A novel met hod t o p artially compensate sigma2delta shap ed noise is p rop osed. By injecting t he comp en2
sation cur rent int o t he p assive loop f ilte r during t he delay time of t he p hase f requency detect or ( PFD) , a maximum
reduction of t he p hase noise by about 16dB can be achieved. Comp a red t o ot he r compensation met hods , t he tech2
nique p rop osed he re is relatively simple and easy t o implement . Key building blocks f or realizing t he noise cancel2
lation , including t he delay va riable PFD and comp ensation cur rent source , a re sp ecially designed. Bot h t he behavior
level and circuit level simulation results a re p resented.
基于T i n y O S 的無線傳感器網(wǎng)絡體系結(jié)構(gòu)
無線傳感器網(wǎng)絡WSN(Wireless Sensor Network) 由部署在監(jiān)測區(qū)域內(nèi)大量廉價的傳感器節(jié)點組成,通過
無線通信方式形成multi2hop 自組織的網(wǎng)絡系統(tǒng),其目的是協(xié)作地感知、采集和處理網(wǎng)絡覆蓋區(qū)域中感知
對象的信息,并發(fā)送給觀察者。本文從分析無線傳感器節(jié)點Mica 和其上運行的操作系統(tǒng)TinyOS 出發(fā),
著重描述無線傳感器網(wǎng)絡節(jié)點應用程序體系結(jié)構(gòu)和消息通信機制。
