthesization ）的單片機合成幾種方法的討論，引出一種基於dds的虛擬空間法，將時間上所面臨的問題轉化到內存空間上進行處理，極大地提高了交流電源的調頻、移相精度。 -
Down link channel of new generation space tt & c system generally select qpsk as its modulation mode. firstly, carrier synchronization of qpsk is studied in the thesis, and then the key question - carrier synchronization in low snr and severe doppler frequency shift is systemic analyzed. in addition, different existing project are analyzed and compared
新一代航天測控系統的下行通道一般選擇qpsk作為其信號調制方式，本文首先研究了qpsk的載波同步問題，對其中的關鍵問題? ?低信噪比及大多普勒頻移情況下的載波同步進行了系統的分析，對現有的不同方案進行了分析與比較。 -
The adaptive sr, studied in this thesis, means that the system automatically selecting parameter with a recursive algorithm, not adaptively adding noise. a parallel connection sr system is introduced and its application in digital frequency shift modulation signal transmission is discussed
我們初步提出了參數自適應隨機共振的思想以及收斂演算法，同時，我們還研究了數字信號載波調制傳輸中的並聯隨機共振系統。
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