This is a simulator written in Tcl to simulate a network node carrying GSM and GPRS traffics with QoS mechanisms. The payload type including circuit-switched voice, VoIP and web traffic, and the performance including packet drop, delay can be analyzed. The implemented QoS mechanism is DiffServ, with 4 RED queues for different services with different priorities.
標簽： simulator carrying simulate traffics
上傳時間： 2014-01-01
上傳用戶：1583060504
同步技術是跳頻通信系統的關鍵技術之一，尤其是在快速跳頻通信系統中，常規跳頻通信通過同步字頭攜帶相關碼的方法來實現同步，但對于快跳頻來說，由于是一跳或者多跳傳輸一個調制符號，難以攜帶相關碼。對此引入雙跳頻圖案方法，提出了一種適用于快速跳頻通信系統的同步方案。采用短碼攜帶同步信息，克服了快速跳頻難以攜帶相關碼的困難。分析了同步性能，仿真結果表明該方案同步時間短、虛警概率低、捕獲概率高，同步性能可靠。 Abstract: Synchronization is one of the key techniques to frequency-hopping communication system， especially in the fast frequency hopping communication system. In conventional frequency hopping communication systems， synchronization can be achieved by synchronization-head which can be used to carry the synchronization information， but for the fast frequency hopping， Because modulation symbol is transmitted by per hop or multi-hop， it is difficult to carry the correlation code. For the limitation of fast frequency hopping in carrying correlation code， a fast frequency-hopping synchronization scheme with two hopping patterns is proposed. The synchronization information is carried by short code， which overcomes the difficulty of correlation code transmission in fast frequency-hopping. The performance of the scheme is analyzed， and simulation results show that the scheme has the advantages of shorter synchronization time， lower probability of false alarm， higher probability of capture and more reliable of synchronization.
上傳時間： 2013-11-23
上傳用戶：mpquest
Abstract-In this paper, simple autonomous chaotic circuits coupled by resistors are investigated. By carrying out computer calculations and circuit experiments, irregular self-switching phenomenon of three spatial patterns characterized by the phase states of quasi-synchronization of chaos can be observed from only four simple chaotic circuits. This is the same phenomenon as chaotic wandering of spatial patterns observed very often from systems with a large number of degrees of freedom. Namely, one of spatial-temporal chaos observed from systems of large size can be also generated in the proposed system consisting of only four chaotic circuits. A six subcircuits case and a coupled chaotic circuits networks are also studied, and such systems are confirmed to produce more complicated spatio-temporal phenomena.
標簽： investigated Abstract-In autonomous resistors
上傳時間： 2014-06-09
上傳用戶：h886166
Ultra-wideband (UWB) technology enables high data-rate short-range communica- tion, in excess of hundredmegabit-per-secondsand up to multi-gigabit-per-seconds, over a wide spectrum of frequencies, while keeping power consumption at low lev- els. This low power operation results in a less-interfering co-existence with other existed communication technologies (e.g., UNII bands). In addition to carrying a huge amount of data over a distance of up to 230 feet at very low power (less than 0.5mW), the UWB signal has the ability to penetrate through the doors and other obstacles that tend to reflect signals at more limited bandwidths and higher power densities.
標簽： Silicon-Based Front-Ends RF
上傳時間： 2020-06-01
上傳用戶：shancjb
Thanks to the advances in micromachining fabrication technologies and significant cost reduction due to mass production, miniature sensors of angular rate, or gyroscopes, found their way into the everyday life of every user of modern gadgets, such as smart phones, tablets or even wristwatches. Often without realising, many of us are carrying in our pockets fully equipped with all necessary sensors complete inertial navigation systems that not so long ago were available only for advanced vehicles in sea, land, air or space. Accelerometers and gyroscopes are found in specifications of any gadget supposed to react to user movements. And one of the most commonly used type of gyroscopes used to developed these systems is Coriolis vibratory gyroscope (CVG).
標簽： Gyroscopes Vibratory Coriolis
上傳時間： 2020-06-06
上傳用戶：shancjb
Introduction to Radio Frequency Identification (RFID): RFID is a wireless modulation and demodulation technique for automatic identification of objects, tracking goods, smart logistics, and access con- trol. RFID is a contactless, usually short‐distance transmission and reception technique for unique ID data transfer from a tagged object to an interrogator (reader). The generic configuration of an RFID system comprises (i) an ID data‐carrying tag, (ii) a reader, (iii) a middleware, and (iv) an enterprise application.
標簽： Chipless_Radio_Frequency_Identifi cation
上傳時間： 2020-06-08
上傳用戶：shancjb
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