3 ) the new types of photonic devices based on sampled grating : multiple wavelength laser , wavelength multiplexer / demultiplexer , reconfigurable optical add / drop multiplexer , optical fiber sensor , and multiple channels dispersion compensator 3 )取樣光柵構(gòu)成的新型光子學器件:多波長激光器、波分復用解復用器、重構(gòu)型光分插復用器、光纖傳感器及多信道色散補償器在光纖通信中的應用前景。
Without the central switch a lot of channels and tracks are shared by many users , the cost of the channels is reduced and the utilization factor of them is improved . user can call others by dialing the number , and the dialing is simple and quick 本文給出了有限用戶的呼損率公式和有限用戶多信道共用系統(tǒng)的信道配置方法,并可根據(jù)實際話務量、系統(tǒng)用戶數(shù)、呼損率配置共用繩路數(shù)和中繼線對數(shù)。
The author analyzed layered coding , multi description coding , technology of recover and hiding of errors , providing the approach " a approach of a multi description coding base on space domain dividing " , and then give a experiment to testify it 作者在文中較為詳細的分析介紹流媒體編碼中的分層編碼、多描述編碼和錯誤恢復隱藏機制,提出“基于空域分離多信道的多描述編碼方案” ,并佐以實驗數(shù)據(jù)驗證。
The source and the regularity of deviation when erlang b formula or the corresponding channel utilization ratio formula is used in a limited user system is dissected , and the condition available of the two groups of formulas are pointed out 由此不僅揭示了愛爾蘭b公式和相應信道利用率公式用于有限用戶系統(tǒng)時會有較大偏差的根源,剖析了偏差的規(guī)律性,而且得到了適用于有限用戶多信道共用系統(tǒng)的修正公式。
Adopting the technique of the multi - channel share which has already been widely used in communication fields such as satellite communication and mobile communication is an effective method to increase the capacities of communication system and the utilization factor of the channels 多信道共用技術(shù)是提高通信系統(tǒng)容量和信道利用率從而實現(xiàn)信道擴容的一種有效方法,現(xiàn)已在衛(wèi)星通信、移動通信等通信領(lǐng)域中得到應用。
In this thesis , the multi - channel sharing system is considered as a stochastic service system . based on the steady state solution of the birth and death process which state space is a limited set , utilized m / m / n / n / m queue model , the call congestion ratio formula and the channel utilization ratio formula fitting to the limited user system are derived . drawing support from the visual data analyzing function of the software matlab , the value divergence between the formulas and the corresponding one fitting to the infinite user system are compared 本文將多信道共用通信系統(tǒng)視為一個隨機服務系統(tǒng),根據(jù)有限狀態(tài)生滅過程的穩(wěn)態(tài)解,利用m m n n和m m n n m兩類排隊模型,分別推導出了無限用戶和有限用戶兩類多信道共用系統(tǒng)的呼損率公式和信道利用率公式;借助于matlab的可視化數(shù)據(jù)分析功能,比較了這兩組公式在數(shù)值上的差異;指明了兩組公式的適用條件。
Telephone communication is the most widely employed ways of communication in the world . telephone communication is becoming more and more important as the national economic reform deepens . dynamic channel borrowing assignment mode is an effective method in communication channel expansion . although it has been put into practical use in satellite communication and mobile communication , no one has attempted to apply it to telephone line expansion . in this paper the author expands the telephone line via dynamic channel borrowing assignment mode , ascertains the expansion scheme , designs the circuit of hardware in telephone line expansion device , draws up software programme , analyses the call lose after using the expansion device theoretically and then experiments to verify it . eight subscribers can share one or two telephone lines with the help of the telephone line expansion device with each phone a sole number . this makes it possible for subscribers to use any free telephone line . thus increasing the number of subscriber and utilization ration of telephone line . in addition . this project makes it possible for expansion subscribers to communicate directly while not to make use of outer line . which further decreased the system call lose 多信道共用是通信通道擴容的一種有效的方法,已在衛(wèi)星通信、移動通信中得到應用,但尚未應用到電話線路擴容中。本文利用多信道共用原理對電話線路進行擴容,確定了多信道共用方式電話線路擴容的設計研究方案,研究設計了電話線路擴容器的硬件電路,編制了電話線路擴容器的軟件,并對使用電話線路擴容器后的呼損進行了理論分析及試驗研究。本文研究設計的多信道共用方式電話線路擴容器可以使8個用戶共用1 2對電話線路,每部用戶話機都具有獨立的電話號碼,可以利用任一空閑的電話線路,故能夠增加電話用戶,提高電話線路的利用率。
In this article , based on the knowledge of stochastic process and combined with the software matlab , the configuration of shared lines for the limited users system is simulated and analyzed , and the relationship among the call congestion ( b ) , the shared ! ines ( n ) , the users ( m ) , the traffic ( a ) and the utilization factor of telephone lines is confirmed . according to the principle , the method of optional configuration of the shared lines is proposed 本文利用隨機過程理論知識,結(jié)合matlab軟件對有限用戶系統(tǒng)中多信道共用的共用線路配置進行可視化仿真、分析和研究,確定了呼損b與共用線路數(shù)n 、擴容用戶數(shù)m 、話務量a及線路利用率之間的關(guān)系,給出共用線路的最優(yōu)配置方法。
For power control of listening users , forward power control method are introduced based on full , multichannel , filtered report , and collision method etc . the full report method has redundancy report information , and its real - time performance is bad , multichannel report is introduced to improve the real - time performance , and filtered report is introduced to eliminate the redundancy information , finally the collision method introduced can not only get higher real - time performance but also diminish the redundancy information ; 2 . in order to meet the requirements of making the dynamic simulation of trunking group system , the ms ’ s random move equation is brought forward , the simulation of ms ’ s distribution is done and the integrated channel model are presented ; 3 . the smart predicative model of power control is introduced to overcome the delay and track the change of the complicated network , with this model , the power control ‘ s performance is greatly improved 全匯報方法存在冗余的匯報信息,而且實時性較差,為了改善實時性提出了多信道的匯報方式,為了改善冗余匯報而提出了篩選法,最后介紹的碰撞法在減少冗余信息的同時又提高了實時性;二、為了集群功率控制動態(tài)仿真的需要,提出了移動臺的隨機運動方程,進行了有關(guān)移動臺的分布仿真,建立了綜合的信道模型;三、希望克服延時和跟蹤復雜網(wǎng)絡環(huán)境變化,提出了功率控制的智能預測模型,通過智能預測模型可以改善功率控制的性能,著重介紹了采用神經(jīng)網(wǎng)絡的方法實現(xiàn)智能預測的通用模型,從而跟蹤復雜多變的無線環(huán)境,諸如慢衰落及快衰落(包括多徑衰落、多普勒效應所引起的衰落)等網(wǎng)絡特征,達到預測功率需求;四、采用二級正交碼和智能天線(空分多址)的方法進行組內(nèi)用戶的識別,改進功率控制效果;五、話權(quán)用戶的前向和反向功率控制方法;六、對引入gota的cdma系統(tǒng)提出了復合容量表示方法,并作容量分析,探討有關(guān)gota系統(tǒng)的qos問題。
The technique of the multi - channels sharing and the bus topological structure are adopted in the system , which does n ' t set the central switch and which not only can realize many users share a few explosion - proof channels , but also reduce the cost of the channels , while improving the utilization factor of them . the users " extension is flexible and convenient . the system has the functions of amplifying call and telephone talk 該系統(tǒng)不設主機,采用多信道共用技術(shù)和總線式拓撲結(jié)構(gòu),實現(xiàn)多用戶共用少數(shù)防爆繩路,降低了繩路成本且提高了利用率;用戶擴展靈活、方便:具有擴音呼叫和電話對講功能;工程布線簡單,費用低,工期短。