在研究傳統家用燃氣報警器的基礎上,以ZigBee協議為平臺,構建mesh網狀網絡實現網絡化的智能語音報警系統。由于傳感器本身的溫度和實際環境溫度的影響,傳感器標定后采用軟件補償方法。為了減少系統費用,前端節點采用半功能節點設備,路由器和協調器采用全功能節點設備,構建mesh網絡所形成的家庭內部報警系統,通過通用的電話接口連接到外部的公用電話網絡,啟動語音模塊進行報警。實驗結果表明,在2.4 GHz頻率下傳輸,有墻等障礙物的情況下,節點的傳輸距離大約為35 m,能夠滿足家庭需要,且系統工作穩定,但在功耗方面仍需進一步改善。
Abstract:
On the basis of studying traditional household gas alarm system, this paper proposed the platform for the ZigBee protocol,and constructed mesh network to achieve network-based intelligent voice alarm system. Because of the sensor temperature and the actual environment temperature, this system design used software compensation after calibrating sensor. In order to reduce system cost, semi-functional node devices were used as front-end node, however, full-function devices were used as routers and coordinator,constructed alarm system within the family by building mesh network,connected to the external public telephone network through the common telephone interface, started the voice alarm module. The results indicate that nodes transmit about 35m in the distance in case of walls and other obstacles by 2.4GHz frequency transmission, this is able to meet family needs and work steadily, but still needs further improvement in power consumption.
為了能夠滿足基站易于選址、優質快速的建站要求和易維護、低成本、高可靠的運行要求,本文對以方艙來實現一體化結構基站做出一番探討。從系統設計的觀點闡述了移動通信高性能基站天線設計的幾個關鍵問題,介紹了智能天線技術在基站中的應用,并且用HFSS軟件仿真了一種新型的對稱陣子天線,該天線駐波比小于2的帶寬可以達到60%,具有良好的寬頻帶特性。
Abstract:
In order to meet the station construction requirement of easy site selection and fast base station, and meet the operational requirement of easy maintenance, low cost and high reliability, this paper discussed the unified architecture base station using shelter. Several key problems of high performance mobile communication base station antenna were illustrated from the view of system design, the application of smart antenna in base station was also introduced. And a novel dipole antenna was simulated by using HFSS, the VSWR of the antenna is less than 2, and the bandwidth was reach to 60%. So it has good broadband properties.