wireless time signal 中文意思是什麼
wireless time signal
解釋
無線電報時信號-
As the key block of the wireless communication transmitter in rf, it is very useful in improving the output power and efficiency, lowering the loss of the supply, lowering the size and the weight, lengthening the time of communication. class e power amplifier which is suitable to amplify envelop signal is very important in modern communication system
功率放大器（ pa ）作為無線通信射頻發射機中不可缺少的關鍵電路，對于提高手機的功率效率、降低電源損耗、減小體積重量、延長通話時間有著舉足輕重的作用，而適用於恆包絡信號放大的e類功率放大器，更是在現代通信系統中佔有十分重要的地位。 -
In order to utilize the frquency resource adequately and increase the capacity of mobile communication system, the wireless electric wave propagation of existing mobile system always adopts the microcell structure. forecasting the path loss characteristic of electric wave accurately can provide the necessary condition for the layout and design of wireless network, at the same time it is a precondition for the research on the microcell mobile system. the methods of forecasting of wireless electric wave propagation can divide into two parts : one is pluse and respond, that is establish the empirical model based on experimental and statistical data ; the other is ray tracing method, that is establish the deterministic model based on theoretical analyse. the paper discuss the characteristic of wireless signal electric wave transmition in symmetrical atmosphere of earth, and introduce the common path loss transmition model in land mobile communication system, also point out the localization of these models based on experiential methods
而精確預測無線電波傳播路徑損耗特性，則為合理的微蜂窩無線網路規劃、設計提供了必要條件，同時也是研究微蜂窩移動通信系統性能的前提。無線電波傳播預測的方法分為兩類：一是用沖激響應法，即根據實驗、統計所得數據建立經驗性傳播預測模型；另一種是用射線跟蹤方法，即依據理論分析來建立確定性的傳播預測模型。本文首先討論了在地球表面均勻大氣中的無線電波傳播的基本特性，介紹了陸地移動通信系統中常用的幾種電波傳播路徑損耗經驗性預測模型，並指出了這些經驗性傳播模型對于微蜂窩小區無線電波傳播特性研究的局限性。 -
Gps is a planet wireless conductance system which is global and all - weather, gps can offer high precision time orientation information to infinite user, clock precision reachs 10 ? 6 magnitude 。 not only changes traditional time method of quartz crystal clock, but also replaces wireless shortwave and even more lowfrequency signal and tv signal whose overlay range is limited and low precision, offers advantage to geology field task, achieve automatization and high precision of seismic flow observation
利用gps授時信號全方位、全天候、連續性、實時性和高精度的特點，以gps信號為基準來校準本地時鐘（晶體振蕩時鐘或原子鐘） ，將gps接收機輸出信號的長期穩定度和恆溫晶振的短期穩定度相結合，應用大規模可編程邏輯器件，設計和實現了由pc104控制的實時在線授時系統。 -
Once has the bandits and thieves to intrude guards against the place, the detector launches the wireless coded signal immediately, the networking center number which installs when is apart from defense area 150 meter within the main engine to send out the police whistle sound to report to the police immediately, reports to the police dials to establish in advance or reports to the police the telephone, the handset number, answers in the police telephone to return puts user pre - record to report to the police the pronunciation, long - distance reports to the police, simultaneously comes the real - time transmission through the internet to deploy troops for defense, to withdraw from a defended position, to report to the police and so on the condition, inquires the historic record through the computer network
該系統還採用美國進口原裝晶元與先進的無線數字高頻技術微電腦cpu控制器主機組成。在防範地點安裝好主機后，並設置在布防狀態。一旦有盜賊闖入防範地點，探測器立刻發射無線編碼信號，安裝在距防區150米以內的主機立即發出警笛聲報警，報警時撥打預先設定的聯網中心號碼或報警電話手機號碼，接警電話里回放用戶預錄的報警語音，遠程報警，同時通過網際網路來實時傳遞布防撤防報警等狀態，通過電腦網路來查詢歷史記錄。 -
However, the wireless communication has the shortages of error often, time delay, and limited broad because of the requirement of large amount of data flow, and high true - false ratio for the video signal. thus the ratio in wireless channel is much larger than that of the wire environment. furthermore, it has large variations with the changes of positions and directions of basement and terminals
由於視頻業務的數據量大、對誤比特率要求高，無線通道又具有易錯、時變和帶限的特點，因此通道的誤比特率要比有線環境大得多，且隨著基站和終端位置、方向的改變而變化很大。 -
A signal processing method comprises receiving a first signal for wireless communication, obtaining an approximate of a non - channel function in the first signal, separating the approximate of the non - channel function from the first signal to obtain a second signal that includes a time - varying channel function, and processing the second signal to obtain a user signal
本發明提供一個信號處理方法，包括接收第一個無線信號；估計第一個信號中的脈沖成形失真；從第一個信號中分離出該脈沖成形失真以獲得第二個信號；以及處理第二個信號以獲得一個用戶信號。 -
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。 -
It has been proven that the spread spectrum technologies have good capabilities of overcoming isi in electromagnetic wireless channel. the feasibilities of their applications to underwater acoustic channel have been analyzed, the frequency hopping technology is chosen. instead of using time - frequency diversity, convolutional coding and viterbi decoding are employed to combat signal fading, consequently the bit - rate and bit - error - rate performance of the underwater acoustic voice communication system can be balanced and controlled
由於擴頻技術在抗碼間干擾方面具有優良的特性，因此在分析了各種擴頻技術于本研究應用的可行性之後，確定了跳頻技術作為具體實現方案；在克服幅度衰落方面，選用卷積編碼和維特比譯碼方法來替代原有的分集技術以綜合調節系統的通信速率與誤碼性能，達到差錯可控的目的。 -
Because of the affection of noise and signal fading, in order to high data rate access and high quality, wireless communication need new technology to improve the link reliability and enhance the spectrum efficiency. mimo ( multiple input and multiple output ) can enhance the spectrum efficiency and increase channel capacity greatly, and reduce the multipath affection without spectrum band and power increasing. the 3th generation mobile communication wcdma is coming, with the purpose of putting mimo, stbc ( space time block coding ), space diversity into practice of wcdma systems, in order to lay the foundation of 3g toward 4g, this dissertation has done some research under this background
在發射機和接收機使用多個天線進行數據傳輸的多輸入多輸出（ mimo ）技術，可以在不增加帶寬和天線發送功率的條件下，成倍的提高頻譜利用率，提高系統的通道容量，還可以抗多徑干擾。第三代移動通信wcdma即將到來，為了將多天線技術（ mimo ） ，空間分集技術，空時編碼技術用到wcdma系統中去，為第三代移動通信向第四代移動通信系統平穩過渡奠定一定的基礎，需要做一些理論上的研究。 -
The system applied solar energy to supplying power, using sigle - chip microcomputer to control automatically the traffic signal lights and time - show, equiped wireless remote controller for the convenience of the traffic cop to direct
本系統應用太陽能供電，採用單片機自動控制交通信號燈及時間顯示，配備無線遙控式開關以方便交警的應急指揮。
分享友人